With THP, current check of offset:
VM_BUG_ON_PAGE(page->index != offset, page);
is no longer accurate. Update it to:
VM_BUG_ON_PAGE(page_to_pgoff(page) != offset, page);
Link: http://lkml.kernel.org/r/20190801184244.3169074-4-songliubraving@fb.com
Signed-off-by: Song Liu <songliubraving@fb.com>
Acked-by: Rik van Riel <riel@surriel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Similar to previous patch, pagecache_get_page() avoids race condition with
truncate by checking page->mapping == mapping. This does not work for
compound pages. This patch let it check compound_head(page)->mapping
instead.
Link: http://lkml.kernel.org/r/20190801184244.3169074-3-songliubraving@fb.com
Signed-off-by: Song Liu <songliubraving@fb.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Enable THP for text section of non-shmem files", v10;
This patchset follows up discussion at LSF/MM 2019. The motivation is to
put text section of an application in THP, and thus reduces iTLB miss rate
and improves performance. Both Facebook and Oracle showed strong
interests to this feature.
To make reviews easier, this set aims a mininal valid product. Current
version of the work does not have any changes to file system specific
code. This comes with some limitations (discussed later).
This set enables an application to "hugify" its text section by simply
running something like:
madvise(0x600000, 0x80000, MADV_HUGEPAGE);
Before this call, the /proc/<pid>/maps looks like:
00400000-074d0000 r-xp 00000000 00:27 2006927 app
After this call, part of the text section is split out and mapped to
THP:
00400000-00425000 r-xp 00000000 00:27 2006927 app
00600000-00e00000 r-xp 00200000 00:27 2006927 app <<< on THP
00e00000-074d0000 r-xp 00a00000 00:27 2006927 app
Limitations:
1. This only works for text section (vma with VM_DENYWRITE).
2. Original limitation #2 is removed in v3.
We gated this feature with an experimental config, READ_ONLY_THP_FOR_FS.
Once we get better support on the write path, we can remove the config and
enable it by default.
Tested cases:
1. Tested with btrfs and ext4.
2. Tested with real work application (memcache like caching service).
3. Tested with "THP aware uprobe":
https://patchwork.kernel.org/project/linux-mm/list/?series=131339
This patch (of 7):
Currently, filemap_fault() avoids race condition with truncate by checking
page->mapping == mapping. This does not work for compound pages. This
patch let it check compound_head(page)->mapping instead.
Link: http://lkml.kernel.org/r/20190801184244.3169074-2-songliubraving@fb.com
Signed-off-by: Song Liu <songliubraving@fb.com>
Acked-by: Rik van Riel <riel@surriel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: William Kucharski <william.kucharski@oracle.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When allocating hugetlbfs pool pages via /proc/sys/vm/nr_hugepages, the
pages will be interleaved between all nodes of the system. If nodes are
not equal, it is quite possible for one node to fill up before the others.
When this happens, the code still attempts to allocate pages from the
full node. This results in calls to direct reclaim and compaction which
slow things down considerably.
When allocating pool pages, note the state of the previous allocation for
each node. If previous allocation failed, do not use the aggressive retry
algorithm on successive attempts. The allocation will still succeed if
there is memory available, but it will not try as hard to free up memory.
Link: http://lkml.kernel.org/r/20190806014744.15446-5-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mike Kravetz reports that "hugetlb allocations could stall for minutes or
hours when should_compact_retry() would return true more often then it
should. Specifically, this was in the case where compact_result was
COMPACT_DEFERRED and COMPACT_PARTIAL_SKIPPED and no progress was being
made."
The problem is that the compaction_withdrawn() test in
should_compact_retry() includes compaction outcomes that are only possible
on low compaction priority, and results in a retry without increasing the
priority. This may result in furter reclaim, and more incomplete
compaction attempts.
With this patch, compaction priority is raised when possible, or
should_compact_retry() returns false.
The COMPACT_SKIPPED result doesn't really fit together with the other
outcomes in compaction_withdrawn(), as that's a result caused by
insufficient order-0 pages, not due to low compaction priority. With this
patch, it is moved to a new compaction_needs_reclaim() function, and for
that outcome we keep the current logic of retrying if it looks like
reclaim will be able to help.
Link: http://lkml.kernel.org/r/20190806014744.15446-4-mike.kravetz@oracle.com
Reported-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Tested-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After commit "mm, reclaim: make should_continue_reclaim perform dryrun
detection", closer look at the function shows, that nr_reclaimed == 0
means the function will always return false. And since non-zero
nr_reclaimed implies non_zero nr_scanned, testing nr_scanned serves no
purpose, and so does the testing for __GFP_RETRY_MAYFAIL.
This patch thus cleans up the function to test only !nr_reclaimed upfront,
and remove the __GFP_RETRY_MAYFAIL test and nr_scanned parameter
completely. Comment is also updated, explaining that approximating "full
LRU list has been scanned" with nr_scanned == 0 didn't really work.
Link: http://lkml.kernel.org/r/20190806014744.15446-3-mike.kravetz@oracle.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "address hugetlb page allocation stalls", v2.
Allocation of hugetlb pages via sysctl or procfs can stall for minutes or
hours. A simple example on a two node system with 8GB of memory is as
follows:
echo 4096 > /sys/devices/system/node/node1/hugepages/hugepages-2048kB/nr_hugepages
echo 4096 > /proc/sys/vm/nr_hugepages
Obviously, both allocation attempts will fall short of their 8GB goal.
However, one or both of these commands may stall and not be interruptible.
The issues were initially discussed in mail thread [1] and RFC code at
[2].
This series addresses the issues causing the stalls. There are two
distinct fixes, a cleanup, and an optimization. The reclaim patch by
Hillf and compaction patch by Vlasitmil address corner cases in their
respective areas. hugetlb page allocation could stall due to either of
these issues. Vlasitmil added a cleanup patch after Hillf's
modifications. The hugetlb patch by Mike is an optimization suggested
during the debug and development process.
[1] http://lkml.kernel.org/r/d38a095e-dc39-7e82-bb76-2c9247929f07@oracle.com
[2] http://lkml.kernel.org/r/20190724175014.9935-1-mike.kravetz@oracle.com
This patch (of 4):
Address the issue of should_continue_reclaim returning true too often for
__GFP_RETRY_MAYFAIL attempts when !nr_reclaimed and nr_scanned. This was
observed during hugetlb page allocation causing stalls for minutes or
hours.
We can stop reclaiming pages if compaction reports it can make a progress.
There might be side-effects for other high-order allocations that would
potentially benefit from reclaiming more before compaction so that they
would be faster and less likely to stall. However, the consequences of
premature/over-reclaim are considered worse.
We can also bail out of reclaiming pages if we know that there are not
enough inactive lru pages left to satisfy the costly allocation.
We can give up reclaiming pages too if we see dryrun occur, with the
certainty of plenty of inactive pages. IOW with dryrun detected, we are
sure we have reclaimed as many pages as we could.
Link: http://lkml.kernel.org/r/20190806014744.15446-2-mike.kravetz@oracle.com
Signed-off-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Tested-by: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cgroup v1 memcg controller has exposed a dedicated kmem limit to users
which turned out to be really a bad idea because there are paths which
cannot shrink the kernel memory usage enough to get below the limit (e.g.
because the accounted memory is not reclaimable). There are cases when
the failure is even not allowed (e.g. __GFP_NOFAIL). This means that the
kmem limit is in excess to the hard limit without any way to shrink and
thus completely useless. OOM killer cannot be invoked to handle the
situation because that would lead to a premature oom killing.
As a result many places might see ENOMEM returning from kmalloc and result
in unexpected errors. E.g. a global OOM killer when there is a lot of
free memory because ENOMEM is translated into VM_FAULT_OOM in #PF path and
therefore pagefault_out_of_memory would result in OOM killer.
Please note that the kernel memory is still accounted to the overall limit
along with the user memory so removing the kmem specific limit should
still allow to contain kernel memory consumption. Unlike the kmem one,
though, it invokes memory reclaim and targeted memcg oom killing if
necessary.
Start the deprecation process by crying to the kernel log. Let's see
whether there are relevant usecases and simply return to EINVAL in the
second stage if nobody complains in few releases.
[akpm@linux-foundation.org: tweak documentation text]
Link: http://lkml.kernel.org/r/20190911151612.GI4023@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Thomas Lindroth <thomas.lindroth@gmail.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mem_cgroup_id_get() was introduced in commit 73f576c04b ("mm:memcontrol:
fix cgroup creation failure after many small jobs").
Later, it no longer has any user since the commits,
1f47b61fb4 ("mm: memcontrol: fix swap counter leak on swapout from offline cgroup")
58fa2a5512 ("mm: memcontrol: add sanity checks for memcg->id.ref on get/put")
so safe to remove it.
Link: http://lkml.kernel.org/r/1568648453-5482-1-git-send-email-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
constrained_alloc() calculates the size of the oom domain by using
node_spanned_pages which is incorrect because this is the full range of
the physical memory range that the numa node occupies rather than the
memory that backs that range which is represented by node_present_pages.
Sparsely populated nodes (e.g. after memory hot remove or simply sparse
due to memory layout) can have really a large difference between the two.
This shouldn't really cause any real user observable problems because the
oom calculates a ratio against totalpages and used memory cannot exceed
present pages but it is confusing and wrong from code point of view.
Link: http://lkml.kernel.org/r/20190829163443.899-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit ac311a14c6 ("oom: decouple mems_allowed from
oom_unkillable_task") changed has_intersects_mems_allowed() to
oom_cpuset_eligible(), but didn't change the comment.
Link: http://lkml.kernel.org/r/1566959929-10638-1-git-send-email-wang.yi59@zte.com.cn
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For an OOM event: print oom_score_adj value for the OOM Killed process to
document what the oom score adjust value was at the time the process was
OOM Killed. The adjustment value can be set by user code and it affects
the resulting oom_score so it is used to influence kill process selection.
When eligible tasks are not printed (sysctl oom_dump_tasks = 0) printing
this value is the only documentation of the value for the process being
killed. Having this value on the Killed process message is useful to
document if a miscconfiguration occurred or to confirm that the
oom_score_adj configuration applies as expected.
An example which illustates both misconfiguration and validation that the
oom_score_adj was applied as expected is:
Aug 14 23:00:02 testserver kernel: Out of memory: Killed process 2692
(systemd-udevd) total-vm:1056800kB, anon-rss:1052760kB, file-rss:4kB,
shmem-rss:0kB pgtables:22kB oom_score_adj:1000
The systemd-udevd is a critical system application that should have an
oom_score_adj of -1000. It was miconfigured to have a adjustment of 1000
making it a highly favored OOM kill target process. The output documents
both the misconfiguration and the fact that the process was correctly
targeted by OOM due to the miconfiguration. This can be quite helpful for
triage and problem determination.
The addition of the pgtables_bytes shows page table usage by the process
and is a useful measure of the memory size of the process.
Link: http://lkml.kernel.org/r/20190822173157.1569-1-echron@arista.com
Signed-off-by: Edward Chron <echron@arista.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the event of an oom kill, useful information about the killed process
is printed to dmesg. Users, especially system administrators, will find
it useful to immediately see the UID of the process.
We already print uid when dumping eligible tasks so it is not overly hard
to find that information in the oom report. However this information is
unavailable when dumping of eligible tasks is disabled.
In the following example, abuse_the_ram is the name of a program that
attempts to iteratively allocate all available memory until it is stopped
by force.
Current message:
Out of memory: Killed process 35389 (abuse_the_ram)
total-vm:133718232kB, anon-rss:129624980kB, file-rss:0kB,
shmem-rss:0kB
Patched message:
Out of memory: Killed process 2739 (abuse_the_ram),
total-vm:133880028kB, anon-rss:129754836kB, file-rss:0kB,
shmem-rss:0kB, UID:0
[akpm@linux-foundation.org: s/UID %d/UID:%u/ in printk]
Link: http://lkml.kernel.org/r/1560362273-534-1-git-send-email-jsavitz@redhat.com
Signed-off-by: Joel Savitz <jsavitz@redhat.com>
Suggested-by: David Rientjes <rientjes@google.com>
Acked-by: Rafael Aquini <aquini@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1) task_nodes = cpuset_mems_allowed(current);
-> cpuset_mems_allowed() guaranteed to return some non-empty
subset of node_states[N_MEMORY].
2) nodes_and(*new, *new, task_nodes);
-> after nodes_and(), the 'new' should be empty or appropriate
nodemask(online node and with memory).
After 1) and 2), we could remove unnecessary check whether the 'new'
AND node_states[N_MEMORY] is empty.
Link: http://lkml.kernel.org/r/20190806023634.55356-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
total_{migrate,free}_scanned will be added to COMPACTMIGRATE_SCANNED and
COMPACTFREE_SCANNED in compact_zone(). We should clear them before
scanning a new zone. In the proc triggered compaction, we forgot clearing
them.
[laoar.shao@gmail.com: introduce a helper compact_zone_counters_init()]
Link: http://lkml.kernel.org/r/1563869295-25748-1-git-send-email-laoar.shao@gmail.com
[akpm@linux-foundation.org: expand compact_zone_counters_init() into its single callsite, per mhocko]
[vbabka@suse.cz: squash compact_zone() list_head init as well]
Link: http://lkml.kernel.org/r/1fb6f7da-f776-9e42-22f8-bbb79b030b98@suse.cz
[akpm@linux-foundation.org: kcompactd_do_work(): avoid unnecessary initialization of cc.zone]
Link: http://lkml.kernel.org/r/1563789275-9639-1-git-send-email-laoar.shao@gmail.com
Fixes: 7f354a548d ("mm, compaction: add vmstats for kcompactd work")
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Yafang Shao <shaoyafang@didiglobal.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently there is a leak in init_z3fold_page() -- it allocates handles
from kmem cache even for headless pages, but then they are never used and
never freed, so eventually kmem cache may get exhausted. This patch
provides a fix for that.
Link: http://lkml.kernel.org/r/20190917185352.44cf285d3ebd9e64548de5de@gmail.com
Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Reported-by: Markus Linnala <markus.linnala@gmail.com>
Tested-by: Markus Linnala <markus.linnala@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When compiling a kernel with W=1, there are several of those warnings due
to arm64 overriding a field on purpose. Just disable those warnings for
both GCC and Clang of this file, so it will help dig "gems" hidden in the
W=1 warnings by reducing some noises.
mm/init-mm.c:39:2: warning: initializer overrides prior initialization
of this subobject [-Winitializer-overrides]
INIT_MM_CONTEXT(init_mm)
^~~~~~~~~~~~~~~~~~~~~~~~
./arch/arm64/include/asm/mmu.h:133:9: note: expanded from macro
'INIT_MM_CONTEXT'
.pgd = init_pg_dir,
^~~~~~~~~~~
mm/init-mm.c:30:10: note: previous initialization is here
.pgd = swapper_pg_dir,
^~~~~~~~~~~~~~
Note: there is a side project trying to support explicitly allowing
specific initializer overrides in Clang, but there is no guarantee it
will happen or not.
https://github.com/ClangBuiltLinux/linux/issues/639
Link: http://lkml.kernel.org/r/1566920867-27453-1-git-send-email-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace open-coded bitmap array initialization of init_mm.cpu_bitmask with
neat CPU_BITS_NONE macro.
And, since init_mm.cpu_bitmask is statically set to zero, there is no way
to clear it again in start_kernel().
Link: http://lkml.kernel.org/r/1565703815-8584-1-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If !area->pages statement is true where memory allocation fails, area is
freed.
In this case 'area->pages = pages' should not executed. So move
'area->pages = pages' after if statement.
[akpm@linux-foundation.org: give area->pages the same treatment]
Link: http://lkml.kernel.org/r/20190830035716.GA190684@LGEARND20B15
Signed-off-by: Austin Kim <austindh.kim@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Roman Penyaev <rpenyaev@suse.de>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Objective
---------
The current implementation of struct vmap_area wasted space.
After applying this commit, sizeof(struct vmap_area) has been
reduced from 11 words to 8 words.
Description
-----------
1) Pack "subtree_max_size", "vm" and "purge_list". This is no problem
because
A) "subtree_max_size" is only used when vmap_area is in "free" tree
B) "vm" is only used when vmap_area is in "busy" tree
C) "purge_list" is only used when vmap_area is in vmap_purge_list
2) Eliminate "flags".
;Since only one flag VM_VM_AREA is being used, and the same thing can be
done by judging whether "vm" is NULL, then the "flags" can be eliminated.
Link: http://lkml.kernel.org/r/20190716152656.12255-3-lpf.vector@gmail.com
Signed-off-by: Pengfei Li <lpf.vector@gmail.com>
Suggested-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The busy tree can be quite big, even though the area is freed or unmapped
it still stays there until "purge" logic removes it.
1) Optimize and reduce the size of "busy" tree by removing a node from
it right away as soon as user triggers free paths. It is possible to
do so, because the allocation is done using another augmented tree.
The vmalloc test driver shows the difference, for example the
"fix_size_alloc_test" is ~11% better comparing with default configuration:
sudo ./test_vmalloc.sh performance
<default>
Summary: fix_size_alloc_test loops: 1000000 avg: 993985 usec
Summary: full_fit_alloc_test loops: 1000000 avg: 973554 usec
Summary: long_busy_list_alloc_test loops: 1000000 avg: 12617652 usec
<default>
<this patch>
Summary: fix_size_alloc_test loops: 1000000 avg: 882263 usec
Summary: full_fit_alloc_test loops: 1000000 avg: 973407 usec
Summary: long_busy_list_alloc_test loops: 1000000 avg: 12593929 usec
<this patch>
2) Since the busy tree now contains allocated areas only and does not
interfere with lazily free nodes, introduce the new function
show_purge_info() that dumps "unpurged" areas that is propagated
through "/proc/vmallocinfo".
3) Eliminate VM_LAZY_FREE flag.
Link: http://lkml.kernel.org/r/20190716152656.12255-2-lpf.vector@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Pengfei Li <lpf.vector@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Uladzislau Rezki <urezki@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is no possibility for memmap to be NULL in the current codebase.
This check was added in commit 95a4774d05 ("memory-hotplug: update
mce_bad_pages when removing the memory") where memmap was originally
inited to NULL, and only conditionally given a value.
The code that could have passed a NULL has been removed by commit
ba72b4c8cf ("mm/sparsemem: support sub-section hotplug"), so there is no
longer a possibility that memmap can be NULL.
Link: http://lkml.kernel.org/r/20190829035151.20975-1-alastair@d-silva.org
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the function written to do it instead.
Link: http://lkml.kernel.org/r/20190827053656.32191-2-alastair@au1.ibm.com
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__pfn_to_section is defined as __nr_to_section(pfn_to_section_nr(pfn)).
Since we already get section_nr, it is not necessary to get mem_section
from start_pfn. By doing so, we reduce one redundant operation.
Link: http://lkml.kernel.org/r/20190809010242.29797-1-richardw.yang@linux.intel.com
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Tested-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The size argument passed into sparse_buffer_alloc() has already been
aligned with PAGE_SIZE or PMD_SIZE.
If the size after aligned is not power of 2 (e.g. 0x480000), the
PTR_ALIGN() will return wrong value. Use roundup to round sparsemap_buf
up to next multiple of size.
Link: http://lkml.kernel.org/r/20190705114826.28586-1-lecopzer.chen@mediatek.com
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Signed-off-by: Mark-PK Tsai <Mark-PK.Tsai@mediatek.com>
Cc: YJ Chiang <yj.chiang@mediatek.com>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sparse_buffer_alloc(xsize) gets the size of memory from sparsemap_buf
after being aligned with the size. However, the size is at least
PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION) and usually larger
than PAGE_SIZE.
Also, sparse_buffer_fini() only frees memory between sparsemap_buf and
sparsemap_buf_end, since sparsemap_buf may be changed by PTR_ALIGN()
first, the aligned space before sparsemap_buf is wasted and no one will
touch it.
In our ARM32 platform (without SPARSEMEM_VMEMMAP)
Sparse_buffer_init
Reserve d359c000 - d3e9c000 (9M)
Sparse_buffer_alloc
Alloc d3a00000 - d3E80000 (4.5M)
Sparse_buffer_fini
Free d3e80000 - d3e9c000 (~=100k)
The reserved memory between d359c000 - d3a00000 (~=4.4M) is unfreed.
In ARM64 platform (with SPARSEMEM_VMEMMAP)
sparse_buffer_init
Reserve ffffffc07d623000 - ffffffc07f623000 (32M)
Sparse_buffer_alloc
Alloc ffffffc07d800000 - ffffffc07f600000 (30M)
Sparse_buffer_fini
Free ffffffc07f600000 - ffffffc07f623000 (140K)
The reserved memory between ffffffc07d623000 - ffffffc07d800000
(~=1.9M) is unfreed.
Let's explicit free redundant aligned memory.
[arnd@arndb.de: mark sparse_buffer_free as __meminit]
Link: http://lkml.kernel.org/r/20190709185528.3251709-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20190705114730.28534-1-lecopzer.chen@mediatek.com
Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
Signed-off-by: Mark-PK Tsai <Mark-PK.Tsai@mediatek.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: YJ Chiang <yj.chiang@mediatek.com>
Cc: Lecopzer Chen <lecopzer.chen@mediatek.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
walk_system_ram_range() will fail with -EINVAL in case
online_pages_range() was never called (== no resource applicable in the
range). Otherwise, we will always call online_pages_range() with nr_pages
> 0 and, therefore, have online_pages > 0.
Remove that special handling.
Link: http://lkml.kernel.org/r/20190814154109.3448-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit a9cd410a3d ("mm/page_alloc.c: memory hotplug: free pages as
higher order") assumed that any PFN we get via memory resources is aligned
to to MAX_ORDER - 1, I am not convinced that is always true. Let's play
safe, check the alignment and fallback to single pages.
akpm: warn in this situation so we get to find out if and why this ever
occurs.
[akpm@linux-foundation.org: add WARN_ON_ONCE()]
Link: http://lkml.kernel.org/r/20190814154109.3448-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
online_pages always corresponds to nr_pages. Simplify the code, getting
rid of online_pages_blocks(). Add some comments.
Link: http://lkml.kernel.org/r/20190814154109.3448-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
move_pfn_range_to_zone() will set all pages to PG_reserved via
memmap_init_zone(). The only way a page could no longer be reserved would
be if a MEM_GOING_ONLINE notifier would clear PG_reserved - which is not
done (the online_page callback is used for that purpose by e.g., Hyper-V
instead). walk_system_ram_range() will never call online_pages_range()
with duplicate PFNs, so drop the PageReserved() check.
This seems to be a leftover from ancient times where the memmap was
initialized when adding memory and we wanted to check for already onlined
memory.
Link: http://lkml.kernel.org/r/20190814154109.3448-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Nadav Amit <namit@vmware.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When offlining a node in try_offline_node(), pgdat is not released. So
that pgdat could be reused in hotadd_new_pgdat(). While we reallocate
pgdat->per_cpu_nodestats if this pgdat is reused.
This patch prevents the memory leak by just allocating per_cpu_nodestats
when it is a new pgdat.
Link: http://lkml.kernel.org/r/20190813020608.10194-1-richardw.yang@linux.intel.com
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <OSalvador@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Each memory block spans the same amount of sections/pages/bytes. The size
is determined before the first memory block is created. No need to store
what we can easily calculate - and the calculations even look simpler now.
Michal brought up the idea of variable-sized memory blocks. However, if
we ever implement something like this, we will need an API compatibility
switch and reworks at various places (most code assumes a fixed memory
block size). So let's cleanup what we have right now.
While at it, fix the variable naming in register_mem_sect_under_node() -
we no longer talk about a single section.
Link: http://lkml.kernel.org/r/20190809110200.2746-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let's remove this indirection. We need the zone in the caller either way,
so let's just detect it there. Add some documentation for
move_pfn_range_to_zone() instead.
[akpm@linux-foundation.org: restore newline, per David]
Link: http://lkml.kernel.org/r/20190724142324.3686-1-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using %px to show the actual address in print_bad_pte()
to help us to debug issue.
Link: http://lkml.kernel.org/r/20190831011816.141002-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: remove quicklist page table caches".
A while ago Nicholas proposed to remove quicklist page table caches [1].
I've rebased his patch on the curren upstream and switched ia64 and sh to
use generic versions of PTE allocation.
[1] https://lore.kernel.org/linux-mm/20190711030339.20892-1-npiggin@gmail.com
This patch (of 3):
Remove page table allocator "quicklists". These have been around for a
long time, but have not got much traction in the last decade and are only
used on ia64 and sh architectures.
The numbers in the initial commit look interesting but probably don't
apply anymore. If anybody wants to resurrect this it's in the git
history, but it's unhelpful to have this code and divergent allocator
behaviour for minor archs.
Also it might be better to instead make more general improvements to page
allocator if this is still so slow.
Link: http://lkml.kernel.org/r/1565250728-21721-2-git-send-email-rppt@linux.ibm.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In our testing (camera recording), Miguel and Wei found
unmap_page_range() takes above 6ms with preemption disabled easily.
When I see that, the reason is it holds page table spinlock during
entire 512 page operation in a PMD. 6.2ms is never trivial for user
experince if RT task couldn't run in the time because it could make
frame drop or glitch audio problem.
I had a time to benchmark it via adding some trace_printk hooks between
pte_offset_map_lock and pte_unmap_unlock in zap_pte_range. The testing
device is 2018 premium mobile device.
I can get 2ms delay rather easily to release 2M(ie, 512 pages) when the
task runs on little core even though it doesn't have any IPI and LRU
lock contention. It's already too heavy.
If I remove activate_page, 35-40% overhead of zap_pte_range is gone so
most of overhead(about 0.7ms) comes from activate_page via
mark_page_accessed. Thus, if there are LRU contention, that 0.7ms could
accumulate up to several ms.
So this patch adds a check for need_resched() in the loop, and a
preemption point if necessary.
Link: http://lkml.kernel.org/r/20190731061440.GC155569@google.com
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Miguel de Dios <migueldedios@google.com>
Reported-by: Wei Wang <wvw@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since ptent will not be changed after previous assignment of entry, it is
not necessary to do the assignment again.
Link: http://lkml.kernel.org/r/20190708082740.21111-1-richardw.yang@linux.intel.com
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Acked-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[11~From: John Hubbard <jhubbard@nvidia.com>
Subject: mm/gup: add make_dirty arg to put_user_pages_dirty_lock()
Patch series "mm/gup: add make_dirty arg to put_user_pages_dirty_lock()",
v3.
There are about 50+ patches in my tree [2], and I'll be sending out the
remaining ones in a few more groups:
* The block/bio related changes (Jerome mostly wrote those, but I've had
to move stuff around extensively, and add a little code)
* mm/ changes
* other subsystem patches
* an RFC that shows the current state of the tracking patch set. That
can only be applied after all call sites are converted, but it's good to
get an early look at it.
This is part a tree-wide conversion, as described in fc1d8e7cca ("mm:
introduce put_user_page*(), placeholder versions").
This patch (of 3):
Provide more capable variation of put_user_pages_dirty_lock(), and delete
put_user_pages_dirty(). This is based on the following:
1. Lots of call sites become simpler if a bool is passed into
put_user_page*(), instead of making the call site choose which
put_user_page*() variant to call.
2. Christoph Hellwig's observation that set_page_dirty_lock() is
usually correct, and set_page_dirty() is usually a bug, or at least
questionable, within a put_user_page*() calling chain.
This leads to the following API choices:
* put_user_pages_dirty_lock(page, npages, make_dirty)
* There is no put_user_pages_dirty(). You have to
hand code that, in the rare case that it's
required.
[jhubbard@nvidia.com: remove unused variable in siw_free_plist()]
Link: http://lkml.kernel.org/r/20190729074306.10368-1-jhubbard@nvidia.com
Link: http://lkml.kernel.org/r/20190724044537.10458-2-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
One of our services observed a high rate of cgroup OOM kills in the
presence of large amounts of clean cache. Debugging showed that the
culprit is the shared cgroup iteration in page reclaim.
Under high allocation concurrency, multiple threads enter reclaim at the
same time. Fearing overreclaim when we first switched from the single
global LRU to cgrouped LRU lists, we introduced a shared iteration state
for reclaim invocations - whether 1 or 20 reclaimers are active
concurrently, we only walk the cgroup tree once: the 1st reclaimer
reclaims the first cgroup, the second the second one etc. With more
reclaimers than cgroups, we start another walk from the top.
This sounded reasonable at the time, but the problem is that reclaim
concurrency doesn't scale with allocation concurrency. As reclaim
concurrency increases, the amount of memory individual reclaimers get to
scan gets smaller and smaller. Individual reclaimers may only see one
cgroup per cycle, and that may not have much reclaimable memory. We see
individual reclaimers declare OOM when there is plenty of reclaimable
memory available in cgroups they didn't visit.
This patch does away with the shared iterator, and every reclaimer is
allowed to scan the full cgroup tree and see all of reclaimable memory,
just like it would on a non-cgrouped system. This way, when OOM is
declared, we know that the reclaimer actually had a chance.
To still maintain fairness in reclaim pressure, disallow cgroup reclaim
from bailing out of the tree walk early. Kswapd and regular direct
reclaim already don't bail, so it's not clear why limit reclaim would have
to, especially since it only walks subtrees to begin with.
This change completely eliminates the OOM kills on our service, while
showing no signs of overreclaim - no increased scan rates, %sys time, or
abrupt free memory spikes. I tested across 100 machines that have 64G of
RAM and host about 300 cgroups each.
[ It's possible overreclaim never was a *practical* issue to begin
with - it was simply a concern we had on the mailing lists at the
time, with no real data to back it up. But we have also added more
bail-out conditions deeper inside reclaim (e.g. the proportional
exit in shrink_node_memcg) since. Regardless, now we have data that
suggests full walks are more reliable and scale just fine. ]
Link: http://lkml.kernel.org/r/20190812192316.13615-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 72f0184c8a ("mm, memcg: remove hotplug locking from try_charge")
introduced css_tryget()/css_put() calls in drain_all_stock(), which are
supposed to protect the target memory cgroup from being released during
the mem_cgroup_is_descendant() call.
However, it's not completely safe. In theory, memcg can go away between
reading stock->cached pointer and calling css_tryget().
This can happen if drain_all_stock() races with drain_local_stock()
performed on the remote cpu as a result of a work, scheduled by the
previous invocation of drain_all_stock().
The race is a bit theoretical and there are few chances to trigger it, but
the current code looks a bit confusing, so it makes sense to fix it
anyway. The code looks like as if css_tryget() and css_put() are used to
protect stocks drainage. It's not necessary because stocked pages are
holding references to the cached cgroup. And it obviously won't work for
works, scheduled on other cpus.
So, let's read the stock->cached pointer and evaluate the memory cgroup
inside a rcu read section, and get rid of css_tryget()/css_put() calls.
Link: http://lkml.kernel.org/r/20190802192241.3253165-1-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We're trying to use memory.high to limit workloads, but have found that
containment can frequently fail completely and cause OOM situations
outside of the cgroup. This happens especially with swap space -- either
when none is configured, or swap is full. These failures often also don't
have enough warning to allow one to react, whether for a human or for a
daemon monitoring PSI.
Here is output from a simple program showing how long it takes in usec
(column 2) to allocate a megabyte of anonymous memory (column 1) when a
cgroup is already beyond its memory high setting, and no swap is
available:
[root@ktst ~]# systemd-run -p MemoryHigh=100M -p MemorySwapMax=1 \
> --wait -t timeout 300 /root/mdf
[...]
95 1035
96 1038
97 1000
98 1036
99 1048
100 1590
101 1968
102 1776
103 1863
104 1757
105 1921
106 1893
107 1760
108 1748
109 1843
110 1716
111 1924
112 1776
113 1831
114 1766
115 1836
116 1588
117 1912
118 1802
119 1857
120 1731
[...]
[System OOM in 2-3 seconds]
The delay does go up extremely marginally past the 100MB memory.high
threshold, as now we spend time scanning before returning to usermode, but
it's nowhere near enough to contain growth. It also doesn't get worse the
more pages you have, since it only considers nr_pages.
The current situation goes against both the expectations of users of
memory.high, and our intentions as cgroup v2 developers. In
cgroup-v2.txt, we claim that we will throttle and only under "extreme
conditions" will memory.high protection be breached. Likewise, cgroup v2
users generally also expect that memory.high should throttle workloads as
they exceed their high threshold. However, as seen above, this isn't
always how it works in practice -- even on banal setups like those with no
swap, or where swap has become exhausted, we can end up with memory.high
being breached and us having no weapons left in our arsenal to combat
runaway growth with, since reclaim is futile.
It's also hard for system monitoring software or users to tell how bad the
situation is, as "high" events for the memcg may in some cases be benign,
and in others be catastrophic. The current status quo is that we fail
containment in a way that doesn't provide any advance warning that things
are about to go horribly wrong (for example, we are about to invoke the
kernel OOM killer).
This patch introduces explicit throttling when reclaim is failing to keep
memcg size contained at the memory.high setting. It does so by applying
an exponential delay curve derived from the memcg's overage compared to
memory.high. In the normal case where the memcg is either below or only
marginally over its memory.high setting, no throttling will be performed.
This composes well with system health monitoring and remediation, as these
allocator delays are factored into PSI's memory pressure calculations.
This both creates a mechanism system administrators or applications
consuming the PSI interface to trivially see that the memcg in question is
struggling and use that to make more reasonable decisions, and permits
them enough time to act. Either of these can act with significantly more
nuance than that we can provide using the system OOM killer.
This is a similar idea to memory.oom_control in cgroup v1 which would put
the cgroup to sleep if the threshold was violated, but it's also
significantly improved as it results in visible memory pressure, and also
doesn't schedule indefinitely, which previously made tracing and other
introspection difficult (ie. it's clamped at 2*HZ per allocation through
MEMCG_MAX_HIGH_DELAY_JIFFIES).
Contrast the previous results with a kernel with this patch:
[root@ktst ~]# systemd-run -p MemoryHigh=100M -p MemorySwapMax=1 \
> --wait -t timeout 300 /root/mdf
[...]
95 1002
96 1000
97 1002
98 1003
99 1000
100 1043
101 84724
102 330628
103 610511
104 1016265
105 1503969
106 2391692
107 2872061
108 3248003
109 4791904
110 5759832
111 6912509
112 8127818
113 9472203
114 12287622
115 12480079
116 14144008
117 15808029
118 16384500
119 16383242
120 16384979
[...]
As you can see, in the normal case, memory allocation takes around 1000
usec. However, as we exceed our memory.high, things start to increase
exponentially, but fairly leniently at first. Our first megabyte over
memory.high takes us 0.16 seconds, then the next is 0.46 seconds, then the
next is almost an entire second. This gets worse until we reach our
eventual 2*HZ clamp per batch, resulting in 16 seconds per megabyte.
However, this is still making forward progress, so permits tracing or
further analysis with programs like GDB.
We use an exponential curve for our delay penalty for a few reasons:
1. We run mem_cgroup_handle_over_high to potentially do reclaim after
we've already performed allocations, which means that temporarily
going over memory.high by a small amount may be perfectly legitimate,
even for compliant workloads. We don't want to unduly penalise such
cases.
2. An exponential curve (as opposed to a static or linear delay) allows
ramping up memory pressure stats more gradually, which can be useful
to work out that you have set memory.high too low, without destroying
application performance entirely.
This patch expands on earlier work by Johannes Weiner. Thanks!
[akpm@linux-foundation.org: fix max() warning]
[akpm@linux-foundation.org: fix __udivdi3 ref on 32-bit]
[akpm@linux-foundation.org: fix it even more]
[chris@chrisdown.name: fix 64-bit divide even more]
Link: http://lkml.kernel.org/r/20190723180700.GA29459@chrisdown.name
Signed-off-by: Chris Down <chris@chrisdown.name>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Transparent Huge Pages are currently stored in i_pages as pointers to
consecutive subpages. This patch changes that to storing consecutive
pointers to the head page in preparation for storing huge pages more
efficiently in i_pages.
Large parts of this are "inspired" by Kirill's patch
https://lore.kernel.org/lkml/20170126115819.58875-2-kirill.shutemov@linux.intel.com/
Kirill and Huang Ying contributed several fixes.
[willy@infradead.org: use compound_nr, squish uninit-var warning]
Link: http://lkml.kernel.org/r/20190731210400.7419-1-willy@infradead.org
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Acked-by: Jan Kara <jack@suse.cz>
Reviewed-by: Kirill Shutemov <kirill@shutemov.name>
Reviewed-by: Song Liu <songliubraving@fb.com>
Tested-by: Song Liu <songliubraving@fb.com>
Tested-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Tested-by: Qian Cai <cai@lca.pw>
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This actually checks that writeback is needed or in progress.
Link: http://lkml.kernel.org/r/156378817069.1087.1302816672037672488.stgit@buzz
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Functions like filemap_write_and_wait_range() should do nothing if inode
has no dirty pages or pages currently under writeback. But they anyway
construct struct writeback_control and this does some atomic operations if
CONFIG_CGROUP_WRITEBACK=y - on fast path it locks inode->i_lock and
updates state of writeback ownership, on slow path might be more work.
Current this path is safely avoided only when inode mapping has no pages.
For example generic_file_read_iter() calls filemap_write_and_wait_range()
at each O_DIRECT read - pretty hot path.
This patch skips starting new writeback if mapping has no dirty tags set.
If writeback is already in progress filemap_write_and_wait_range() will
wait for it.
Link: http://lkml.kernel.org/r/156378816804.1087.8607636317907921438.stgit@buzz
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The debug_pagealloc functionality is useful to catch buggy page allocator
users that cause e.g. use after free or double free. When page
inconsistency is detected, debugging is often simpler by knowing the call
stack of process that last allocated and freed the page. When page_owner
is also enabled, we record the allocation stack trace, but not freeing.
This patch therefore adds recording of freeing process stack trace to page
owner info, if both page_owner and debug_pagealloc are configured and
enabled. With only page_owner enabled, this info is not useful for the
memory leak debugging use case. dump_page() is adjusted to print the
info. An example result of calling __free_pages() twice may look like
this (note the page last free stack trace):
BUG: Bad page state in process bash pfn:13d8f8
page:ffffc31984f63e00 refcount:-1 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x1affff800000000()
raw: 01affff800000000 dead000000000100 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 ffffffffffffffff 0000000000000000
page dumped because: nonzero _refcount
page_owner tracks the page as freed
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xcc0(GFP_KERNEL)
prep_new_page+0x143/0x150
get_page_from_freelist+0x289/0x380
__alloc_pages_nodemask+0x13c/0x2d0
khugepaged+0x6e/0xc10
kthread+0xf9/0x130
ret_from_fork+0x3a/0x50
page last free stack trace:
free_pcp_prepare+0x134/0x1e0
free_unref_page+0x18/0x90
khugepaged+0x7b/0xc10
kthread+0xf9/0x130
ret_from_fork+0x3a/0x50
Modules linked in:
CPU: 3 PID: 271 Comm: bash Not tainted 5.3.0-rc4-2.g07a1a73-default+ #57
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014
Call Trace:
dump_stack+0x85/0xc0
bad_page.cold+0xba/0xbf
rmqueue_pcplist.isra.0+0x6c5/0x6d0
rmqueue+0x2d/0x810
get_page_from_freelist+0x191/0x380
__alloc_pages_nodemask+0x13c/0x2d0
__get_free_pages+0xd/0x30
__pud_alloc+0x2c/0x110
copy_page_range+0x4f9/0x630
dup_mmap+0x362/0x480
dup_mm+0x68/0x110
copy_process+0x19e1/0x1b40
_do_fork+0x73/0x310
__x64_sys_clone+0x75/0x80
do_syscall_64+0x6e/0x1e0
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f10af854a10
...
Link: http://lkml.kernel.org/r/20190820131828.22684-5-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For debugging purposes it might be useful to keep the owner info even
after page has been freed, and include it in e.g. dump_page() when
detecting a bad page state. For that, change the PAGE_EXT_OWNER flag
meaning to "page owner info has been set at least once" and add new
PAGE_EXT_OWNER_ACTIVE for tracking whether page is supposed to be
currently tracked allocated or free. Adjust dump_page() accordingly,
distinguishing free and allocated pages. In the page_owner debugfs file,
keep printing only allocated pages so that existing scripts are not
confused, and also because free pages are irrelevant for the memory
statistics or leak detection that's the typical use case of the file,
anyway.
Link: http://lkml.kernel.org/r/20190820131828.22684-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "debug_pagealloc improvements through page_owner", v2.
The debug_pagealloc functionality serves a similar purpose on the page
allocator level that slub_debug does on the kmalloc level, which is to
detect bad users. One notable feature that slub_debug has is storing
stack traces of who last allocated and freed the object. On page level we
track allocations via page_owner, but that info is discarded when freeing,
and we don't track freeing at all. This series improves those aspects.
With both debug_pagealloc and page_owner enabled, we can then get bug
reports such as the example in Patch 4.
SLUB debug tracking additionally stores cpu, pid and timestamp. This could
be added later, if deemed useful enough to justify the additional page_ext
structure size.
This patch (of 3):
Currently, page owner info is only recorded for the first page of a
high-order allocation, and copied to tail pages in the event of a split
page. With the plan to keep previous owner info after freeing the page,
it would be benefical to record page owner for each subpage upon
allocation. This increases the overhead for high orders, but that should
be acceptable for a debugging option.
The order stored for each subpage is the order of the whole allocation.
This makes it possible to calculate the "head" pfn and to recognize "tail"
pages (quoted because not all high-order allocations are compound pages
with true head and tail pages). When reading the page_owner debugfs file,
keep skipping the "tail" pages so that stats gathered by existing scripts
don't get inflated.
Link: http://lkml.kernel.org/r/20190820131828.22684-3-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a cleanup patch that replaces two historical uses of
list_move_tail() with relatively recent add_page_to_lru_list_tail().
Link: http://lkml.kernel.org/r/20190716212436.7137-1-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace 1 << compound_order(page) with compound_nr(page). Minor
improvements in readability.
Link: http://lkml.kernel.org/r/20190721104612.19120-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "Make working with compound pages easier", v2.
These three patches add three helpers and convert the appropriate
places to use them.
This patch (of 3):
It's unnecessarily hard to find out the size of a potentially huge page.
Replace 'PAGE_SIZE << compound_order(page)' with page_size(page).
Link: http://lkml.kernel.org/r/20190721104612.19120-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes gcc '-Wunused-but-set-variable' warning:
mm/rmap.c: In function page_mkclean_one:
mm/rmap.c:906:17: warning: variable cstart set but not used [-Wunused-but-set-variable]
It is not used any more since
commit cdb07bdea2 ("mm/rmap.c: remove redundant variable cend")
Link: http://lkml.kernel.org/r/20190724141453.38536-1-yuehaibing@huawei.com
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add memory corruption identification at bug report for software tag-based
mode. The report shows whether it is "use-after-free" or "out-of-bound"
error instead of "invalid-access" error. This will make it easier for
programmers to see the memory corruption problem.
We extend the slab to store five old free pointer tag and free backtrace,
we can check if the tagged address is in the slab record and make a good
guess if the object is more like "use-after-free" or "out-of-bound".
therefore every slab memory corruption can be identified whether it's
"use-after-free" or "out-of-bound".
[aryabinin@virtuozzo.com: simplify & clenup code]
Link: https://lkml.kernel.org/r/3318f9d7-a760-3cc8-b700-f06108ae745f@virtuozzo.com]
Link: http://lkml.kernel.org/r/20190821180332.11450-1-aryabinin@virtuozzo.com
Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Acked-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The only way to obtain the current memory pool size for a running kernel
is to check the kernel config file which is inconvenient. Record it in
the kernel messages.
[akpm@linux-foundation.org: s/memory pool size/memory pool/available/, per Catalin]
Link: http://lkml.kernel.org/r/1565809631-28933-1-git-send-email-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently kmemleak uses a static early_log buffer to trace all memory
allocation/freeing before the slab allocator is initialised. Such early
log is replayed during kmemleak_init() to properly initialise the kmemleak
metadata for objects allocated up that point. With a memory pool that
does not rely on the slab allocator, it is possible to skip this early log
entirely.
In order to remove the early logging, consider kmemleak_enabled == 1 by
default while the kmem_cache availability is checked directly on the
object_cache and scan_area_cache variables. The RCU callback is only
invoked after object_cache has been initialised as we wouldn't have any
concurrent list traversal before this.
In order to reduce the number of callbacks before kmemleak is fully
initialised, move the kmemleak_init() call to mm_init().
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: remove WARN_ON(), per Catalin]
Link: http://lkml.kernel.org/r/20190812160642.52134-4-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a memory pool for struct kmemleak_object in case the normal
kmem_cache_alloc() fails under the gfp constraints passed by the caller.
The mem_pool[] array size is currently fixed at 16000.
We are not using the existing mempool kernel API since this requires
the slab allocator to be available (for pool->elements allocation). A
subsequent kmemleak patch will replace the static early log buffer with
the pool allocation introduced here and this functionality is required
to be available before the slab was initialised.
Link: http://lkml.kernel.org/r/20190812160642.52134-3-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: kmemleak: Use a memory pool for kmemleak object
allocations", v3.
Following the discussions on v2 of this patch(set) [1], this series takes
slightly different approach:
- it implements its own simple memory pool that does not rely on the
slab allocator
- drops the early log buffer logic entirely since it can now allocate
metadata from the memory pool directly before kmemleak is fully
initialised
- CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE option is renamed to
CONFIG_DEBUG_KMEMLEAK_MEM_POOL_SIZE
- moves the kmemleak_init() call earlier (mm_init())
- to avoid a separate memory pool for struct scan_area, it makes the
tool robust when such allocations fail as scan areas are rather an
optimisation
[1] http://lkml.kernel.org/r/20190727132334.9184-1-catalin.marinas@arm.com
This patch (of 3):
Object scan areas are an optimisation aimed to decrease the false
positives and slightly improve the scanning time of large objects known to
only have a few specific pointers. If a struct scan_area fails to
allocate, kmemleak can still function normally by scanning the full
object.
Introduce an OBJECT_FULL_SCAN flag and mark objects as such when scan_area
allocation fails.
Link: http://lkml.kernel.org/r/20190812160642.52134-2-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
tid_to_cpu() and tid_to_event() are only used in note_cmpxchg_failure()
when SLUB_DEBUG_CMPXCHG=y, so when SLUB_DEBUG_CMPXCHG=n by default, Clang
will complain that those unused functions.
Link: http://lkml.kernel.org/r/1568752232-5094-1-git-send-email-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The memcg_cache_params structure is only embedded into the kmem_cache of
slab and slub allocators as defined in slab_def.h and slub_def.h and used
internally by mm code. There is no needed to expose it in a public
header. So move it from include/linux/slab.h to mm/slab.h. It is just a
refactoring patch with no code change.
In fact both the slub_def.h and slab_def.h should be moved into the mm
directory as well, but that will probably cause many merge conflicts.
Link: http://lkml.kernel.org/r/20190718180827.18758-1-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, a value of '1" is written to /sys/kernel/slab/<slab>/shrink
file to shrink the slab by flushing out all the per-cpu slabs and free
slabs in partial lists. This can be useful to squeeze out a bit more
memory under extreme condition as well as making the active object counts
in /proc/slabinfo more accurate.
This usually applies only to the root caches, as the SLUB_MEMCG_SYSFS_ON
option is usually not enabled and "slub_memcg_sysfs=1" not set. Even if
memcg sysfs is turned on, it is too cumbersome and impractical to manage
all those per-memcg sysfs files in a real production system.
So there is no practical way to shrink memcg caches. Fix this by enabling
a proper write to the shrink sysfs file of the root cache to scan all the
available memcg caches and shrink them as well. For a non-root memcg
cache (when SLUB_MEMCG_SYSFS_ON or slub_memcg_sysfs is on), only that
cache will be shrunk when written.
On a 2-socket 64-core 256-thread arm64 system with 64k page after
a parallel kernel build, the the amount of memory occupied by slabs
before shrinking slabs were:
# grep task_struct /proc/slabinfo
task_struct 53137 53192 4288 61 4 : tunables 0 0
0 : slabdata 872 872 0
# grep "^S[lRU]" /proc/meminfo
Slab: 3936832 kB
SReclaimable: 399104 kB
SUnreclaim: 3537728 kB
After shrinking slabs (by echoing "1" to all shrink files):
# grep "^S[lRU]" /proc/meminfo
Slab: 1356288 kB
SReclaimable: 263296 kB
SUnreclaim: 1092992 kB
# grep task_struct /proc/slabinfo
task_struct 2764 6832 4288 61 4 : tunables 0 0
0 : slabdata 112 112 0
Link: http://lkml.kernel.org/r/20190723151445.7385-1-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
z3fold_page_reclaim()'s retry mechanism is broken: on a second iteration
it will have zhdr from the first one so that zhdr is no longer in line
with struct page. That leads to crashes when the system is stressed.
Fix that by moving zhdr assignment up.
While at it, protect against using already freed handles by using own
local slots structure in z3fold_page_reclaim().
Link: http://lkml.kernel.org/r/20190908162919.830388dc7404d1e2c80f4095@gmail.com
Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Reported-by: Markus Linnala <markus.linnala@gmail.com>
Reported-by: Chris Murphy <bugzilla@colorremedies.com>
Reported-by: Agustin Dall'Alba <agustin@dallalba.com.ar>
Cc: "Maciej S. Szmigiero" <mail@maciej.szmigiero.name>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With the original commit applied, z3fold_zpool_destroy() may get blocked
on wait_event() for indefinite time. Revert this commit for the time
being to get rid of this problem since the issue the original commit
addresses is less severe.
Link: http://lkml.kernel.org/r/20190910123142.7a9c8d2de4d0acbc0977c602@gmail.com
Fixes: d776aaa989 ("mm/z3fold.c: fix race between migration and destruction")
Reported-by: Agustín Dall'Alba <agustin@dallalba.com.ar>
Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Jonathan Adams <jwadams@google.com>
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is more cleanup and consolidation of the hmm APIs and the very
strongly related mmu_notifier interfaces. Many places across the tree
using these interfaces are touched in the process. Beyond that a cleanup
to the page walker API and a few memremap related changes round out the
series:
- General improvement of hmm_range_fault() and related APIs, more
documentation, bug fixes from testing, API simplification &
consolidation, and unused API removal
- Simplify the hmm related kconfigs to HMM_MIRROR and DEVICE_PRIVATE, and
make them internal kconfig selects
- Hoist a lot of code related to mmu notifier attachment out of drivers by
using a refcount get/put attachment idiom and remove the convoluted
mmu_notifier_unregister_no_release() and related APIs.
- General API improvement for the migrate_vma API and revision of its only
user in nouveau
- Annotate mmu_notifiers with lockdep and sleeping region debugging
Two series unrelated to HMM or mmu_notifiers came along due to
dependencies:
- Allow pagemap's memremap_pages family of APIs to work without providing
a struct device
- Make walk_page_range() and related use a constant structure for function
pointers
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Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull hmm updates from Jason Gunthorpe:
"This is more cleanup and consolidation of the hmm APIs and the very
strongly related mmu_notifier interfaces. Many places across the tree
using these interfaces are touched in the process. Beyond that a
cleanup to the page walker API and a few memremap related changes
round out the series:
- General improvement of hmm_range_fault() and related APIs, more
documentation, bug fixes from testing, API simplification &
consolidation, and unused API removal
- Simplify the hmm related kconfigs to HMM_MIRROR and DEVICE_PRIVATE,
and make them internal kconfig selects
- Hoist a lot of code related to mmu notifier attachment out of
drivers by using a refcount get/put attachment idiom and remove the
convoluted mmu_notifier_unregister_no_release() and related APIs.
- General API improvement for the migrate_vma API and revision of its
only user in nouveau
- Annotate mmu_notifiers with lockdep and sleeping region debugging
Two series unrelated to HMM or mmu_notifiers came along due to
dependencies:
- Allow pagemap's memremap_pages family of APIs to work without
providing a struct device
- Make walk_page_range() and related use a constant structure for
function pointers"
* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (75 commits)
libnvdimm: Enable unit test infrastructure compile checks
mm, notifier: Catch sleeping/blocking for !blockable
kernel.h: Add non_block_start/end()
drm/radeon: guard against calling an unpaired radeon_mn_unregister()
csky: add missing brackets in a macro for tlb.h
pagewalk: use lockdep_assert_held for locking validation
pagewalk: separate function pointers from iterator data
mm: split out a new pagewalk.h header from mm.h
mm/mmu_notifiers: annotate with might_sleep()
mm/mmu_notifiers: prime lockdep
mm/mmu_notifiers: add a lockdep map for invalidate_range_start/end
mm/mmu_notifiers: remove the __mmu_notifier_invalidate_range_start/end exports
mm/hmm: hmm_range_fault() infinite loop
mm/hmm: hmm_range_fault() NULL pointer bug
mm/hmm: fix hmm_range_fault()'s handling of swapped out pages
mm/mmu_notifiers: remove unregister_no_release
RDMA/odp: remove ib_ucontext from ib_umem
RDMA/odp: use mmu_notifier_get/put for 'struct ib_ucontext_per_mm'
RDMA/mlx5: Use odp instead of mr->umem in pagefault_mr
RDMA/mlx5: Use ib_umem_start instead of umem.address
...
- add dma-mapping and block layer helpers to take care of IOMMU
merging for mmc plus subsequent fixups (Yoshihiro Shimoda)
- rework handling of the pgprot bits for remapping (me)
- take care of the dma direct infrastructure for swiotlb-xen (me)
- improve the dma noncoherent remapping infrastructure (me)
- better defaults for ->mmap, ->get_sgtable and ->get_required_mask (me)
- cleanup mmaping of coherent DMA allocations (me)
- various misc cleanups (Andy Shevchenko, me)
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Merge tag 'dma-mapping-5.4' of git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping updates from Christoph Hellwig:
- add dma-mapping and block layer helpers to take care of IOMMU merging
for mmc plus subsequent fixups (Yoshihiro Shimoda)
- rework handling of the pgprot bits for remapping (me)
- take care of the dma direct infrastructure for swiotlb-xen (me)
- improve the dma noncoherent remapping infrastructure (me)
- better defaults for ->mmap, ->get_sgtable and ->get_required_mask
(me)
- cleanup mmaping of coherent DMA allocations (me)
- various misc cleanups (Andy Shevchenko, me)
* tag 'dma-mapping-5.4' of git://git.infradead.org/users/hch/dma-mapping: (41 commits)
mmc: renesas_sdhi_internal_dmac: Add MMC_CAP2_MERGE_CAPABLE
mmc: queue: Fix bigger segments usage
arm64: use asm-generic/dma-mapping.h
swiotlb-xen: merge xen_unmap_single into xen_swiotlb_unmap_page
swiotlb-xen: simplify cache maintainance
swiotlb-xen: use the same foreign page check everywhere
swiotlb-xen: remove xen_swiotlb_dma_mmap and xen_swiotlb_dma_get_sgtable
xen: remove the exports for xen_{create,destroy}_contiguous_region
xen/arm: remove xen_dma_ops
xen/arm: simplify dma_cache_maint
xen/arm: use dev_is_dma_coherent
xen/arm: consolidate page-coherent.h
xen/arm: use dma-noncoherent.h calls for xen-swiotlb cache maintainance
arm: remove wrappers for the generic dma remap helpers
dma-mapping: introduce a dma_common_find_pages helper
dma-mapping: always use VM_DMA_COHERENT for generic DMA remap
vmalloc: lift the arm flag for coherent mappings to common code
dma-mapping: provide a better default ->get_required_mask
dma-mapping: remove the dma_declare_coherent_memory export
remoteproc: don't allow modular build
...
Pull misc mount API conversions from Al Viro:
"Conversions to new API for shmem and friends and for mount_mtd()-using
filesystems.
As for the rest of the mount API conversions in -next, some of them
belong in the individual trees (e.g. binderfs one should definitely go
through android folks, after getting redone on top of their changes).
I'm going to drop those and send the rest (trivial ones + stuff ACKed
by maintainers) in a separate series - by that point they are
independent from each other.
Some stuff has already migrated into individual trees (NFS conversion,
for example, or FUSE stuff, etc.); those presumably will go through
the regular merges from corresponding trees."
* 'work.mount2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vfs: Make fs_parse() handle fs_param_is_fd-type params better
vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API
shmem_parse_one(): switch to use of fs_parse()
shmem_parse_options(): take handling a single option into a helper
shmem_parse_options(): don't bother with mpol in separate variable
shmem_parse_options(): use a separate structure to keep the results
make shmem_fill_super() static
make ramfs_fill_super() static
devtmpfs: don't mix {ramfs,shmem}_fill_super() with mount_single()
vfs: Convert squashfs to use the new mount API
mtd: Kill mount_mtd()
vfs: Convert jffs2 to use the new mount API
vfs: Convert cramfs to use the new mount API
vfs: Convert romfs to use the new mount API
vfs: Add a single-or-reconfig keying to vfs_get_super()
- Remove KM_SLEEP/KM_NOSLEEP.
- Ensure that memory buffers for IO are properly sector-aligned to avoid
problems that the block layer doesn't check.
- Make the bmap scrubber more efficient in its record checking.
- Don't crash xfs_db when superblock inode geometry is corrupt.
- Fix btree key helper functions.
- Remove unneeded error returns for things that can't fail.
- Fix buffer logging bugs in repair.
- Clean up iterator return values.
- Speed up directory entry creation.
- Enable allocation of xattr value memory buffer during lookup.
- Fix readahead racing with truncate/punch hole.
- Other minor cleanups.
- Fix one AGI/AGF deadlock with RENAME_WHITEOUT.
- More BUG -> WARN whackamole.
- Fix various problems with the log failing to advance under certain
circumstances, which results in stalls during mount.
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Merge tag 'xfs-5.4-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs updates from Darrick Wong:
"For this cycle we have the usual pile of cleanups and bug fixes, some
performance improvements for online metadata scrubbing, massive
speedups in the directory entry creation code, some performance
improvement in the file ACL lookup code, a fix for a logging stall
during mount, and fixes for concurrency problems.
It has survived a couple of weeks of xfstests runs and merges cleanly.
Summary:
- Remove KM_SLEEP/KM_NOSLEEP.
- Ensure that memory buffers for IO are properly sector-aligned to
avoid problems that the block layer doesn't check.
- Make the bmap scrubber more efficient in its record checking.
- Don't crash xfs_db when superblock inode geometry is corrupt.
- Fix btree key helper functions.
- Remove unneeded error returns for things that can't fail.
- Fix buffer logging bugs in repair.
- Clean up iterator return values.
- Speed up directory entry creation.
- Enable allocation of xattr value memory buffer during lookup.
- Fix readahead racing with truncate/punch hole.
- Other minor cleanups.
- Fix one AGI/AGF deadlock with RENAME_WHITEOUT.
- More BUG -> WARN whackamole.
- Fix various problems with the log failing to advance under certain
circumstances, which results in stalls during mount"
* tag 'xfs-5.4-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (45 commits)
xfs: push the grant head when the log head moves forward
xfs: push iclog state cleaning into xlog_state_clean_log
xfs: factor iclog state processing out of xlog_state_do_callback()
xfs: factor callbacks out of xlog_state_do_callback()
xfs: factor debug code out of xlog_state_do_callback()
xfs: prevent CIL push holdoff in log recovery
xfs: fix missed wakeup on l_flush_wait
xfs: push the AIL in xlog_grant_head_wake
xfs: Use WARN_ON_ONCE for bailout mount-operation
xfs: Fix deadlock between AGI and AGF with RENAME_WHITEOUT
xfs: define a flags field for the AG geometry ioctl structure
xfs: add a xfs_valid_startblock helper
xfs: remove the unused XFS_ALLOC_USERDATA flag
xfs: cleanup xfs_fsb_to_db
xfs: fix the dax supported check in xfs_ioctl_setattr_dax_invalidate
xfs: Fix stale data exposure when readahead races with hole punch
fs: Export generic_fadvise()
mm: Handle MADV_WILLNEED through vfs_fadvise()
xfs: allocate xattr buffer on demand
xfs: consolidate attribute value copying
...
- Prohibit writing to active swap files and swap partitions.
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Merge tag 'vfs-5.4-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull swap access updates from Darrick Wong:
"Prohibit writing to active swap files and swap partitions.
There's no non-malicious use case for allowing userspace to scribble
on storage that the kernel thinks it owns"
* tag 'vfs-5.4-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
vfs: don't allow writes to swap files
mm: set S_SWAPFILE on blockdev swap devices
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Merge tag 'for-5.4/block-2019-09-16' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
- Two NVMe pull requests:
- ana log parse fix from Anton
- nvme quirks support for Apple devices from Ben
- fix missing bio completion tracing for multipath stack devices
from Hannes and Mikhail
- IP TOS settings for nvme rdma and tcp transports from Israel
- rq_dma_dir cleanups from Israel
- tracing for Get LBA Status command from Minwoo
- Some nvme-tcp cleanups from Minwoo, Potnuri and Myself
- Some consolidation between the fabrics transports for handling
the CAP register
- reset race with ns scanning fix for fabrics (move fabrics
commands to a dedicated request queue with a different lifetime
from the admin request queue)."
- controller reset and namespace scan races fixes
- nvme discovery log change uevent support
- naming improvements from Keith
- multiple discovery controllers reject fix from James
- some regular cleanups from various people
- Series fixing (and re-fixing) null_blk debug printing and nr_devices
checks (André)
- A few pull requests from Song, with fixes from Andy, Guoqing,
Guilherme, Neil, Nigel, and Yufen.
- REQ_OP_ZONE_RESET_ALL support (Chaitanya)
- Bio merge handling unification (Christoph)
- Pick default elevator correctly for devices with special needs
(Damien)
- Block stats fixes (Hou)
- Timeout and support devices nbd fixes (Mike)
- Series fixing races around elevator switching and device add/remove
(Ming)
- sed-opal cleanups (Revanth)
- Per device weight support for BFQ (Fam)
- Support for blk-iocost, a new model that can properly account cost of
IO workloads. (Tejun)
- blk-cgroup writeback fixes (Tejun)
- paride queue init fixes (zhengbin)
- blk_set_runtime_active() cleanup (Stanley)
- Block segment mapping optimizations (Bart)
- lightnvm fixes (Hans/Minwoo/YueHaibing)
- Various little fixes and cleanups
* tag 'for-5.4/block-2019-09-16' of git://git.kernel.dk/linux-block: (186 commits)
null_blk: format pr_* logs with pr_fmt
null_blk: match the type of parameter nr_devices
null_blk: do not fail the module load with zero devices
block: also check RQF_STATS in blk_mq_need_time_stamp()
block: make rq sector size accessible for block stats
bfq: Fix bfq linkage error
raid5: use bio_end_sector in r5_next_bio
raid5: remove STRIPE_OPS_REQ_PENDING
md: add feature flag MD_FEATURE_RAID0_LAYOUT
md/raid0: avoid RAID0 data corruption due to layout confusion.
raid5: don't set STRIPE_HANDLE to stripe which is in batch list
raid5: don't increment read_errors on EILSEQ return
nvmet: fix a wrong error status returned in error log page
nvme: send discovery log page change events to userspace
nvme: add uevent variables for controller devices
nvme: enable aen regardless of the presence of I/O queues
nvme-fabrics: allow discovery subsystems accept a kato
nvmet: Use PTR_ERR_OR_ZERO() in nvmet_init_discovery()
nvme: Remove redundant assignment of cq vector
nvme: Assign subsys instance from first ctrl
...
Pull percpu updates from Dennis Zhou:
"A couple of updates to clean up the code with no change in behavior"
* 'for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu:
percpu: Use struct_size() helper
percpu: fix typo in pcpu_setup_first_chunk() comment
percpu: Make pcpu_setup_first_chunk() void function
When running on a system with >512MB RAM with a 32-bit kernel built with:
CONFIG_DEBUG_VIRTUAL=y
CONFIG_HIGHMEM=y
CONFIG_HARDENED_USERCOPY=y
all execve()s will fail due to argv copying into kmap()ed pages, and on
usercopy checking the calls ultimately of virt_to_page() will be looking
for "bad" kmap (highmem) pointers due to CONFIG_DEBUG_VIRTUAL=y:
------------[ cut here ]------------
kernel BUG at ../arch/x86/mm/physaddr.c:83!
invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.3.0-rc8 #6
Hardware name: Dell Inc. Inspiron 1318/0C236D, BIOS A04 01/15/2009
EIP: __phys_addr+0xaf/0x100
...
Call Trace:
__check_object_size+0xaf/0x3c0
? __might_sleep+0x80/0xa0
copy_strings+0x1c2/0x370
copy_strings_kernel+0x2b/0x40
__do_execve_file+0x4ca/0x810
? kmem_cache_alloc+0x1c7/0x370
do_execve+0x1b/0x20
...
The check is from arch/x86/mm/physaddr.c:
VIRTUAL_BUG_ON((phys_addr >> PAGE_SHIFT) > max_low_pfn);
Due to the kmap() in fs/exec.c:
kaddr = kmap(kmapped_page);
...
if (copy_from_user(kaddr+offset, str, bytes_to_copy)) ...
Now we can fetch the correct page to avoid the pfn check. In both cases,
hardened usercopy will need to walk the page-span checker (if enabled)
to do sanity checking.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Fixes: f5509cc18d ("mm: Hardened usercopy")
Cc: Matthew Wilcox <willy@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/201909171056.7F2FFD17@keescook
Pull scheduler updates from Ingo Molnar:
- MAINTAINERS: Add Mark Rutland as perf submaintainer, Juri Lelli and
Vincent Guittot as scheduler submaintainers. Add Dietmar Eggemann,
Steven Rostedt, Ben Segall and Mel Gorman as scheduler reviewers.
As perf and the scheduler is getting bigger and more complex,
document the status quo of current responsibilities and interests,
and spread the review pain^H^H^H^H fun via an increase in the Cc:
linecount generated by scripts/get_maintainer.pl. :-)
- Add another series of patches that brings the -rt (PREEMPT_RT) tree
closer to mainline: split the monolithic CONFIG_PREEMPT dependencies
into a new CONFIG_PREEMPTION category that will allow the eventual
introduction of CONFIG_PREEMPT_RT. Still a few more hundred patches
to go though.
- Extend the CPU cgroup controller with uclamp.min and uclamp.max to
allow the finer shaping of CPU bandwidth usage.
- Micro-optimize energy-aware wake-ups from O(CPUS^2) to O(CPUS).
- Improve the behavior of high CPU count, high thread count
applications running under cpu.cfs_quota_us constraints.
- Improve balancing with SCHED_IDLE (SCHED_BATCH) tasks present.
- Improve CPU isolation housekeeping CPU allocation NUMA locality.
- Fix deadline scheduler bandwidth calculations and logic when cpusets
rebuilds the topology, or when it gets deadline-throttled while it's
being offlined.
- Convert the cpuset_mutex to percpu_rwsem, to allow it to be used from
setscheduler() system calls without creating global serialization.
Add new synchronization between cpuset topology-changing events and
the deadline acceptance tests in setscheduler(), which were broken
before.
- Rework the active_mm state machine to be less confusing and more
optimal.
- Rework (simplify) the pick_next_task() slowpath.
- Improve load-balancing on AMD EPYC systems.
- ... and misc cleanups, smaller fixes and improvements - please see
the Git log for more details.
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (53 commits)
sched/psi: Correct overly pessimistic size calculation
sched/fair: Speed-up energy-aware wake-ups
sched/uclamp: Always use 'enum uclamp_id' for clamp_id values
sched/uclamp: Update CPU's refcount on TG's clamp changes
sched/uclamp: Use TG's clamps to restrict TASK's clamps
sched/uclamp: Propagate system defaults to the root group
sched/uclamp: Propagate parent clamps
sched/uclamp: Extend CPU's cgroup controller
sched/topology: Improve load balancing on AMD EPYC systems
arch, ia64: Make NUMA select SMP
sched, perf: MAINTAINERS update, add submaintainers and reviewers
sched/fair: Use rq_lock/unlock in online_fair_sched_group
cpufreq: schedutil: fix equation in comment
sched: Rework pick_next_task() slow-path
sched: Allow put_prev_task() to drop rq->lock
sched/fair: Expose newidle_balance()
sched: Add task_struct pointer to sched_class::set_curr_task
sched: Rework CPU hotplug task selection
sched/{rt,deadline}: Fix set_next_task vs pick_next_task
sched: Fix kerneldoc comment for ia64_set_curr_task
...
Convert the ramfs, shmem, tmpfs, devtmpfs and rootfs filesystems to the new
internal mount API as the old one will be obsoleted and removed. This
allows greater flexibility in communication of mount parameters between
userspace, the VFS and the filesystem.
See Documentation/filesystems/mount_api.txt for more information.
Note that tmpfs is slightly tricky as it can contain embedded commas, so it
can't be trivially split up using strsep() to break on commas in
generic_parse_monolithic(). Instead, tmpfs has to supply its own generic
parser.
However, if tmpfs changes, then devtmpfs and rootfs, which are wrappers
around tmpfs or ramfs, must change too - and thus so must ramfs, so these
had to be converted also.
[AV: rewritten]
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Hugh Dickins <hughd@google.com>
cc: linux-mm@kvack.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This thing will eventually become our ->parse_param(), while
shmem_parse_options() - ->parse_monolithic(). At that point
shmem_parse_options() will start calling vfs_parse_fs_string(),
rather than calling shmem_parse_one() directly.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
... and copy the data from it into sbinfo in the callers.
For use by remount we need to keep track whether there'd
been options setting max_inodes, max_blocks and huge resp.
and do the sanity checks (and copying) only if such options
had been seen. uid/gid/mode is ignored by remount and
NULL mpol is already explicitly treated as "ignore it",
so we don't need to keep track of those.
Note: theoretically, mpol_parse_string() may return NULL
not in case of error (for default policy), so the assumption
that NULL mpol means "change nothing" is incorrect. However,
that's the mainline behaviour and any changes belong in
a separate patch. If we go for that, we'll need to keep
track of having encountered mpol= option too.
[changes in remount logics from Hugh Dickins folded]
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We need to make sure implementations don't cheat and don't have a possible
schedule/blocking point deeply burried where review can't catch it.
I'm not sure whether this is the best way to make sure all the
might_sleep() callsites trigger, and it's a bit ugly in the code flow.
But it gets the job done.
Inspired by an i915 patch series which did exactly that, because the rules
haven't been entirely clear to us.
Link: https://lore.kernel.org/r/20190826201425.17547-5-daniel.vetter@ffwll.ch
Reviewed-by: Christian König <christian.koenig@amd.com> (v1)
Reviewed-by: Jérôme Glisse <jglisse@redhat.com> (v4)
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Use lockdep to check for held locks instead of using home grown asserts.
Link: https://lore.kernel.org/r/20190828141955.22210-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
The mm_walk structure currently mixed data and code. Split out the
operations vectors into a new mm_walk_ops structure, and while we are
changing the API also declare the mm_walk structure inside the
walk_page_range and walk_page_vma functions.
Based on patch from Linus Torvalds.
Link: https://lore.kernel.org/r/20190828141955.22210-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Add a new header for the two handful of users of the walk_page_range /
walk_page_vma interface instead of polluting all users of mm.h with it.
Link: https://lore.kernel.org/r/20190828141955.22210-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
We want to teach lockdep that mmu notifiers can be called from direct
reclaim paths, since on many CI systems load might never reach that
level (e.g. when just running fuzzer or small functional tests).
I've put the annotation into mmu_notifier_register since only when we have
mmu notifiers registered is there any point in teaching lockdep about
them. Also, we already have a kmalloc(, GFP_KERNEL), so this is safe.
Link: https://lore.kernel.org/r/20190826201425.17547-3-daniel.vetter@ffwll.ch
Suggested-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This is a similar idea to the fs_reclaim fake lockdep lock. It's fairly
easy to provoke a specific notifier to be run on a specific range: Just
prep it, and then munmap() it.
A bit harder, but still doable, is to provoke the mmu notifiers for all
the various callchains that might lead to them. But both at the same time
is really hard to reliably hit, especially when you want to exercise paths
like direct reclaim or compaction, where it's not easy to control what
exactly will be unmapped.
By introducing a lockdep map to tie them all together we allow lockdep to
see a lot more dependencies, without having to actually hit them in a
single challchain while testing.
On Jason's suggestion this is is rolled out for both
invalidate_range_start and invalidate_range_end. They both have the same
calling context, hence we can share the same lockdep map. Note that the
annotation for invalidate_ranage_start is outside of the
mm_has_notifiers(), to make sure lockdep is informed about all paths
leading to this context irrespective of whether mmu notifiers are present
for a given context. We don't do that on the invalidate_range_end side to
avoid paying the overhead twice, there the lockdep annotation is pushed
down behind the mm_has_notifiers() check.
Link: https://lore.kernel.org/r/20190826201425.17547-2-daniel.vetter@ffwll.ch
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:
struct pcpu_alloc_info {
...
struct pcpu_group_info groups[];
};
Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.
So, replace the following form:
sizeof(*ai) + nr_groups * sizeof(ai->groups[0])
with:
struct_size(ai, groups, nr_groups)
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
There is no reason to print warnings when balloon page allocation fails,
as they are expected and can be handled gracefully. Since VMware
balloon now uses balloon-compaction infrastructure, and suppressed these
warnings before, it is also beneficial to suppress these warnings to
keep the same behavior that the balloon had before.
Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
The arm architecture had a VM_ARM_DMA_CONSISTENT flag to mark DMA
coherent remapping for a while. Lift this flag to common code so
that we can use it generically. We also check it in the only place
VM_USERMAP is directly check so that we can entirely replace that
flag as well (although I'm not even sure why we'd want to allow
remapping DMA appings, but I'd rather not change behavior).
Signed-off-by: Christoph Hellwig <hch@lst.de>
SD_BALANCE_{FORK,EXEC} and SD_WAKE_AFFINE are stripped in sd_init()
for any sched domains with a NUMA distance greater than 2 hops
(RECLAIM_DISTANCE). The idea being that it's expensive to balance
across domains that far apart.
However, as is rather unfortunately explained in:
commit 32e45ff43e ("mm: increase RECLAIM_DISTANCE to 30")
the value for RECLAIM_DISTANCE is based on node distance tables from
2011-era hardware.
Current AMD EPYC machines have the following NUMA node distances:
node distances:
node 0 1 2 3 4 5 6 7
0: 10 16 16 16 32 32 32 32
1: 16 10 16 16 32 32 32 32
2: 16 16 10 16 32 32 32 32
3: 16 16 16 10 32 32 32 32
4: 32 32 32 32 10 16 16 16
5: 32 32 32 32 16 10 16 16
6: 32 32 32 32 16 16 10 16
7: 32 32 32 32 16 16 16 10
where 2 hops is 32.
The result is that the scheduler fails to load balance properly across
NUMA nodes on different sockets -- 2 hops apart.
For example, pinning 16 busy threads to NUMA nodes 0 (CPUs 0-7) and 4
(CPUs 32-39) like so,
$ numactl -C 0-7,32-39 ./spinner 16
causes all threads to fork and remain on node 0 until the active
balancer kicks in after a few seconds and forcibly moves some threads
to node 4.
Override node_reclaim_distance for AMD Zen.
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Suravee.Suthikulpanit@amd.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas.Lendacky@amd.com
Cc: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/20190808195301.13222-3-matt@codeblueprint.co.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Filesystems will need to call this function from their fadvise handlers.
CC: stable@vger.kernel.org
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Currently handling of MADV_WILLNEED hint calls directly into readahead
code. Handle it by calling vfs_fadvise() instead so that filesystem can
use its ->fadvise() callback to acquire necessary locks or otherwise
prepare for the request.
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Boaz Harrosh <boazh@netapp.com>
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Instead of using raw_cpu_read() use per_cpu() to read the actual data of
the corresponding cpu otherwise we will be reading the data of the
current cpu for the number of online CPUs.
Link: http://lkml.kernel.org/r/20190829203110.129263-1-shakeelb@google.com
Fixes: bb65f89b7d ("mm: memcontrol: flush percpu vmevents before releasing memcg")
Fixes: c350a99ea2 ("mm: memcontrol: flush percpu vmstats before releasing memcg")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Adric Blake has noticed[1] the following warning:
WARNING: CPU: 7 PID: 175 at mm/vmscan.c:245 set_task_reclaim_state+0x1e/0x40
[...]
Call Trace:
mem_cgroup_shrink_node+0x9b/0x1d0
mem_cgroup_soft_limit_reclaim+0x10c/0x3a0
balance_pgdat+0x276/0x540
kswapd+0x200/0x3f0
? wait_woken+0x80/0x80
kthread+0xfd/0x130
? balance_pgdat+0x540/0x540
? kthread_park+0x80/0x80
ret_from_fork+0x35/0x40
---[ end trace 727343df67b2398a ]---
which tells us that soft limit reclaim is about to overwrite the
reclaim_state configured up in the call chain (kswapd in this case but
the direct reclaim is equally possible). This means that reclaim stats
would get misleading once the soft reclaim returns and another reclaim
is done.
Fix the warning by dropping set_task_reclaim_state from the soft reclaim
which is always called with reclaim_state set up.
[1] http://lkml.kernel.org/r/CAE1jjeePxYPvw1mw2B3v803xHVR_BNnz0hQUY_JDMN8ny29M6w@mail.gmail.com
Link: http://lkml.kernel.org/r/20190828071808.20410-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reported-by: Adric Blake <promarbler14@gmail.com>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Yang Shi <yang.shi@linux.alibaba.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hillf Danton <hdanton@sina.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 766a4c19d8 ("mm/memcontrol.c: keep local VM counters in sync
with the hierarchical ones") effectively decreased the precision of
per-memcg vmstats_local and per-memcg-per-node lruvec percpu counters.
That's good for displaying in memory.stat, but brings a serious
regression into the reclaim process.
One issue I've discovered and debugged is the following:
lruvec_lru_size() can return 0 instead of the actual number of pages in
the lru list, preventing the kernel to reclaim last remaining pages.
Result is yet another dying memory cgroups flooding. The opposite is
also happening: scanning an empty lru list is the waste of cpu time.
Also, inactive_list_is_low() can return incorrect values, preventing the
active lru from being scanned and freed. It can fail both because the
size of active and inactive lists are inaccurate, and because the number
of workingset refaults isn't precise. In other words, the result is
pretty random.
I'm not sure, if using the approximate number of slab pages in
count_shadow_number() is acceptable, but issues described above are
enough to partially revert the patch.
Let's keep per-memcg vmstat_local batched (they are only used for
displaying stats to the userspace), but keep lruvec stats precise. This
change fixes the dead memcg flooding on my setup.
Link: http://lkml.kernel.org/r/20190817004726.2530670-1-guro@fb.com
Fixes: 766a4c19d8 ("mm/memcontrol.c: keep local VM counters in sync with the hierarchical ones")
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Yafang Shao <laoar.shao@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I've noticed that the "slab" value in memory.stat is sometimes 0, even
if some children memory cgroups have a non-zero "slab" value. The
following investigation showed that this is the result of the kmem_cache
reparenting in combination with the per-cpu batching of slab vmstats.
At the offlining some vmstat value may leave in the percpu cache, not
being propagated upwards by the cgroup hierarchy. It means that stats
on ancestor levels are lower than actual. Later when slab pages are
released, the precise number of pages is substracted on the parent
level, making the value negative. We don't show negative values, 0 is
printed instead.
To fix this issue, let's flush percpu slab memcg and lruvec stats on
memcg offlining. This guarantees that numbers on all ancestor levels
are accurate and match the actual number of outstanding slab pages.
Link: http://lkml.kernel.org/r/20190819202338.363363-3-guro@fb.com
Fixes: fb2f2b0adb ("mm: memcg/slab: reparent memcg kmem_caches on cgroup removal")
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
cgroup foreign inode handling has quite a bit of heuristics and
internal states which sometimes makes it difficult to understand
what's going on. Add tracepoints to improve visibility.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
No modular code uses these, which makes a lot of sense given the wrappers
around them are only called by core mm code.
Link: https://lore.kernel.org/r/20190828142109.29012-1-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Normally, callers to handle_mm_fault() are supposed to check the
vma->vm_flags first. hmm_range_fault() checks for VM_READ but doesn't
check for VM_WRITE if the caller requests a page to be faulted in with
write permission (via the hmm_range.pfns[] value). If the vma is write
protected, this can result in an infinite loop:
hmm_range_fault()
walk_page_range()
...
hmm_vma_walk_hole()
hmm_vma_walk_hole_()
hmm_vma_do_fault()
handle_mm_fault(FAULT_FLAG_WRITE)
/* returns VM_FAULT_WRITE */
/* returns -EBUSY */
/* returns -EBUSY */
/* returns -EBUSY */
/* loops on -EBUSY and range->valid */
Prevent this by checking for vma->vm_flags & VM_WRITE before calling
handle_mm_fault().
Link: https://lore.kernel.org/r/20190823221753.2514-3-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Although hmm_range_fault() calls find_vma() to make sure that a vma exists
before calling walk_page_range(), hmm_vma_walk_hole() can still be called
with walk->vma == NULL if the start and end address are not contained
within the vma range.
hmm_range_fault() /* calls find_vma() but no range check */
walk_page_range() /* calls find_vma(), sets walk->vma = NULL */
__walk_page_range()
walk_pgd_range()
walk_p4d_range()
walk_pud_range()
hmm_vma_walk_hole()
hmm_vma_walk_hole_()
hmm_vma_do_fault()
handle_mm_fault(vma=0)
Link: https://lore.kernel.org/r/20190823221753.2514-2-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
There's an inherent mismatch between memcg and writeback. The former
trackes ownership per-page while the latter per-inode. This was a
deliberate design decision because honoring per-page ownership in the
writeback path is complicated, may lead to higher CPU and IO overheads
and deemed unnecessary given that write-sharing an inode across
different cgroups isn't a common use-case.
Combined with inode majority-writer ownership switching, this works
well enough in most cases but there are some pathological cases. For
example, let's say there are two cgroups A and B which keep writing to
different but confined parts of the same inode. B owns the inode and
A's memory is limited far below B's. A's dirty ratio can rise enough
to trigger balance_dirty_pages() sleeps but B's can be low enough to
avoid triggering background writeback. A will be slowed down without
a way to make writeback of the dirty pages happen.
This patch implements foreign dirty recording and foreign mechanism so
that when a memcg encounters a condition as above it can trigger
flushes on bdi_writebacks which can clean its pages. Please see the
comment on top of mem_cgroup_track_foreign_dirty_slowpath() for
details.
A reproducer follows.
write-range.c::
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
static const char *usage = "write-range FILE START SIZE\n";
int main(int argc, char **argv)
{
int fd;
unsigned long start, size, end, pos;
char *endp;
char buf[4096];
if (argc < 4) {
fprintf(stderr, usage);
return 1;
}
fd = open(argv[1], O_WRONLY);
if (fd < 0) {
perror("open");
return 1;
}
start = strtoul(argv[2], &endp, 0);
if (*endp != '\0') {
fprintf(stderr, usage);
return 1;
}
size = strtoul(argv[3], &endp, 0);
if (*endp != '\0') {
fprintf(stderr, usage);
return 1;
}
end = start + size;
while (1) {
for (pos = start; pos < end; ) {
long bread, bwritten = 0;
if (lseek(fd, pos, SEEK_SET) < 0) {
perror("lseek");
return 1;
}
bread = read(0, buf, sizeof(buf) < end - pos ?
sizeof(buf) : end - pos);
if (bread < 0) {
perror("read");
return 1;
}
if (bread == 0)
return 0;
while (bwritten < bread) {
long this;
this = write(fd, buf + bwritten,
bread - bwritten);
if (this < 0) {
perror("write");
return 1;
}
bwritten += this;
pos += bwritten;
}
}
}
}
repro.sh::
#!/bin/bash
set -e
set -x
sysctl -w vm.dirty_expire_centisecs=300000
sysctl -w vm.dirty_writeback_centisecs=300000
sysctl -w vm.dirtytime_expire_seconds=300000
echo 3 > /proc/sys/vm/drop_caches
TEST=/sys/fs/cgroup/test
A=$TEST/A
B=$TEST/B
mkdir -p $A $B
echo "+memory +io" > $TEST/cgroup.subtree_control
echo $((1<<30)) > $A/memory.high
echo $((32<<30)) > $B/memory.high
rm -f testfile
touch testfile
fallocate -l 4G testfile
echo "Starting B"
(echo $BASHPID > $B/cgroup.procs
pv -q --rate-limit 70M < /dev/urandom | ./write-range testfile $((2<<30)) $((2<<30))) &
echo "Waiting 10s to ensure B claims the testfile inode"
sleep 5
sync
sleep 5
sync
echo "Starting A"
(echo $BASHPID > $A/cgroup.procs
pv < /dev/urandom | ./write-range testfile 0 $((2<<30)))
v2: Added comments explaining why the specific intervals are being used.
v3: Use 0 @nr when calling cgroup_writeback_by_id() to use best-effort
flushing while avoding possible livelocks.
v4: Use get_jiffies_64() and time_before/after64() instead of raw
jiffies_64 and arthimetic comparisons as suggested by Jan.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Separate out wb_get_lookup() which doesn't try to create one if there
isn't already one from wb_get_create(). This will be used by later
patches.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There currently is no way to universally identify and lookup a bdi
without holding a reference and pointer to it. This patch adds an
non-recycling bdi->id and implements bdi_get_by_id() which looks up
bdis by their ids. This will be used by memcg foreign inode flushing.
I left bdi_list alone for simplicity and because while rb_tree does
support rcu assignment it doesn't seem to guarantee lossless walk when
walk is racing aginst tree rebalance operations.
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The code like this:
ptr = kmalloc(size, GFP_KERNEL);
page = virt_to_page(ptr);
offset = offset_in_page(ptr);
kfree(page_address(page) + offset);
may produce false-positive invalid-free reports on the kernel with
CONFIG_KASAN_SW_TAGS=y.
In the example above we lose the original tag assigned to 'ptr', so
kfree() gets the pointer with 0xFF tag. In kfree() we check that 0xFF
tag is different from the tag in shadow hence print false report.
Instead of just comparing tags, do the following:
1) Check that shadow doesn't contain KASAN_TAG_INVALID. Otherwise it's
double-free and it doesn't matter what tag the pointer have.
2) If pointer tag is different from 0xFF, make sure that tag in the
shadow is the same as in the pointer.
Link: http://lkml.kernel.org/r/20190819172540.19581-1-aryabinin@virtuozzo.com
Fixes: 7f94ffbc4c ("kasan: add hooks implementation for tag-based mode")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Walter Wu <walter-zh.wu@mediatek.com>
Reported-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In zs_destroy_pool() we call flush_work(&pool->free_work). However, we
have no guarantee that migration isn't happening in the background at
that time.
Since migration can't directly free pages, it relies on free_work being
scheduled to free the pages. But there's nothing preventing an
in-progress migrate from queuing the work *after*
zs_unregister_migration() has called flush_work(). Which would mean
pages still pointing at the inode when we free it.
Since we know at destroy time all objects should be free, no new
migrations can come in (since zs_page_isolate() fails for fully-free
zspages). This means it is sufficient to track a "# isolated zspages"
count by class, and have the destroy logic ensure all such pages have
drained before proceeding. Keeping that state under the class spinlock
keeps the logic straightforward.
In this case a memory leak could lead to an eventual crash if compaction
hits the leaked page. This crash would only occur if people are
changing their zswap backend at runtime (which eventually starts
destruction).
Link: http://lkml.kernel.org/r/20190809181751.219326-2-henryburns@google.com
Fixes: 48b4800a1c ("zsmalloc: page migration support")
Signed-off-by: Henry Burns <henryburns@google.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Jonathan Adams <jwadams@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In zs_page_migrate() we call putback_zspage() after we have finished
migrating all pages in this zspage. However, the return value is
ignored. If a zs_free() races in between zs_page_isolate() and
zs_page_migrate(), freeing the last object in the zspage,
putback_zspage() will leave the page in ZS_EMPTY for potentially an
unbounded amount of time.
To fix this, we need to do the same thing as zs_page_putback() does:
schedule free_work to occur.
To avoid duplicated code, move the sequence to a new
putback_zspage_deferred() function which both zs_page_migrate() and
zs_page_putback() call.
Link: http://lkml.kernel.org/r/20190809181751.219326-1-henryburns@google.com
Fixes: 48b4800a1c ("zsmalloc: page migration support")
Signed-off-by: Henry Burns <henryburns@google.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Jonathan Adams <jwadams@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
THP splitting path is missing the split_page_owner() call that
split_page() has.
As a result, split THP pages are wrongly reported in the page_owner file
as order-9 pages. Furthermore when the former head page is freed, the
remaining former tail pages are not listed in the page_owner file at
all. This patch fixes that by adding the split_page_owner() call into
__split_huge_page().
Link: http://lkml.kernel.org/r/20190820131828.22684-2-vbabka@suse.cz
Fixes: a9627bc5e3 ("mm/page_owner: introduce split_page_owner and replace manual handling")
Reported-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Similar to vmstats, percpu caching of local vmevents leads to an
accumulation of errors on non-leaf levels. This happens because some
leftovers may remain in percpu caches, so that they are never propagated
up by the cgroup tree and just disappear into nonexistence with on
releasing of the memory cgroup.
To fix this issue let's accumulate and propagate percpu vmevents values
before releasing the memory cgroup similar to what we're doing with
vmstats.
Since on cpu hotplug we do flush percpu vmstats anyway, we can iterate
only over online cpus.
Link: http://lkml.kernel.org/r/20190819202338.363363-4-guro@fb.com
Fixes: 42a3003535 ("mm: memcontrol: fix recursive statistics correctness & scalabilty")
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Percpu caching of local vmstats with the conditional propagation by the
cgroup tree leads to an accumulation of errors on non-leaf levels.
Let's imagine two nested memory cgroups A and A/B. Say, a process
belonging to A/B allocates 100 pagecache pages on the CPU 0. The percpu
cache will spill 3 times, so that 32*3=96 pages will be accounted to A/B
and A atomic vmstat counters, 4 pages will remain in the percpu cache.
Imagine A/B is nearby memory.max, so that every following allocation
triggers a direct reclaim on the local CPU. Say, each such attempt will
free 16 pages on a new cpu. That means every percpu cache will have -16
pages, except the first one, which will have 4 - 16 = -12. A/B and A
atomic counters will not be touched at all.
Now a user removes A/B. All percpu caches are freed and corresponding
vmstat numbers are forgotten. A has 96 pages more than expected.
As memory cgroups are created and destroyed, errors do accumulate. Even
1-2 pages differences can accumulate into large numbers.
To fix this issue let's accumulate and propagate percpu vmstat values
before releasing the memory cgroup. At this point these numbers are
stable and cannot be changed.
Since on cpu hotplug we do flush percpu vmstats anyway, we can iterate
only over online cpus.
Link: http://lkml.kernel.org/r/20190819202338.363363-2-guro@fb.com
Fixes: 42a3003535 ("mm: memcontrol: fix recursive statistics correctness & scalabilty")
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After commit 907ec5fca3 ("mm: zero remaining unavailable struct
pages"), struct page of reserved memory is zeroed. This causes
page->flags to be 0 and fixes issues related to reading
/proc/kpageflags, for example, of reserved memory.
The VM_BUG_ON() in move_freepages_block(), however, assumes that
page_zone() is meaningful even for reserved memory. That assumption is
no longer true after the aforementioned commit.
There's no reason why move_freepages_block() should be testing the
legitimacy of page_zone() for reserved memory; its scope is limited only
to pages on the zone's freelist.
Note that pfn_valid() can be true for reserved memory: there is a
backing struct page. The check for page_to_nid(page) is also buggy but
reserved memory normally only appears on node 0 so the zeroing doesn't
affect this.
Move the debug checks to after verifying PageBuddy is true. This
isolates the scope of the checks to only be for buddy pages which are on
the zone's freelist which move_freepages_block() is operating on. In
this case, an incorrect node or zone is a bug worthy of being warned
about (and the examination of struct page is acceptable bcause this
memory is not reserved).
Why does move_freepages_block() gets called on reserved memory? It's
simply math after finding a valid free page from the per-zone free area
to use as fallback. We find the beginning and end of the pageblock of
the valid page and that can bring us into memory that was reserved per
the e820. pfn_valid() is still true (it's backed by a struct page), but
since it's zero'd we shouldn't make any inferences here about comparing
its node or zone. The current node check just happens to succeed most
of the time by luck because reserved memory typically appears on node 0.
The fix here is to validate that we actually have buddy pages before
testing if there's any type of zone or node strangeness going on.
We noticed it almost immediately after bringing 907ec5fca3 in on
CONFIG_DEBUG_VM builds. It depends on finding specific free pages in
the per-zone free area where the math in move_freepages() will bring the
start or end pfn into reserved memory and wanting to claim that entire
pageblock as a new migratetype. So the path will be rare, require
CONFIG_DEBUG_VM, and require fallback to a different migratetype.
Some struct pages were already zeroed from reserve pages before
907ec5fca3c so it theoretically could trigger before this commit. I
think it's rare enough under a config option that most people don't run
that others may not have noticed. I wouldn't argue against a stable tag
and the backport should be easy enough, but probably wouldn't single out
a commit that this is fixing.
Mel said:
: The overhead of the debugging check is higher with this patch although
: it'll only affect debug builds and the path is not particularly hot.
: If this was a concern, I think it would be reasonable to simply remove
: the debugging check as the zone boundaries are checked in
: move_freepages_block and we never expect a zone/node to be smaller than
: a pageblock and stuck in the middle of another zone.
Link: http://lkml.kernel.org/r/alpine.DEB.2.21.1908122036560.10779@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In z3fold_destroy_pool() we call destroy_workqueue(&pool->compact_wq).
However, we have no guarantee that migration isn't happening in the
background at that time.
Migration directly calls queue_work_on(pool->compact_wq), if destruction
wins that race we are using a destroyed workqueue.
Link: http://lkml.kernel.org/r/20190809213828.202833-1-henryburns@google.com
Signed-off-by: Henry Burns <henryburns@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Jonathan Adams <jwadams@google.com>
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hmm_range_fault() may return NULL pages because some of the pfns are equal
to HMM_PFN_NONE. This happens randomly under memory pressure. The reason
is during the swapped out page pte path, hmm_vma_handle_pte() doesn't
update the fault variable from cpu_flags, so it failed to call
hmm_vam_do_fault() to swap the page in.
The fix is to call hmm_pte_need_fault() to update fault variable.
Fixes: 74eee180b9 ("mm/hmm/mirror: device page fault handler")
Link: https://lore.kernel.org/r/20190815205227.7949-1-Philip.Yang@amd.com
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: "Jérôme Glisse" <jglisse@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
mmu_notifier_unregister_no_release() and mmu_notifier_call_srcu() no
longer have any users, they have all been converted to use
mmu_notifier_put().
So delete this difficult to use interface.
Link: https://lore.kernel.org/r/20190806231548.25242-12-jgg@ziepe.ca
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
From rdma.git
Jason Gunthorpe says:
====================
This is a collection of general cleanups for ODP to clarify some of the
flows around umem creation and use of the interval tree.
====================
The branch is based on v5.3-rc5 due to dependencies, and is being taken
into hmm.git due to dependencies in the next patches.
* odp_fixes:
RDMA/mlx5: Use odp instead of mr->umem in pagefault_mr
RDMA/mlx5: Use ib_umem_start instead of umem.address
RDMA/core: Make invalidate_range a device operation
RDMA/odp: Use kvcalloc for the dma_list and page_list
RDMA/odp: Check for overflow when computing the umem_odp end
RDMA/odp: Provide ib_umem_odp_release() to undo the allocs
RDMA/odp: Split creating a umem_odp from ib_umem_get
RDMA/odp: Make the three ways to create a umem_odp clear
RMDA/odp: Consolidate umem_odp initialization
RDMA/odp: Make it clearer when a umem is an implicit ODP umem
RDMA/odp: Iterate over the whole rbtree directly
RDMA/odp: Use the common interval tree library instead of generic
RDMA/mlx5: Fix MR npages calculation for IB_ACCESS_HUGETLB
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Don't let userspace write to an active swap file because the kernel
effectively has a long term lease on the storage and things could get
seriously corrupted if we let this happen.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Set S_SWAPFILE on block device inodes so that they have the same
protections as a swap flie.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
The dev field in struct dev_pagemap is only used to print dev_name in two
places, which are at best nice to have. Just remove the field and thus
the name in those two messages.
Link: https://lore.kernel.org/r/20190818090557.17853-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Bharata B Rao <bharata@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Just a bit of paranoia, since if we start pushing this deep into
callchains it's hard to spot all places where an mmu notifier
implementation might fail when it's not allowed to.
Inspired by some confusion we had discussing i915 mmu notifiers and
whether we could use the newly-introduced return value to handle some
corner cases. Until we realized that these are only for when a task has
been killed by the oom reaper.
An alternative approach would be to split the callback into two versions,
one with the int return value, and the other with void return value like
in older kernels. But that's a lot more churn for fairly little gain I
think.
Summary from the m-l discussion on why we want something at warning level:
This allows automated tooling in CI to catch bugs without humans having to
look at everything. If we just upgrade the existing pr_info to a pr_warn,
then we'll have false positives. And as-is, no one will ever spot the
problem since it's lost in the massive amounts of overall dmesg noise.
Link: https://lore.kernel.org/r/20190814202027.18735-2-daniel.vetter@ffwll.ch
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
CONFIG_MIGRATE_VMA_HELPER guards helpers that are required for proper
devic private memory support. Remove the option and just check for
CONFIG_DEVICE_PRIVATE instead.
Link: https://lore.kernel.org/r/20190814075928.23766-11-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
No one ever checks this flag, and we could easily get that information
from the page if needed.
Link: https://lore.kernel.org/r/20190814075928.23766-10-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
There isn't any good reason to pass callbacks to migrate_vma. Instead
we can just export the three steps done by this function to drivers and
let them sequence the operation without callbacks. This removes a lot
of boilerplate code as-is, and will allow the drivers to drastically
improve code flow and error handling further on.
Link: https://lore.kernel.org/r/20190814075928.23766-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This is a significant simplification, it eliminates all the remaining
'hmm' stuff in mm_struct, eliminates krefing along the critical notifier
paths, and takes away all the ugly locking and abuse of page_table_lock.
mmu_notifier_get() provides the single struct hmm per struct mm which
eliminates mm->hmm.
It also directly guarantees that no mmu_notifier op callback is callable
while concurrent free is possible, this eliminates all the krefs inside
the mmu_notifier callbacks.
The remaining krefs in the range code were overly cautious, drivers are
already not permitted to free the mirror while a range exists.
Link: https://lore.kernel.org/r/20190806231548.25242-6-jgg@ziepe.ca
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Many places in the kernel have a flow where userspace will create some
object and that object will need to connect to the subsystem's
mmu_notifier subscription for the duration of its lifetime.
In this case the subsystem is usually tracking multiple mm_structs and it
is difficult to keep track of what struct mmu_notifier's have been
allocated for what mm's.
Since this has been open coded in a variety of exciting ways, provide core
functionality to do this safely.
This approach uses the struct mmu_notifier_ops * as a key to determine if
the subsystem has a notifier registered on the mm or not. If there is a
registration then the existing notifier struct is returned, otherwise the
ops->alloc_notifiers() is used to create a new per-subsystem notifier for
the mm.
The destroy side incorporates an async call_srcu based destruction which
will avoid bugs in the callers such as commit 6d7c3cde93 ("mm/hmm: fix
use after free with struct hmm in the mmu notifiers").
Since we are inside the mmu notifier core locking is fairly simple, the
allocation uses the same approach as for mmu_notifier_mm, the write side
of the mmap_sem makes everything deterministic and we only need to do
hlist_add_head_rcu() under the mm_take_all_locks(). The new users count
and the discoverability in the hlist is fully serialized by the
mmu_notifier_mm->lock.
Link: https://lore.kernel.org/r/20190806231548.25242-4-jgg@ziepe.ca
Co-developed-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
A prior commit e0f3c3f78d ("mm/mmu_notifier: init notifier if necessary")
made an attempt at doing this, but had to be reverted as calling
the GFP_KERNEL allocator under the i_mmap_mutex causes deadlock, see
commit 35cfa2b0b4 ("mm/mmu_notifier: allocate mmu_notifier in advance").
However, we can avoid that problem by doing the allocation only under
the mmap_sem, which is already happening.
Since all writers to mm->mmu_notifier_mm hold the write side of the
mmap_sem reading it under that sem is deterministic and we can use that to
decide if the allocation path is required, without speculation.
The actual update to mmu_notifier_mm must still be done under the
mm_take_all_locks() to ensure read-side coherency.
Link: https://lore.kernel.org/r/20190806231548.25242-3-jgg@ziepe.ca
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This simplifies the code to not have so many one line functions and extra
logic. __mmu_notifier_register() simply becomes the entry point to
register the notifier, and the other one calls it under lock.
Also add a lockdep_assert to check that the callers are holding the lock
as expected.
Link: https://lore.kernel.org/r/20190806231548.25242-2-jgg@ziepe.ca
Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Li Wang discovered that LTP/move_page12 V2 sometimes triggers SIGBUS in
the kernel-v5.2.3 testing. This is caused by a race between hugetlb
page migration and page fault.
If a hugetlb page can not be allocated to satisfy a page fault, the task
is sent SIGBUS. This is normal hugetlbfs behavior. A hugetlb fault
mutex exists to prevent two tasks from trying to instantiate the same
page. This protects against the situation where there is only one
hugetlb page, and both tasks would try to allocate. Without the mutex,
one would fail and SIGBUS even though the other fault would be
successful.
There is a similar race between hugetlb page migration and fault.
Migration code will allocate a page for the target of the migration. It
will then unmap the original page from all page tables. It does this
unmap by first clearing the pte and then writing a migration entry. The
page table lock is held for the duration of this clear and write
operation. However, the beginnings of the hugetlb page fault code
optimistically checks the pte without taking the page table lock. If
clear (as it can be during the migration unmap operation), a hugetlb
page allocation is attempted to satisfy the fault. Note that the page
which will eventually satisfy this fault was already allocated by the
migration code. However, the allocation within the fault path could
fail which would result in the task incorrectly being sent SIGBUS.
Ideally, we could take the hugetlb fault mutex in the migration code
when modifying the page tables. However, locks must be taken in the
order of hugetlb fault mutex, page lock, page table lock. This would
require significant rework of the migration code. Instead, the issue is
addressed in the hugetlb fault code. After failing to allocate a huge
page, take the page table lock and check for huge_pte_none before
returning an error. This is the same check that must be made further in
the code even if page allocation is successful.
Link: http://lkml.kernel.org/r/20190808000533.7701-1-mike.kravetz@oracle.com
Fixes: 290408d4a2 ("hugetlb: hugepage migration core")
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Li Wang <liwang@redhat.com>
Tested-by: Li Wang <liwang@redhat.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Cyril Hrubis <chrubis@suse.cz>
Cc: Xishi Qiu <xishi.qiuxishi@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dave Chinner reported a problem pointing a finger at commit 1c30844d2d
("mm: reclaim small amounts of memory when an external fragmentation
event occurs").
The report is extensive:
https://lore.kernel.org/linux-mm/20190807091858.2857-1-david@fromorbit.com/
and it's worth recording the most relevant parts (colorful language and
typos included).
When running a simple, steady state 4kB file creation test to
simulate extracting tarballs larger than memory full of small
files into the filesystem, I noticed that once memory fills up
the cache balance goes to hell.
The workload is creating one dirty cached inode for every dirty
page, both of which should require a single IO each to clean and
reclaim, and creation of inodes is throttled by the rate at which
dirty writeback runs at (via balance dirty pages). Hence the ingest
rate of new cached inodes and page cache pages is identical and
steady. As a result, memory reclaim should quickly find a steady
balance between page cache and inode caches.
The moment memory fills, the page cache is reclaimed at a much
faster rate than the inode cache, and evidence suggests that
the inode cache shrinker is not being called when large batches
of pages are being reclaimed. In roughly the same time period
that it takes to fill memory with 50% pages and 50% slab caches,
memory reclaim reduces the page cache down to just dirty pages
and slab caches fill the entirety of memory.
The LRU is largely full of dirty pages, and we're getting spikes
of random writeback from memory reclaim so it's all going to shit.
Behaviour never recovers, the page cache remains pinned at just
dirty pages, and nothing I could tune would make any difference.
vfs_cache_pressure makes no difference - I would set it so high
it should trim the entire inode caches in a single pass, yet it
didn't do anything. It was clear from tracing and live telemetry
that the shrinkers were pretty much not running except when
there was absolutely no memory free at all, and then they did
the minimum necessary to free memory to make progress.
So I went looking at the code, trying to find places where pages
got reclaimed and the shrinkers weren't called. There's only one
- kswapd doing boosted reclaim as per commit 1c30844d2d ("mm:
reclaim small amounts of memory when an external fragmentation
event occurs").
The watermark boosting introduced by the commit is triggered in response
to an allocation "fragmentation event". The boosting was not intended
to target THP specifically and triggers even if THP is disabled.
However, with Dave's perfectly reasonable workload, fragmentation events
can be very common given the ratio of slab to page cache allocations so
boosting remains active for long periods of time.
As high-order allocations might use compaction and compaction cannot
move slab pages the decision was made in the commit to special-case
kswapd when watermarks are boosted -- kswapd avoids reclaiming slab as
reclaiming slab does not directly help compaction.
As Dave notes, this decision means that slab can be artificially
protected for long periods of time and messes up the balance with slab
and page caches.
Removing the special casing can still indirectly help avoid
fragmentation by avoiding fragmentation-causing events due to slab
allocation as pages from a slab pageblock will have some slab objects
freed. Furthermore, with the special casing, reclaim behaviour is
unpredictable as kswapd sometimes examines slab and sometimes does not
in a manner that is tricky to tune or analyse.
This patch removes the special casing. The downside is that this is not
a universal performance win. Some benchmarks that depend on the
residency of data when rereading metadata may see a regression when slab
reclaim is restored to its original behaviour. Similarly, some
benchmarks that only read-once or write-once may perform better when
page reclaim is too aggressive. The primary upside is that slab
shrinker is less surprising (arguably more sane but that's a matter of
opinion), behaves consistently regardless of the fragmentation state of
the system and properly obeys VM sysctls.
A fsmark benchmark configuration was constructed similar to what Dave
reported and is codified by the mmtest configuration
config-io-fsmark-small-file-stream. It was evaluated on a 1-socket
machine to avoid dealing with NUMA-related issues and the timing of
reclaim. The storage was an SSD Samsung Evo and a fresh trimmed XFS
filesystem was used for the test data.
This is not an exact replication of Dave's setup. The configuration
scales its parameters depending on the memory size of the SUT to behave
similarly across machines. The parameters mean the first sample
reported by fs_mark is using 50% of RAM which will barely be throttled
and look like a big outlier. Dave used fake NUMA to have multiple
kswapd instances which I didn't replicate. Finally, the number of
iterations differ from Dave's test as the target disk was not large
enough. While not identical, it should be representative.
fsmark
5.3.0-rc3 5.3.0-rc3
vanilla shrinker-v1r1
Min 1-files/sec 4444.80 ( 0.00%) 4765.60 ( 7.22%)
1st-qrtle 1-files/sec 5005.10 ( 0.00%) 5091.70 ( 1.73%)
2nd-qrtle 1-files/sec 4917.80 ( 0.00%) 4855.60 ( -1.26%)
3rd-qrtle 1-files/sec 4667.40 ( 0.00%) 4831.20 ( 3.51%)
Max-1 1-files/sec 11421.50 ( 0.00%) 9999.30 ( -12.45%)
Max-5 1-files/sec 11421.50 ( 0.00%) 9999.30 ( -12.45%)
Max-10 1-files/sec 11421.50 ( 0.00%) 9999.30 ( -12.45%)
Max-90 1-files/sec 4649.60 ( 0.00%) 4780.70 ( 2.82%)
Max-95 1-files/sec 4491.00 ( 0.00%) 4768.20 ( 6.17%)
Max-99 1-files/sec 4491.00 ( 0.00%) 4768.20 ( 6.17%)
Max 1-files/sec 11421.50 ( 0.00%) 9999.30 ( -12.45%)
Hmean 1-files/sec 5004.75 ( 0.00%) 5075.96 ( 1.42%)
Stddev 1-files/sec 1778.70 ( 0.00%) 1369.66 ( 23.00%)
CoeffVar 1-files/sec 33.70 ( 0.00%) 26.05 ( 22.71%)
BHmean-99 1-files/sec 5053.72 ( 0.00%) 5101.52 ( 0.95%)
BHmean-95 1-files/sec 5053.72 ( 0.00%) 5101.52 ( 0.95%)
BHmean-90 1-files/sec 5107.05 ( 0.00%) 5131.41 ( 0.48%)
BHmean-75 1-files/sec 5208.45 ( 0.00%) 5206.68 ( -0.03%)
BHmean-50 1-files/sec 5405.53 ( 0.00%) 5381.62 ( -0.44%)
BHmean-25 1-files/sec 6179.75 ( 0.00%) 6095.14 ( -1.37%)
5.3.0-rc3 5.3.0-rc3
vanillashrinker-v1r1
Duration User 501.82 497.29
Duration System 4401.44 4424.08
Duration Elapsed 8124.76 8358.05
This is showing a slight skew for the max result representing a large
outlier for the 1st, 2nd and 3rd quartile are similar indicating that
the bulk of the results show little difference. Note that an earlier
version of the fsmark configuration showed a regression but that
included more samples taken while memory was still filling.
Note that the elapsed time is higher. Part of this is that the
configuration included time to delete all the test files when the test
completes -- the test automation handles the possibility of testing
fsmark with multiple thread counts. Without the patch, many of these
objects would be memory resident which is part of what the patch is
addressing.
There are other important observations that justify the patch.
1. With the vanilla kernel, the number of dirty pages in the system is
very low for much of the test. With this patch, dirty pages is
generally kept at 10% which matches vm.dirty_background_ratio which
is normal expected historical behaviour.
2. With the vanilla kernel, the ratio of Slab/Pagecache is close to
0.95 for much of the test i.e. Slab is being left alone and
dominating memory consumption. With the patch applied, the ratio
varies between 0.35 and 0.45 with the bulk of the measured ratios
roughly half way between those values. This is a different balance to
what Dave reported but it was at least consistent.
3. Slabs are scanned throughout the entire test with the patch applied.
The vanille kernel has periods with no scan activity and then
relatively massive spikes.
4. Without the patch, kswapd scan rates are very variable. With the
patch, the scan rates remain quite steady.
4. Overall vmstats are closer to normal expectations
5.3.0-rc3 5.3.0-rc3
vanilla shrinker-v1r1
Ops Direct pages scanned 99388.00 328410.00
Ops Kswapd pages scanned 45382917.00 33451026.00
Ops Kswapd pages reclaimed 30869570.00 25239655.00
Ops Direct pages reclaimed 74131.00 5830.00
Ops Kswapd efficiency % 68.02 75.45
Ops Kswapd velocity 5585.75 4002.25
Ops Page reclaim immediate 1179721.00 430927.00
Ops Slabs scanned 62367361.00 73581394.00
Ops Direct inode steals 2103.00 1002.00
Ops Kswapd inode steals 570180.00 5183206.00
o Vanilla kernel is hitting direct reclaim more frequently,
not very much in absolute terms but the fact the patch
reduces it is interesting
o "Page reclaim immediate" in the vanilla kernel indicates
dirty pages are being encountered at the tail of the LRU.
This is generally bad and means in this case that the LRU
is not long enough for dirty pages to be cleaned by the
background flush in time. This is much reduced by the
patch.
o With the patch, kswapd is reclaiming 10 times more slab
pages than with the vanilla kernel. This is indicative
of the watermark boosting over-protecting slab
A more complete set of tests were run that were part of the basis for
introducing boosting and while there are some differences, they are well
within tolerances.
Bottom line, the special casing kswapd to avoid slab behaviour is
unpredictable and can lead to abnormal results for normal workloads.
This patch restores the expected behaviour that slab and page cache is
balanced consistently for a workload with a steady allocation ratio of
slab/pagecache pages. It also means that if there are workloads that
favour the preservation of slab over pagecache that it can be tuned via
vm.vfs_cache_pressure where as the vanilla kernel effectively ignores
the parameter when boosting is active.
Link: http://lkml.kernel.org/r/20190808182946.GM2739@techsingularity.net
Fixes: 1c30844d2d ("mm: reclaim small amounts of memory when an external fragmentation event occurs")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org> [5.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 2f0799a0ff ("mm, thp: restore node-local
hugepage allocations").
commit 2f0799a0ff was rightfully applied to avoid the risk of a
severe regression that was reported by the kernel test robot at the end
of the merge window. Now we understood the regression was a false
positive and was caused by a significant increase in fairness during a
swap trashing benchmark. So it's safe to re-apply the fix and continue
improving the code from there. The benchmark that reported the
regression is very useful, but it provides a meaningful result only when
there is no significant alteration in fairness during the workload. The
removal of __GFP_THISNODE increased fairness.
__GFP_THISNODE cannot be used in the generic page faults path for new
memory allocations under the MPOL_DEFAULT mempolicy, or the allocation
behavior significantly deviates from what the MPOL_DEFAULT semantics are
supposed to be for THP and 4k allocations alike.
Setting THP defrag to "always" or using MADV_HUGEPAGE (with THP defrag
set to "madvise") has never meant to provide an implicit MPOL_BIND on
the "current" node the task is running on, causing swap storms and
providing a much more aggressive behavior than even zone_reclaim_node =
3.
Any workload who could have benefited from __GFP_THISNODE has now to
enable zone_reclaim_mode=1||2||3. __GFP_THISNODE implicitly provided
the zone_reclaim_mode behavior, but it only did so if THP was enabled:
if THP was disabled, there would have been no chance to get any 4k page
from the current node if the current node was full of pagecache, which
further shows how this __GFP_THISNODE was misplaced in MADV_HUGEPAGE.
MADV_HUGEPAGE has never been intended to provide any zone_reclaim_mode
semantics, in fact the two are orthogonal, zone_reclaim_mode = 1|2|3
must work exactly the same with MADV_HUGEPAGE set or not.
The performance characteristic of memory depends on the hardware
details. The numbers below are obtained on Naples/EPYC architecture and
the N/A projection extends them to show what we should aim for in the
future as a good THP NUMA locality default. The benchmark used
exercises random memory seeks (note: the cost of the page faults is not
part of the measurement).
D0 THP | D0 4k | D1 THP | D1 4k | D2 THP | D2 4k | D3 THP | D3 4k | ...
0% | +43% | +45% | +106% | +131% | +224% | N/A | N/A
D0 means distance zero (i.e. local memory), D1 means distance one (i.e.
intra socket memory), D2 means distance two (i.e. inter socket memory),
etc...
For the guest physical memory allocated by qemu and for guest mode
kernel the performance characteristic of RAM is more complex and an
ideal default could be:
D0 THP | D1 THP | D0 4k | D2 THP | D1 4k | D3 THP | D2 4k | D3 4k | ...
0% | +58% | +101% | N/A | +222% | N/A | N/A | N/A
NOTE: the N/A are projections and haven't been measured yet, the
measurement in this case is done on a 1950x with only two NUMA nodes.
The THP case here means THP was used both in the host and in the guest.
After applying this commit the THP NUMA locality order that we'll get
out of MADV_HUGEPAGE is this:
D0 THP | D1 THP | D2 THP | D3 THP | ... | D0 4k | D1 4k | D2 4k | D3 4k | ...
Before this commit it was:
D0 THP | D0 4k | D1 4k | D2 4k | D3 4k | ...
Even if we ignore the breakage of large workloads that can't fit in a
single node that the __GFP_THISNODE implicit "current node" mbind
caused, the THP NUMA locality order provided by __GFP_THISNODE was still
not the one we shall aim for in the long term (i.e. the first one at
the top).
After this commit is applied, we can introduce a new allocator multi
order API and to replace those two alloc_pages_vmas calls in the page
fault path, with a single multi order call:
unsigned int order = (1 << HPAGE_PMD_ORDER) | (1 << 0);
page = alloc_pages_multi_order(..., &order);
if (!page)
goto out;
if (!(order & (1 << 0))) {
VM_WARN_ON(order != 1 << HPAGE_PMD_ORDER);
/* THP fault */
} else {
VM_WARN_ON(order != 1 << 0);
/* 4k fallback */
}
The page allocator logic has to be altered so that when it fails on any
zone with order 9, it has to try again with a order 0 before falling
back to the next zone in the zonelist.
After that we need to do more measurements and evaluate if adding an
opt-in feature for guest mode is worth it, to swap "DN 4k | DN+1 THP"
with "DN+1 THP | DN 4k" at every NUMA distance crossing.
Link: http://lkml.kernel.org/r/20190503223146.2312-3-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "reapply: relax __GFP_THISNODE for MADV_HUGEPAGE mappings".
The fixes for what was originally reported as "pathological THP
behavior" we rightfully reverted to be sure not to introduced
regressions at end of a merge window after a severe regression report
from the kernel bot. We can safely re-apply them now that we had time
to analyze the problem.
The mm process worked fine, because the good fixes were eventually
committed upstream without excessive delay.
The regression reported by the kernel bot however forced us to revert
the good fixes to be sure not to introduce regressions and to give us
the time to analyze the issue further. The silver lining is that this
extra time allowed to think more at this issue and also plan for a
future direction to improve things further in terms of THP NUMA
locality.
This patch (of 2):
This reverts commit 356ff8a9a7 ("Revert "mm, thp: consolidate THP
gfp handling into alloc_hugepage_direct_gfpmask"). So it reapplies
89c83fb539 ("mm, thp: consolidate THP gfp handling into
alloc_hugepage_direct_gfpmask").
Consolidation of the THP allocation flags at the same place was meant to
be a clean up to easier handle otherwise scattered code which is
imposing a maintenance burden. There were no real problems observed
with the gfp mask consolidation but the reversion was rushed through
without a larger consensus regardless.
This patch brings the consolidation back because this should make the
long term maintainability easier as well as it should allow future
changes to be less error prone.
[mhocko@kernel.org: changelog additions]
Link: http://lkml.kernel.org/r/20190503223146.2312-2-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Stefan Priebe - Profihost AG <s.priebe@profihost.ag>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Memcg counters for shadow nodes are broken because the memcg pointer is
obtained in a wrong way. The following approach is used:
virt_to_page(xa_node)->mem_cgroup
Since commit 4d96ba3530 ("mm: memcg/slab: stop setting
page->mem_cgroup pointer for slab pages") page->mem_cgroup pointer isn't
set for slab pages, so memcg_from_slab_page() should be used instead.
Also I doubt that it ever worked correctly: virt_to_head_page() should
be used instead of virt_to_page(). Otherwise objects residing on tail
pages are not accounted, because only the head page contains a valid
mem_cgroup pointer. That was a case since the introduction of these
counters by the commit 68d48e6a2d ("mm: workingset: add vmstat counter
for shadow nodes").
Link: http://lkml.kernel.org/r/20190801233532.138743-1-guro@fb.com
Fixes: 4d96ba3530 ("mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages")
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, when checking to see if accessing n bytes starting at address
"ptr" will cause a wraparound in the memory addresses, the check in
check_bogus_address() adds an extra byte, which is incorrect, as the
range of addresses that will be accessed is [ptr, ptr + (n - 1)].
This can lead to incorrectly detecting a wraparound in the memory
address, when trying to read 4 KB from memory that is mapped to the the
last possible page in the virtual address space, when in fact, accessing
that range of memory would not cause a wraparound to occur.
Use the memory range that will actually be accessed when considering if
accessing a certain amount of bytes will cause the memory address to
wrap around.
Link: http://lkml.kernel.org/r/1564509253-23287-1-git-send-email-isaacm@codeaurora.org
Fixes: f5509cc18d ("mm: Hardened usercopy")
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Co-developed-by: Prasad Sodagudi <psodagud@codeaurora.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Trilok Soni <tsoni@codeaurora.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If an error occurs during kmemleak_init() (e.g. kmem cache cannot be
created), kmemleak is disabled but kmemleak_early_log remains enabled.
Subsequently, when the .init.text section is freed, the log_early()
function no longer exists. To avoid a page fault in such scenario,
ensure that kmemleak_disable() also disables early logging.
Link: http://lkml.kernel.org/r/20190731152302.42073-1-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Recent changes to the vmalloc code by commit 68ad4a3304
("mm/vmalloc.c: keep track of free blocks for vmap allocation") can
cause spurious percpu allocation failures. These, in turn, can result
in panic()s in the slub code. One such possible panic was reported by
Dave Hansen in following link https://lkml.org/lkml/2019/6/19/939.
Another related panic observed is,
RIP: 0033:0x7f46f7441b9b
Call Trace:
dump_stack+0x61/0x80
pcpu_alloc.cold.30+0x22/0x4f
mem_cgroup_css_alloc+0x110/0x650
cgroup_apply_control_enable+0x133/0x330
cgroup_mkdir+0x41b/0x500
kernfs_iop_mkdir+0x5a/0x90
vfs_mkdir+0x102/0x1b0
do_mkdirat+0x7d/0xf0
do_syscall_64+0x5b/0x180
entry_SYSCALL_64_after_hwframe+0x44/0xa9
VMALLOC memory manager divides the entire VMALLOC space (VMALLOC_START
to VMALLOC_END) into multiple VM areas (struct vm_areas), and it mainly
uses two lists (vmap_area_list & free_vmap_area_list) to track the used
and free VM areas in VMALLOC space. And pcpu_get_vm_areas(offsets[],
sizes[], nr_vms, align) function is used for allocating congruent VM
areas for percpu memory allocator. In order to not conflict with
VMALLOC users, pcpu_get_vm_areas allocates VM areas near the end of the
VMALLOC space. So the search for free vm_area for the given requirement
starts near VMALLOC_END and moves upwards towards VMALLOC_START.
Prior to commit 68ad4a3304, the search for free vm_area in
pcpu_get_vm_areas() involves following two main steps.
Step 1:
Find a aligned "base" adress near VMALLOC_END.
va = free vm area near VMALLOC_END
Step 2:
Loop through number of requested vm_areas and check,
Step 2.1:
if (base < VMALLOC_START)
1. fail with error
Step 2.2:
// end is offsets[area] + sizes[area]
if (base + end > va->vm_end)
1. Move the base downwards and repeat Step 2
Step 2.3:
if (base + start < va->vm_start)
1. Move to previous free vm_area node, find aligned
base address and repeat Step 2
But Commit 68ad4a3304 removed Step 2.2 and modified Step 2.3 as below:
Step 2.3:
if (base + start < va->vm_start || base + end > va->vm_end)
1. Move to previous free vm_area node, find aligned
base address and repeat Step 2
Above change is the root cause of spurious percpu memory allocation
failures. For example, consider a case where a relatively large vm_area
(~ 30 TB) was ignored in free vm_area search because it did not pass the
base + end < vm->vm_end boundary check. Ignoring such large free
vm_area's would lead to not finding free vm_area within boundary of
VMALLOC_start to VMALLOC_END which in turn leads to allocation failures.
So modify the search algorithm to include Step 2.2.
Link: http://lkml.kernel.org/r/20190729232139.91131-1-sathyanarayanan.kuppuswamy@linux.intel.com
Fixes: 68ad4a3304 ("mm/vmalloc.c: keep track of free blocks for vmap allocation")
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reported-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: sathyanarayanan kuppuswamy <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The constraint from the zpool use of z3fold_destroy_pool() is there are
no outstanding handles to memory (so no active allocations), but it is
possible for there to be outstanding work on either of the two wqs in
the pool.
Calling z3fold_deregister_migration() before the workqueues are drained
means that there can be allocated pages referencing a freed inode,
causing any thread in compaction to be able to trip over the bad pointer
in PageMovable().
Link: http://lkml.kernel.org/r/20190726224810.79660-2-henryburns@google.com
Fixes: 1f862989b0 ("mm/z3fold.c: support page migration")
Signed-off-by: Henry Burns <henryburns@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Jonathan Adams <jwadams@google.com>
Cc: Vitaly Vul <vitaly.vul@sony.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The constraint from the zpool use of z3fold_destroy_pool() is there are
no outstanding handles to memory (so no active allocations), but it is
possible for there to be outstanding work on either of the two wqs in
the pool.
If there is work queued on pool->compact_workqueue when it is called,
z3fold_destroy_pool() will do:
z3fold_destroy_pool()
destroy_workqueue(pool->release_wq)
destroy_workqueue(pool->compact_wq)
drain_workqueue(pool->compact_wq)
do_compact_page(zhdr)
kref_put(&zhdr->refcount)
__release_z3fold_page(zhdr, ...)
queue_work_on(pool->release_wq, &pool->work) *BOOM*
So compact_wq needs to be destroyed before release_wq.
Link: http://lkml.kernel.org/r/20190726224810.79660-1-henryburns@google.com
Fixes: 5d03a66139 ("mm/z3fold.c: use kref to prevent page free/compact race")
Signed-off-by: Henry Burns <henryburns@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Jonathan Adams <jwadams@google.com>
Cc: Vitaly Vul <vitaly.vul@sony.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk
Cc: Henry Burns <henrywolfeburns@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When running syzkaller internally, we ran into the below bug on 4.9.x
kernel:
kernel BUG at mm/huge_memory.c:2124!
invalid opcode: 0000 [#1] SMP KASAN
CPU: 0 PID: 1518 Comm: syz-executor107 Not tainted 4.9.168+ #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.5.1 01/01/2011
task: ffff880067b34900 task.stack: ffff880068998000
RIP: split_huge_page_to_list+0x8fb/0x1030 mm/huge_memory.c:2124
Call Trace:
split_huge_page include/linux/huge_mm.h:100 [inline]
queue_pages_pte_range+0x7e1/0x1480 mm/mempolicy.c:538
walk_pmd_range mm/pagewalk.c:50 [inline]
walk_pud_range mm/pagewalk.c:90 [inline]
walk_pgd_range mm/pagewalk.c:116 [inline]
__walk_page_range+0x44a/0xdb0 mm/pagewalk.c:208
walk_page_range+0x154/0x370 mm/pagewalk.c:285
queue_pages_range+0x115/0x150 mm/mempolicy.c:694
do_mbind mm/mempolicy.c:1241 [inline]
SYSC_mbind+0x3c3/0x1030 mm/mempolicy.c:1370
SyS_mbind+0x46/0x60 mm/mempolicy.c:1352
do_syscall_64+0x1d2/0x600 arch/x86/entry/common.c:282
entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: c7 80 1c 02 00 e8 26 0a 76 01 <0f> 0b 48 c7 c7 40 46 45 84 e8 4c
RIP [<ffffffff81895d6b>] split_huge_page_to_list+0x8fb/0x1030 mm/huge_memory.c:2124
RSP <ffff88006899f980>
with the below test:
uint64_t r[1] = {0xffffffffffffffff};
int main(void)
{
syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
intptr_t res = 0;
res = syscall(__NR_socket, 0x11, 3, 0x300);
if (res != -1)
r[0] = res;
*(uint32_t*)0x20000040 = 0x10000;
*(uint32_t*)0x20000044 = 1;
*(uint32_t*)0x20000048 = 0xc520;
*(uint32_t*)0x2000004c = 1;
syscall(__NR_setsockopt, r[0], 0x107, 0xd, 0x20000040, 0x10);
syscall(__NR_mmap, 0x20fed000, 0x10000, 0, 0x8811, r[0], 0);
*(uint64_t*)0x20000340 = 2;
syscall(__NR_mbind, 0x20ff9000, 0x4000, 0x4002, 0x20000340, 0x45d4, 3);
return 0;
}
Actually the test does:
mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000
socket(AF_PACKET, SOCK_RAW, 768) = 3
setsockopt(3, SOL_PACKET, PACKET_TX_RING, {block_size=65536, block_nr=1, frame_size=50464, frame_nr=1}, 16) = 0
mmap(0x20fed000, 65536, PROT_NONE, MAP_SHARED|MAP_FIXED|MAP_POPULATE|MAP_DENYWRITE, 3, 0) = 0x20fed000
mbind(..., MPOL_MF_STRICT|MPOL_MF_MOVE) = 0
The setsockopt() would allocate compound pages (16 pages in this test)
for packet tx ring, then the mmap() would call packet_mmap() to map the
pages into the user address space specified by the mmap() call.
When calling mbind(), it would scan the vma to queue the pages for
migration to the new node. It would split any huge page since 4.9
doesn't support THP migration, however, the packet tx ring compound
pages are not THP and even not movable. So, the above bug is triggered.
However, the later kernel is not hit by this issue due to commit
d44d363f65 ("mm: don't assume anonymous pages have SwapBacked flag"),
which just removes the PageSwapBacked check for a different reason.
But, there is a deeper issue. According to the semantic of mbind(), it
should return -EIO if MPOL_MF_MOVE or MPOL_MF_MOVE_ALL was specified and
MPOL_MF_STRICT was also specified, but the kernel was unable to move all
existing pages in the range. The tx ring of the packet socket is
definitely not movable, however, mbind() returns success for this case.
Although the most socket file associates with non-movable pages, but XDP
may have movable pages from gup. So, it sounds not fine to just check
the underlying file type of vma in vma_migratable().
Change migrate_page_add() to check if the page is movable or not, if it
is unmovable, just return -EIO. But do not abort pte walk immediately,
since there may be pages off LRU temporarily. We should migrate other
pages if MPOL_MF_MOVE* is specified. Set has_unmovable flag if some
paged could not be not moved, then return -EIO for mbind() eventually.
With this change the above test would return -EIO as expected.
[yang.shi@linux.alibaba.com: fix review comments from Vlastimil]
Link: http://lkml.kernel.org/r/1563556862-54056-3-git-send-email-yang.shi@linux.alibaba.com
Link: http://lkml.kernel.org/r/1561162809-59140-3-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When both MPOL_MF_MOVE* and MPOL_MF_STRICT was specified, mbind() should
try best to migrate misplaced pages, if some of the pages could not be
migrated, then return -EIO.
There are three different sub-cases:
1. vma is not migratable
2. vma is migratable, but there are unmovable pages
3. vma is migratable, pages are movable, but migrate_pages() fails
If #1 happens, kernel would just abort immediately, then return -EIO,
after a7f40cfe3b ("mm: mempolicy: make mbind() return -EIO when
MPOL_MF_STRICT is specified").
If #3 happens, kernel would set policy and migrate pages with
best-effort, but won't rollback the migrated pages and reset the policy
back.
Before that commit, they behaves in the same way. It'd better to keep
their behavior consistent. But, rolling back the migrated pages and
resetting the policy back sounds not feasible, so just make #1 behave as
same as #3.
Userspace will know that not everything was successfully migrated (via
-EIO), and can take whatever steps it deems necessary - attempt
rollback, determine which exact page(s) are violating the policy, etc.
Make queue_pages_range() return 1 to indicate there are unmovable pages
or vma is not migratable.
The #2 is not handled correctly in the current kernel, the following
patch will fix it.
[yang.shi@linux.alibaba.com: fix review comments from Vlastimil]
Link: http://lkml.kernel.org/r/1563556862-54056-2-git-send-email-yang.shi@linux.alibaba.com
Link: http://lkml.kernel.org/r/1561162809-59140-2-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When migrating an anonymous private page to a ZONE_DEVICE private page,
the source page->mapping and page->index fields are copied to the
destination ZONE_DEVICE struct page and the page_mapcount() is
increased. This is so rmap_walk() can be used to unmap and migrate the
page back to system memory.
However, try_to_unmap_one() computes the subpage pointer from a swap pte
which computes an invalid page pointer and a kernel panic results such
as:
BUG: unable to handle page fault for address: ffffea1fffffffc8
Currently, only single pages can be migrated to device private memory so
no subpage computation is needed and it can be set to "page".
[rcampbell@nvidia.com: add comment]
Link: http://lkml.kernel.org/r/20190724232700.23327-4-rcampbell@nvidia.com
Link: http://lkml.kernel.org/r/20190719192955.30462-4-rcampbell@nvidia.com
Fixes: a5430dda8a ("mm/migrate: support un-addressable ZONE_DEVICE page in migration")
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When a ZONE_DEVICE private page is freed, the page->mapping field can be
set. If this page is reused as an anonymous page, the previous value
can prevent the page from being inserted into the CPU's anon rmap table.
For example, when migrating a pte_none() page to device memory:
migrate_vma(ops, vma, start, end, src, dst, private)
migrate_vma_collect()
src[] = MIGRATE_PFN_MIGRATE
migrate_vma_prepare()
/* no page to lock or isolate so OK */
migrate_vma_unmap()
/* no page to unmap so OK */
ops->alloc_and_copy()
/* driver allocates ZONE_DEVICE page for dst[] */
migrate_vma_pages()
migrate_vma_insert_page()
page_add_new_anon_rmap()
__page_set_anon_rmap()
/* This check sees the page's stale mapping field */
if (PageAnon(page))
return
/* page->mapping is not updated */
The result is that the migration appears to succeed but a subsequent CPU
fault will be unable to migrate the page back to system memory or worse.
Clear the page->mapping field when freeing the ZONE_DEVICE page so stale
pointer data doesn't affect future page use.
Link: http://lkml.kernel.org/r/20190719192955.30462-3-rcampbell@nvidia.com
Fixes: b7a523109f ("mm: don't clear ->mapping in hmm_devmem_free")
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Jan Kara <jack@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, attempts to shutdown and re-enable a device-dax instance
trigger:
Missing reference count teardown definition
WARNING: CPU: 37 PID: 1608 at mm/memremap.c:211 devm_memremap_pages+0x234/0x850
[..]
RIP: 0010:devm_memremap_pages+0x234/0x850
[..]
Call Trace:
dev_dax_probe+0x66/0x190 [device_dax]
really_probe+0xef/0x390
driver_probe_device+0xb4/0x100
device_driver_attach+0x4f/0x60
Given that the setup path initializes pgmap->ref, arrange for it to be
also torn down so devm_memremap_pages() is ready to be called again and
not be mistaken for the 3rd-party per-cpu-ref case.
Fixes: 24917f6b10 ("memremap: provide an optional internal refcount in struct dev_pagemap")
Reported-by: Fan Du <fan.du@intel.com>
Tested-by: Vishal Verma <vishal.l.verma@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/156530042781.2068700.8733813683117819799.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Make HMM_MIRROR an option that is selected by drivers wanting to use it
instead of a user visible option as it is just a low-level implementation
detail.
Link: https://lore.kernel.org/r/20190806160554.14046-15-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
There isn't really any architecture specific code in this page table walk
implementation, so drop the dependencies.
Link: https://lore.kernel.org/r/20190806160554.14046-14-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Stub out the whole function and assign NULL to the .hugetlb_entry method
if CONFIG_HUGETLB_PAGE is not set, as the method won't ever be called in
that case.
Link: https://lore.kernel.org/r/20190806160554.14046-13-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Stub out the whole function when CONFIG_TRANSPARENT_HUGEPAGE is not set to
make the function easier to read.
Link: https://lore.kernel.org/r/20190806160554.14046-12-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
We only need the special pud_entry walker if PUD-sized hugepages and pte
mappings are supported, else the common pagewalk code will take care of
the iteration. Not implementing this callback reduced the amount of code
compiled for non-x86 platforms, and also fixes compile failures with other
architectures when helpers like pud_pfn are not implemented.
Link: https://lore.kernel.org/r/20190806160554.14046-11-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
pte_index is an internal arch helper in various architectures, without
consistent semantics. Open code that calculation of a PMD index based on
the virtual address instead.
Link: https://lore.kernel.org/r/20190806160554.14046-10-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
The pagewalk code already passes the value as the hmask parameter.
Link: https://lore.kernel.org/r/20190806160554.14046-9-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
All users pass PAGE_SIZE here, and if we wanted to support single entries
for huge pages we should really just add a HMM_FAULT_HUGEPAGE flag instead
that uses the huge page size instead of having the caller calculate that
size once, just for the hmm code to verify it.
Link: https://lore.kernel.org/r/20190806160554.14046-8-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
The start, end and page_shift values are all saved in the range structure,
so we might as well use that for argument passing.
Link: https://lore.kernel.org/r/20190806160554.14046-7-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
memremap.c implements MM functionality for ZONE_DEVICE, so it really
should be in the mm/ directory, not the kernel/ one.
Link: http://lkml.kernel.org/r/20190722094143.18387-1-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
return is unneeded in void function
Link: http://lkml.kernel.org/r/20190723130814.21826-1-houweitaoo@gmail.com
Signed-off-by: Weitao Hou <houweitaoo@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When CONFIG_MIGRATE_VMA_HELPER is enabled, migrate_vma() calls
migrate_vma_collect() which initializes a struct mm_walk but didn't
initialize mm_walk.pud_entry. (Found by code inspection) Use a C
structure initialization to make sure it is set to NULL.
Link: http://lkml.kernel.org/r/20190719233225.12243-1-rcampbell@nvidia.com
Fixes: 8763cb45ab ("mm/migrate: new memory migration helper for use with device memory")
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Jérôme Glisse" <jglisse@redhat.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
"howaboutsynergy" reported via kernel buzilla number 204165 that
compact_zone_order was consuming 100% CPU during a stress test for
prolonged periods of time. Specifically the following command, which
should exit in 10 seconds, was taking an excessive time to finish while
the CPU was pegged at 100%.
stress -m 220 --vm-bytes 1000000000 --timeout 10
Tracing indicated a pattern as follows
stress-3923 [007] 519.106208: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106212: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106216: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106219: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106223: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106227: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106231: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106235: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106238: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
stress-3923 [007] 519.106242: mm_compaction_isolate_migratepages: range=(0x70bb80 ~ 0x70bb80) nr_scanned=0 nr_taken=0
Note that compaction is entered in rapid succession while scanning and
isolating nothing. The problem is that when a task that is compacting
receives a fatal signal, it retries indefinitely instead of exiting
while making no progress as a fatal signal is pending.
It's not easy to trigger this condition although enabling zswap helps on
the basis that the timing is altered. A very small window has to be hit
for the problem to occur (signal delivered while compacting and
isolating a PFN for migration that is not aligned to SWAP_CLUSTER_MAX).
This was reproduced locally -- 16G single socket system, 8G swap, 30%
zswap configured, vm-bytes 22000000000 using Colin Kings stress-ng
implementation from github running in a loop until the problem hits).
Tracing recorded the problem occurring almost 200K times in a short
window. With this patch, the problem hit 4 times but the task existed
normally instead of consuming CPU.
This problem has existed for some time but it was made worse by commit
cf66f0700c ("mm, compaction: do not consider a need to reschedule as
contention"). Before that commit, if the same condition was hit then
locks would be quickly contended and compaction would exit that way.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204165
Link: http://lkml.kernel.org/r/20190718085708.GE24383@techsingularity.net
Fixes: cf66f0700c ("mm, compaction: do not consider a need to reschedule as contention")
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org> [5.1+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
buffer_migrate_page_norefs() can race with bh users in the following
way:
CPU1 CPU2
buffer_migrate_page_norefs()
buffer_migrate_lock_buffers()
checks bh refs
spin_unlock(&mapping->private_lock)
__find_get_block()
spin_lock(&mapping->private_lock)
grab bh ref
spin_unlock(&mapping->private_lock)
move page do bh work
This can result in various issues like lost updates to buffers (i.e.
metadata corruption) or use after free issues for the old page.
This patch closes the race by holding mapping->private_lock while the
mapping is being moved to a new page. Ordinarily, a reference can be
taken outside of the private_lock using the per-cpu BH LRU but the
references are checked and the LRU invalidated if necessary. The
private_lock is held once the references are known so the buffer lookup
slow path will spin on the private_lock. Between the page lock and
private_lock, it should be impossible for other references to be
acquired and updates to happen during the migration.
A user had reported data corruption issues on a distribution kernel with
a similar page migration implementation as mainline. The data
corruption could not be reproduced with this patch applied. A small
number of migration-intensive tests were run and no performance problems
were noted.
[mgorman@techsingularity.net: Changelog, removed tracing]
Link: http://lkml.kernel.org/r/20190718090238.GF24383@techsingularity.net
Fixes: 89cb0888ca "mm: migrate: provide buffer_migrate_page_norefs()"
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org> [5.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Shakeel Butt reported premature oom on kernel with
"cgroup_disable=memory" since mem_cgroup_is_root() returns false even
though memcg is actually NULL. The drop_caches is also broken.
It is because commit aeed1d325d ("mm/vmscan.c: generalize
shrink_slab() calls in shrink_node()") removed the !memcg check before
!mem_cgroup_is_root(). And, surprisingly root memcg is allocated even
though memory cgroup is disabled by kernel boot parameter.
Add mem_cgroup_disabled() check to make reclaimer work as expected.
Link: http://lkml.kernel.org/r/1563385526-20805-1-git-send-email-yang.shi@linux.alibaba.com
Fixes: aeed1d325d ("mm/vmscan.c: generalize shrink_slab() calls in shrink_node()")
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Reported-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Jan Hadrava <had@kam.mff.cuni.cz>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org> [4.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When running ltp's oom test with kmemleak enabled, the below warning was
triggerred since kernel detects __GFP_NOFAIL & ~__GFP_DIRECT_RECLAIM is
passed in:
WARNING: CPU: 105 PID: 2138 at mm/page_alloc.c:4608 __alloc_pages_nodemask+0x1c31/0x1d50
Modules linked in: loop dax_pmem dax_pmem_core ip_tables x_tables xfs virtio_net net_failover virtio_blk failover ata_generic virtio_pci virtio_ring virtio libata
CPU: 105 PID: 2138 Comm: oom01 Not tainted 5.2.0-next-20190710+ #7
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
RIP: 0010:__alloc_pages_nodemask+0x1c31/0x1d50
...
kmemleak_alloc+0x4e/0xb0
kmem_cache_alloc+0x2a7/0x3e0
mempool_alloc_slab+0x2d/0x40
mempool_alloc+0x118/0x2b0
bio_alloc_bioset+0x19d/0x350
get_swap_bio+0x80/0x230
__swap_writepage+0x5ff/0xb20
The mempool_alloc_slab() clears __GFP_DIRECT_RECLAIM, however kmemleak
has __GFP_NOFAIL set all the time due to d9570ee3bd ("kmemleak:
allow to coexist with fault injection"). But, it doesn't make any sense
to have __GFP_NOFAIL and ~__GFP_DIRECT_RECLAIM specified at the same
time.
According to the discussion on the mailing list, the commit should be
reverted for short term solution. Catalin Marinas would follow up with
a better solution for longer term.
The failure rate of kmemleak metadata allocation may increase in some
circumstances, but this should be expected side effect.
Link: http://lkml.kernel.org/r/1563299431-111710-1-git-send-email-yang.shi@linux.alibaba.com
Fixes: d9570ee3bd ("kmemleak: allow to coexist with fault injection")
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To properly clear the slab on free with slab_want_init_on_free, we walk
the list of free objects using get_freepointer/set_freepointer.
The value we get from get_freepointer may not be valid. This isn't an
issue since an actual value will get written later but this means
there's a chance of triggering a bug if we use this value with
set_freepointer:
kernel BUG at mm/slub.c:306!
invalid opcode: 0000 [#1] PREEMPT PTI
CPU: 0 PID: 0 Comm: swapper Not tainted 5.2.0-05754-g6471384a #4
RIP: 0010:kfree+0x58a/0x5c0
Code: 48 83 05 78 37 51 02 01 0f 0b 48 83 05 7e 37 51 02 01 48 83 05 7e 37 51 02 01 48 83 05 7e 37 51 02 01 48 83 05 d6 37 51 02 01 <0f> 0b 48 83 05 d4 37 51 02 01 48 83 05 d4 37 51 02 01 48 83 05 d4
RSP: 0000:ffffffff82603d90 EFLAGS: 00010002
RAX: ffff8c3976c04320 RBX: ffff8c3976c04300 RCX: 0000000000000000
RDX: ffff8c3976c04300 RSI: 0000000000000000 RDI: ffff8c3976c04320
RBP: ffffffff82603db8 R08: 0000000000000000 R09: 0000000000000000
R10: ffff8c3976c04320 R11: ffffffff8289e1e0 R12: ffffd52cc8db0100
R13: ffff8c3976c01a00 R14: ffffffff810f10d4 R15: ffff8c3976c04300
FS: 0000000000000000(0000) GS:ffffffff8266b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff8c397ffff000 CR3: 0000000125020000 CR4: 00000000000406b0
Call Trace:
apply_wqattrs_prepare+0x154/0x280
apply_workqueue_attrs_locked+0x4e/0xe0
apply_workqueue_attrs+0x36/0x60
alloc_workqueue+0x25a/0x6d0
workqueue_init_early+0x246/0x348
start_kernel+0x3c7/0x7ec
x86_64_start_reservations+0x40/0x49
x86_64_start_kernel+0xda/0xe4
secondary_startup_64+0xb6/0xc0
Modules linked in:
---[ end trace f67eb9af4d8d492b ]---
Fix this by ensuring the value we set with set_freepointer is either NULL
or another value in the chain.
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Fixes: 6471384af2 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix the locking around nouveau's use of the hmm_range_* APIs. It works
correctly in the success case, but many of the the edge cases have missing
unlocks or double unlocks.
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Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull HMM fixes from Jason Gunthorpe:
"Fix the locking around nouveau's use of the hmm_range_* APIs. It works
correctly in the success case, but many of the the edge cases have
missing unlocks or double unlocks.
The diffstat is a bit big as Christoph did a comprehensive job to move
the obsolete API from the core header and into the driver before
fixing its flow, but the risk of regression from this code motion is
low"
* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma:
nouveau: unlock mmap_sem on all errors from nouveau_range_fault
nouveau: remove the block parameter to nouveau_range_fault
mm/hmm: move hmm_vma_range_done and hmm_vma_fault to nouveau
mm/hmm: always return EBUSY for invalid ranges in hmm_range_{fault,snapshot}
Fixes in the iommu and balloon devices.
Disable the meta-data optimization for now - I hope we can get it fixed
shortly, but there's no point in making users suffer crashes while we
are working on that.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio/vhost fixes from Michael Tsirkin:
- Fixes in the iommu and balloon devices.
- Disable the meta-data optimization for now - I hope we can get it
fixed shortly, but there's no point in making users suffer crashes
while we are working on that.
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
vhost: disable metadata prefetch optimization
iommu/virtio: Update to most recent specification
balloon: fix up comments
mm/balloon_compaction: avoid duplicate page removal
Since hmm_range_fault() doesn't use the struct hmm_range vma field, remove
it.
Link: https://lore.kernel.org/r/20190726005650.2566-8-rcampbell@nvidia.com
Suggested-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
walk_page_range() will only call hmm_vma_walk_hugetlb_entry() for
hugetlbfs pages and doesn't call hmm_vma_walk_pmd() in this case.
Therefore, it is safe to remove the check for vma->vm_flags & VM_HUGETLB
in hmm_vma_walk_pmd().
Link: https://lore.kernel.org/r/20190726005650.2566-7-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Add a HMM_FAULT_SNAPSHOT flag so that hmm_range_snapshot can be merged
into the almost identical hmm_range_fault function.
Link: https://lore.kernel.org/r/20190726005650.2566-5-rcampbell@nvidia.com
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This allows easier expansion to other flags, and also makes the callers a
little easier to read.
Link: https://lore.kernel.org/r/20190726005650.2566-4-rcampbell@nvidia.com
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
A few more comments and minor programming style clean ups. There should
be no functional changes.
Link: https://lore.kernel.org/r/20190726005650.2566-3-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
The hmm_mirror_ops callback function sync_cpu_device_pagetables() passes a
struct hmm_update which is a simplified version of struct
mmu_notifier_range. This is unnecessary so replace hmm_update with
mmu_notifier_range directly.
Link: https://lore.kernel.org/r/20190726005650.2566-2-rcampbell@nvidia.com
Signed-off-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
[jgg: white space tuning]
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
The magic dropping of mmap_sem when handle_mm_fault returns VM_FAULT_RETRY
is rather subtile. Add a comment explaining it.
Link: https://lore.kernel.org/r/20190724065258.16603-8-hch@lst.de
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
[hch: wrote a changelog]
Signed-off-by: Christoph Hellwig <hch@lst.de>
We should not have two different error codes for the same
condition. EAGAIN must be reserved for the FAULT_FLAG_ALLOW_RETRY retry
case and signals to the caller that the mmap_sem has been unlocked.
Use EBUSY for the !valid case so that callers can get the locking right.
Link: https://lore.kernel.org/r/20190724065258.16603-2-hch@lst.de
Tested-by: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
[jgg: elaborated commit message]
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Lots of comments bitrotted. Fix them up.
Fixes: 418a3ab1e7 (mm/balloon_compaction: List interfaces)
Reviewed-by: Wei Wang <wei.w.wang@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Acked-by: Nadav Amit <namit@vmware.com>
A #GP is reported in the guest when requesting balloon inflation via
virtio-balloon. The reason is that the virtio-balloon driver has
removed the page from its internal page list (via balloon_page_pop),
but balloon_page_enqueue_one also calls "list_del" to do the removal.
This is necessary when it's used from balloon_page_enqueue_list, but
not from balloon_page_enqueue.
Move list_del to balloon_page_enqueue, and update comments accordingly.
Fixes: 418a3ab1e7 (mm/balloon_compaction: List interfaces)
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
On x86-32 with PTI enabled, parts of the kernel page-tables are not shared
between processes. This can cause mappings in the vmalloc/ioremap area to
persist in some page-tables after the region is unmapped and released.
When the region is re-used the processes with the old mappings do not fault
in the new mappings but still access the old ones.
This causes undefined behavior, in reality often data corruption, kernel
oopses and panics and even spontaneous reboots.
Fix this problem by activly syncing unmaps in the vmalloc/ioremap area to
all page-tables in the system before the regions can be re-used.
References: https://bugzilla.suse.com/show_bug.cgi?id=1118689
Fixes: 5d72b4fba4 ('x86, mm: support huge I/O mapping capability I/F')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20190719184652.11391-4-joro@8bytes.org
Pull vfs mount updates from Al Viro:
"The first part of mount updates.
Convert filesystems to use the new mount API"
* 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
mnt_init(): call shmem_init() unconditionally
constify ksys_mount() string arguments
don't bother with registering rootfs
init_rootfs(): don't bother with init_ramfs_fs()
vfs: Convert smackfs to use the new mount API
vfs: Convert selinuxfs to use the new mount API
vfs: Convert securityfs to use the new mount API
vfs: Convert apparmorfs to use the new mount API
vfs: Convert openpromfs to use the new mount API
vfs: Convert xenfs to use the new mount API
vfs: Convert gadgetfs to use the new mount API
vfs: Convert oprofilefs to use the new mount API
vfs: Convert ibmasmfs to use the new mount API
vfs: Convert qib_fs/ipathfs to use the new mount API
vfs: Convert efivarfs to use the new mount API
vfs: Convert configfs to use the new mount API
vfs: Convert binfmt_misc to use the new mount API
convenience helper: get_tree_single()
convenience helper get_tree_nodev()
vfs: Kill sget_userns()
...
Merge yet more updates from Andrew Morton:
"The rest of MM and a kernel-wide procfs cleanup.
Summary of the more significant patches:
- Patch series "mm/memory_hotplug: Factor out memory block
devicehandling", v3. David Hildenbrand.
Some spring-cleaning of the memory hotplug code, notably in
drivers/base/memory.c
- "mm: thp: fix false negative of shmem vma's THP eligibility". Yang
Shi.
Fix /proc/pid/smaps output for THP pages used in shmem.
- "resource: fix locking in find_next_iomem_res()" + 1. Nadav Amit.
Bugfix and speedup for kernel/resource.c
- Patch series "mm: Further memory block device cleanups", David
Hildenbrand.
More spring-cleaning of the memory hotplug code.
- Patch series "mm: Sub-section memory hotplug support". Dan
Williams.
Generalise the memory hotplug code so that pmem can use it more
completely. Then remove the hacks from the libnvdimm code which
were there to work around the memory-hotplug code's constraints.
- "proc/sysctl: add shared variables for range check", Matteo Croce.
We have about 250 instances of
int zero;
...
.extra1 = &zero,
in the tree. This is a tree-wide sweep to make all those private
"zero"s and "one"s use global variables.
Alas, it isn't practical to make those two global integers const"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (38 commits)
proc/sysctl: add shared variables for range check
mm: migrate: remove unused mode argument
mm/sparsemem: cleanup 'section number' data types
libnvdimm/pfn: stop padding pmem namespaces to section alignment
libnvdimm/pfn: fix fsdax-mode namespace info-block zero-fields
mm/devm_memremap_pages: enable sub-section remap
mm: document ZONE_DEVICE memory-model implications
mm/sparsemem: support sub-section hotplug
mm/sparsemem: prepare for sub-section ranges
mm: kill is_dev_zone() helper
mm/hotplug: kill is_dev_zone() usage in __remove_pages()
mm/sparsemem: convert kmalloc_section_memmap() to populate_section_memmap()
mm/hotplug: prepare shrink_{zone, pgdat}_span for sub-section removal
mm/sparsemem: add helpers track active portions of a section at boot
mm/sparsemem: introduce a SECTION_IS_EARLY flag
mm/sparsemem: introduce struct mem_section_usage
drivers/base/memory.c: get rid of find_memory_block_hinted()
mm/memory_hotplug: move and simplify walk_memory_blocks()
mm/memory_hotplug: rename walk_memory_range() and pass start+size instead of pfns
mm: make register_mem_sect_under_node() static
...
migrate_page_move_mapping() doesn't use the mode argument. Remove it
and update callers accordingly.
Link: http://lkml.kernel.org/r/20190508210301.8472-1-keith.busch@intel.com
Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
David points out that there is a mixture of 'int' and 'unsigned long'
usage for section number data types. Update the memory hotplug path to
use 'unsigned long' consistently for section numbers.
[akpm@linux-foundation.org: fix printk format]
Link: http://lkml.kernel.org/r/156107543656.1329419.11505835211949439815.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: David Hildenbrand <david@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The libnvdimm sub-system has suffered a series of hacks and broken
workarounds for the memory-hotplug implementation's awkward
section-aligned (128MB) granularity.
For example the following backtrace is emitted when attempting
arch_add_memory() with physical address ranges that intersect 'System
RAM' (RAM) with 'Persistent Memory' (PMEM) within a given section:
# cat /proc/iomem | grep -A1 -B1 Persistent\ Memory
100000000-1ffffffff : System RAM
200000000-303ffffff : Persistent Memory (legacy)
304000000-43fffffff : System RAM
440000000-23ffffffff : Persistent Memory
2400000000-43bfffffff : Persistent Memory
2400000000-43bfffffff : namespace2.0
WARNING: CPU: 38 PID: 928 at arch/x86/mm/init_64.c:850 add_pages+0x5c/0x60
[..]
RIP: 0010:add_pages+0x5c/0x60
[..]
Call Trace:
devm_memremap_pages+0x460/0x6e0
pmem_attach_disk+0x29e/0x680 [nd_pmem]
? nd_dax_probe+0xfc/0x120 [libnvdimm]
nvdimm_bus_probe+0x66/0x160 [libnvdimm]
It was discovered that the problem goes beyond RAM vs PMEM collisions as
some platform produce PMEM vs PMEM collisions within a given section.
The libnvdimm workaround for that case revealed that the libnvdimm
section-alignment-padding implementation has been broken for a long
while.
A fix for that long-standing breakage introduces as many problems as it
solves as it would require a backward-incompatible change to the
namespace metadata interpretation. Instead of that dubious route [1],
address the root problem in the memory-hotplug implementation.
Note that EEXIST is no longer treated as success as that is how
sparse_add_section() reports subsection collisions, it was also obviated
by recent changes to perform the request_region() for 'System RAM'
before arch_add_memory() in the add_memory() sequence.
[1] https://lore.kernel.org/r/155000671719.348031.2347363160141119237.stgit@dwillia2-desk3.amr.corp.intel.com
[osalvador@suse.de: fix deactivate_section for early sections]
Link: http://lkml.kernel.org/r/20190715081549.32577-2-osalvador@suse.de
Link: http://lkml.kernel.org/r/156092354368.979959.6232443923440952359.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64]
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Prepare the memory hot-{add,remove} paths for handling sub-section
ranges by plumbing the starting page frame and number of pages being
handled through arch_{add,remove}_memory() to
sparse_{add,remove}_one_section().
This is simply plumbing, small cleanups, and some identifier renames.
No intended functional changes.
Link: http://lkml.kernel.org/r/156092353780.979959.9713046515562743194.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64]
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Given there are no more usages of is_dev_zone() outside of 'ifdef
CONFIG_ZONE_DEVICE' protection, kill off the compilation helper.
Link: http://lkml.kernel.org/r/156092353211.979959.1489004866360828964.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64]
Cc: Michal Hocko <mhocko@suse.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The zone type check was a leftover from the cleanup that plumbed altmap
through the memory hotplug path, i.e. commit da024512a1 "mm: pass the
vmem_altmap to arch_remove_memory and __remove_pages".
Link: http://lkml.kernel.org/r/156092352642.979959.6664333788149363039.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64]
Cc: Michal Hocko <mhocko@suse.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow sub-section sized ranges to be added to the memmap.
populate_section_memmap() takes an explict pfn range rather than
assuming a full section, and those parameters are plumbed all the way
through to vmmemap_populate(). There should be no sub-section usage in
current deployments. New warnings are added to clarify which memmap
allocation paths are sub-section capable.
Link: http://lkml.kernel.org/r/156092352058.979959.6551283472062305149.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64]
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sub-section hotplug support reduces the unit of operation of hotplug
from section-sized-units (PAGES_PER_SECTION) to sub-section-sized units
(PAGES_PER_SUBSECTION). Teach shrink_{zone,pgdat}_span() to consider
PAGES_PER_SUBSECTION boundaries as the points where pfn_valid(), not
valid_section(), can toggle.
[osalvador@suse.de: fix shrink_{zone,node}_span]
Link: http://lkml.kernel.org/r/20190717090725.23618-3-osalvador@suse.de
Link: http://lkml.kernel.org/r/156092351496.979959.12703722803097017492.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64]
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Prepare for hot{plug,remove} of sub-ranges of a section by tracking a
sub-section active bitmask, each bit representing a PMD_SIZE span of the
architecture's memory hotplug section size.
The implications of a partially populated section is that pfn_valid()
needs to go beyond a valid_section() check and either determine that the
section is an "early section", or read the sub-section active ranges
from the bitmask. The expectation is that the bitmask (subsection_map)
fits in the same cacheline as the valid_section() / early_section()
data, so the incremental performance overhead to pfn_valid() should be
negligible.
The rationale for using early_section() to short-ciruit the
subsection_map check is that there are legacy code paths that use
pfn_valid() at section granularity before validating the pfn against
pgdat data. So, the early_section() check allows those traditional
assumptions to persist while also permitting subsection_map to tell the
truth for purposes of populating the unused portions of early sections
with PMEM and other ZONE_DEVICE mappings.
Link: http://lkml.kernel.org/r/156092350874.979959.18185938451405518285.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Qian Cai <cai@lca.pw>
Tested-by: Jane Chu <jane.chu@oracle.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64]
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In preparation for sub-section hotplug, track whether a given section
was created during early memory initialization, or later via memory
hotplug. This distinction is needed to maintain the coarse expectation
that pfn_valid() returns true for any pfn within a given section even if
that section has pages that are reserved from the page allocator.
For example one of the of goals of subsection hotplug is to support
cases where the system physical memory layout collides System RAM and
PMEM within a section. Several pfn_valid() users expect to just check
if a section is valid, but they are not careful to check if the given
pfn is within a "System RAM" boundary and instead expect pgdat
information to further validate the pfn.
Rather than unwind those paths to make their pfn_valid() queries more
precise a follow on patch uses the SECTION_IS_EARLY flag to maintain the
traditional expectation that pfn_valid() returns true for all early
sections.
Link: https://lore.kernel.org/lkml/1560366952-10660-1-git-send-email-cai@lca.pw/
Link: http://lkml.kernel.org/r/156092350358.979959.5817209875548072819.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Qian Cai <cai@lca.pw>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64]
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: Sub-section memory hotplug support", v10.
The memory hotplug section is an arbitrary / convenient unit for memory
hotplug. 'Section-size' units have bled into the user interface
('memblock' sysfs) and can not be changed without breaking existing
userspace. The section-size constraint, while mostly benign for typical
memory hotplug, has and continues to wreak havoc with 'device-memory'
use cases, persistent memory (pmem) in particular. Recall that pmem
uses devm_memremap_pages(), and subsequently arch_add_memory(), to
allocate a 'struct page' memmap for pmem. However, it does not use the
'bottom half' of memory hotplug, i.e. never marks pmem pages online and
never exposes the userspace memblock interface for pmem. This leaves an
opening to redress the section-size constraint.
To date, the libnvdimm subsystem has attempted to inject padding to
satisfy the internal constraints of arch_add_memory(). Beyond
complicating the code, leading to bugs [2], wasting memory, and limiting
configuration flexibility, the padding hack is broken when the platform
changes this physical memory alignment of pmem from one boot to the
next. Device failure (intermittent or permanent) and physical
reconfiguration are events that can cause the platform firmware to
change the physical placement of pmem on a subsequent boot, and device
failure is an everyday event in a data-center.
It turns out that sections are only a hard requirement of the
user-facing interface for memory hotplug and with a bit more
infrastructure sub-section arch_add_memory() support can be added for
kernel internal usages like devm_memremap_pages(). Here is an analysis
of the current design assumptions in the current code and how they are
addressed in the new implementation:
Current design assumptions:
- Sections that describe boot memory (early sections) are never
unplugged / removed.
- pfn_valid(), in the CONFIG_SPARSEMEM_VMEMMAP=y, case devolves to a
valid_section() check
- __add_pages() and helper routines assume all operations occur in
PAGES_PER_SECTION units.
- The memblock sysfs interface only comprehends full sections
New design assumptions:
- Sections are instrumented with a sub-section bitmask to track (on
x86) individual 2MB sub-divisions of a 128MB section.
- Partially populated early sections can be extended with additional
sub-sections, and those sub-sections can be removed with
arch_remove_memory(). With this in place we no longer lose usable
memory capacity to padding.
- pfn_valid() is updated to look deeper than valid_section() to also
check the active-sub-section mask. This indication is in the same
cacheline as the valid_section() so the performance impact is
expected to be negligible. So far the lkp robot has not reported any
regressions.
- Outside of the core vmemmap population routines which are replaced,
other helper routines like shrink_{zone,pgdat}_span() are updated to
handle the smaller granularity. Core memory hotplug routines that
deal with online memory are not touched.
- The existing memblock sysfs user api guarantees / assumptions are not
touched since this capability is limited to !online
!memblock-sysfs-accessible sections.
Meanwhile the issue reports continue to roll in from users that do not
understand when and how the 128MB constraint will bite them. The current
implementation relied on being able to support at least one misaligned
namespace, but that immediately falls over on any moderately complex
namespace creation attempt. Beyond the initial problem of 'System RAM'
colliding with pmem, and the unsolvable problem of physical alignment
changes, Linux is now being exposed to platforms that collide pmem ranges
with other pmem ranges by default [3]. In short, devm_memremap_pages()
has pushed the venerable section-size constraint past the breaking point,
and the simplicity of section-aligned arch_add_memory() is no longer
tenable.
These patches are exposed to the kbuild robot on a subsection-v10 branch
[4], and a preview of the unit test for this functionality is available
on the 'subsection-pending' branch of ndctl [5].
[2]: https://lore.kernel.org/r/155000671719.348031.2347363160141119237.stgit@dwillia2-desk3.amr.corp.intel.com
[3]: https://github.com/pmem/ndctl/issues/76
[4]: https://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm.git/log/?h=subsection-v10
[5]: https://github.com/pmem/ndctl/commit/7c59b4867e1c
This patch (of 13):
Towards enabling memory hotplug to track partial population of a section,
introduce 'struct mem_section_usage'.
A pointer to a 'struct mem_section_usage' instance replaces the existing
pointer to a 'pageblock_flags' bitmap. Effectively it adds one more
'unsigned long' beyond the 'pageblock_flags' (usemap) allocation to house
a new 'subsection_map' bitmap. The new bitmap enables the memory
hot{plug,remove} implementation to act on incremental sub-divisions of a
section.
SUBSECTION_SHIFT is defined as global constant instead of per-architecture
value like SECTION_SIZE_BITS in order to allow cross-arch compatibility of
subsection users. Specifically a common subsection size allows for the
possibility that persistent memory namespace configurations be made
compatible across architectures.
The primary motivation for this functionality is to support platforms that
mix "System RAM" and "Persistent Memory" within a single section, or
multiple PMEM ranges with different mapping lifetimes within a single
section. The section restriction for hotplug has caused an ongoing saga
of hacks and bugs for devm_memremap_pages() users.
Beyond the fixups to teach existing paths how to retrieve the 'usemap'
from a section, and updates to usemap allocation path, there are no
expected behavior changes.
Link: http://lkml.kernel.org/r/156092349845.979959.73333291612799019.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [ppc64]
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Qian Cai <cai@lca.pw>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let's move walk_memory_blocks() to the place where memory block logic
resides and simplify it. While at it, add a type for the callback
function.
Link: http://lkml.kernel.org/r/20190614100114.311-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
walk_memory_range() was once used to iterate over sections. Now, it
iterates over memory blocks. Rename the function, fixup the
documentation.
Also, pass start+size instead of PFNs, which is what most callers
already have at hand. (we'll rework link_mem_sections() most probably
soon)
Follow-up patches will rework, simplify, and move walk_memory_blocks()
to drivers/base/memory.c.
Note: walk_memory_blocks() only works correctly right now if the
start_pfn is aligned to a section start. This is the case right now,
but we'll generalize the function in a follow up patch so the semantics
match the documentation.
[akpm@linux-foundation.org: remove unused variable]
Link: http://lkml.kernel.org/r/20190614100114.311-5-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Rashmica Gupta <rashmica.g@gmail.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: Further memory block device cleanups", v1.
Some further cleanups around memory block devices. Especially, clean up
and simplify walk_memory_range(). Including some other minor cleanups.
This patch (of 6):
We are using a mixture of "int" and "unsigned long". Let's make this
consistent by using "unsigned long" everywhere. We'll do the same with
memory block ids next.
While at it, turn the "unsigned long i" in removable_show() into an int
- sections_per_block is an int.
[akpm@linux-foundation.org: s/unsigned long i/unsigned long nr/]
[david@redhat.com: v3]
Link: http://lkml.kernel.org/r/20190620183139.4352-2-david@redhat.com
Link: http://lkml.kernel.org/r/20190614100114.311-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 7635d9cbe8 ("mm, thp, proc: report THP eligibility for each
vma") introduced THPeligible bit for processes' smaps. But, when
checking the eligibility for shmem vma, __transparent_hugepage_enabled()
is called to override the result from shmem_huge_enabled(). It may
result in the anonymous vma's THP flag override shmem's. For example,
running a simple test which create THP for shmem, but with anonymous THP
disabled, when reading the process's smaps, it may show:
7fc92ec00000-7fc92f000000 rw-s 00000000 00:14 27764 /dev/shm/test
Size: 4096 kB
...
[snip]
...
ShmemPmdMapped: 4096 kB
...
[snip]
...
THPeligible: 0
And, /proc/meminfo does show THP allocated and PMD mapped too:
ShmemHugePages: 4096 kB
ShmemPmdMapped: 4096 kB
This doesn't make too much sense. The shmem objects should be treated
separately from anonymous THP. Calling shmem_huge_enabled() with
checking MMF_DISABLE_THP sounds good enough. And, we could skip stack
and dax vma check since we already checked if the vma is shmem already.
Also check if vma is suitable for THP by calling
transhuge_vma_suitable().
And minor fix to smaps output format and documentation.
Link: http://lkml.kernel.org/r/1560401041-32207-3-git-send-email-yang.shi@linux.alibaba.com
Fixes: 7635d9cbe8 ("mm, thp, proc: report THP eligibility for each vma")
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
transhuge_vma_suitable() was only available for shmem THP, but anonymous
THP has the same check except pgoff check. And, it will be used for THP
eligible check in the later patch, so make it available for all kind of
THPs. This also helps reduce code duplication slightly.
Since anonymous THP doesn't have to check pgoff, so make pgoff check
shmem vma only.
And regroup some functions in include/linux/mm.h to solve compile issue
since transhuge_vma_suitable() needs call vma_is_anonymous() which was
defined after huge_mm.h is included.
[akpm@linux-foundation.org: fix typo]
[yang.shi@linux.alibaba.com: v4]
Link: http://lkml.kernel.org/r/1563400758-124759-2-git-send-email-yang.shi@linux.alibaba.com
Link: http://lkml.kernel.org/r/1560401041-32207-2-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In case of NODE_NOT_IN_PAGE_FLAGS is set, we store section's node id in
section_to_node_table[]. While for hot-add memory, this is missed.
Without this information, page_to_nid() may not give the right node id.
BTW, current online_pages works because it leverages nid in
memory_block. But the granularity of node id should be mem_section
wide.
Link: http://lkml.kernel.org/r/20190618005537.18878-1-richardw.yang@linux.intel.com
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The parameter is unused, so let's drop it. Memory removal paths should
never care about zones. This is the job of memory offlining and will
require more refactorings.
Link: http://lkml.kernel.org/r/20190527111152.16324-12-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jun Yao <yaojun8558363@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let's factor out removing of memory block devices, which is only
necessary for memory added via add_memory() and friends that created
memory block devices. Remove the devices before calling
arch_remove_memory().
This finishes factoring out memory block device handling from
arch_add_memory() and arch_remove_memory().
Link: http://lkml.kernel.org/r/20190527111152.16324-10-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Mark Brown <broonie@kernel.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jun Yao <yaojun8558363@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
No longer needed, the callers of arch_add_memory() can handle this
manually.
Link: http://lkml.kernel.org/r/20190527111152.16324-9-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jun Yao <yaojun8558363@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Only memory to be added to the buddy and to be onlined/offlined by user
space using /sys/devices/system/memory/... needs (and should have!)
memory block devices.
Factor out creation of memory block devices. Create all devices after
arch_add_memory() succeeded. We can later drop the want_memblock
parameter, because it is now effectively stale.
Only after memory block devices have been added, memory can be onlined
by user space. This implies, that memory is not visible to user space
at all before arch_add_memory() succeeded.
While at it
- use WARN_ON_ONCE instead of BUG_ON in moved unregister_memory()
- introduce find_memory_block_by_id() to search via block id
- Use find_memory_block_by_id() in init_memory_block() to catch
duplicates
Link: http://lkml.kernel.org/r/20190527111152.16324-8-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Qian Cai <cai@lca.pw>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jun Yao <yaojun8558363@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We want to improve error handling while adding memory by allowing to use
arch_remove_memory() and __remove_pages() even if
CONFIG_MEMORY_HOTREMOVE is not set to e.g., implement something like:
arch_add_memory()
rc = do_something();
if (rc) {
arch_remove_memory();
}
We won't get rid of CONFIG_MEMORY_HOTREMOVE for now, as it will require
quite some dependencies for memory offlining.
Link: http://lkml.kernel.org/r/20190527111152.16324-7-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Oscar Salvador <osalvador@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Mark Brown <broonie@kernel.org>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Qian Cai <cai@lca.pw>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jun Yao <yaojun8558363@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/memory_hotplug: Factor out memory block devicehandling", v3.
We only want memory block devices for memory to be onlined/offlined
(add/remove from the buddy). This is required so user space can
online/offline memory and kdump gets notified about newly onlined
memory.
Let's factor out creation/removal of memory block devices. This helps
to further cleanup arch_add_memory/arch_remove_memory() and to make
implementation of new features easier - especially sub-section memory
hot add from Dan.
Anshuman Khandual is currently working on arch_remove_memory(). I added
a temporary solution via "arm64/mm: Add temporary arch_remove_memory()
implementation", that is sufficient as a firsts tep in the context of
this series. (we don't cleanup page tables in case anything goes wrong
already)
Did a quick sanity test with DIMM plug/unplug, making sure all devices
and sysfs links properly get added/removed. Compile tested on s390x and
x86-64.
This patch (of 11):
By converting start and size to page granularity, we actually ignore
unaligned parts within a page instead of properly bailing out with an
error.
Link: http://lkml.kernel.org/r/20190527111152.16324-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Qian Cai <cai@lca.pw>
Cc: Arun KS <arunks@codeaurora.org>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Andrew Banman <andrew.banman@hpe.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Jun Yao <yaojun8558363@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "mike.travis@hpe.com" <mike.travis@hpe.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Add user space specific memory reading for kprobes
- Allow kprobes to be executed earlier in boot
The rest are mostly just various clean ups and small fixes.
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Merge tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing updates from Steven Rostedt:
"The main changes in this release include:
- Add user space specific memory reading for kprobes
- Allow kprobes to be executed earlier in boot
The rest are mostly just various clean ups and small fixes"
* tag 'trace-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits)
tracing: Make trace_get_fields() global
tracing: Let filter_assign_type() detect FILTER_PTR_STRING
tracing: Pass type into tracing_generic_entry_update()
ftrace/selftest: Test if set_event/ftrace_pid exists before writing
ftrace/selftests: Return the skip code when tracing directory not configured in kernel
tracing/kprobe: Check registered state using kprobe
tracing/probe: Add trace_event_call accesses APIs
tracing/probe: Add probe event name and group name accesses APIs
tracing/probe: Add trace flag access APIs for trace_probe
tracing/probe: Add trace_event_file access APIs for trace_probe
tracing/probe: Add trace_event_call register API for trace_probe
tracing/probe: Add trace_probe init and free functions
tracing/uprobe: Set print format when parsing command
tracing/kprobe: Set print format right after parsed command
kprobes: Fix to init kprobes in subsys_initcall
tracepoint: Use struct_size() in kmalloc()
ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS
ftrace: Enable trampoline when rec count returns back to one
tracing/kprobe: Do not run kprobe boot tests if kprobe_event is on cmdline
tracing: Make a separate config for trace event self tests
...
Merge more updates from Andrew Morton:
"VM:
- z3fold fixes and enhancements by Henry Burns and Vitaly Wool
- more accurate reclaimed slab caches calculations by Yafang Shao
- fix MAP_UNINITIALIZED UAPI symbol to not depend on config, by
Christoph Hellwig
- !CONFIG_MMU fixes by Christoph Hellwig
- new novmcoredd parameter to omit device dumps from vmcore, by
Kairui Song
- new test_meminit module for testing heap and pagealloc
initialization, by Alexander Potapenko
- ioremap improvements for huge mappings, by Anshuman Khandual
- generalize kprobe page fault handling, by Anshuman Khandual
- device-dax hotplug fixes and improvements, by Pavel Tatashin
- enable synchronous DAX fault on powerpc, by Aneesh Kumar K.V
- add pte_devmap() support for arm64, by Robin Murphy
- unify locked_vm accounting with a helper, by Daniel Jordan
- several misc fixes
core/lib:
- new typeof_member() macro including some users, by Alexey Dobriyan
- make BIT() and GENMASK() available in asm, by Masahiro Yamada
- changed LIST_POISON2 on x86_64 to 0xdead000000000122 for better
code generation, by Alexey Dobriyan
- rbtree code size optimizations, by Michel Lespinasse
- convert struct pid count to refcount_t, by Joel Fernandes
get_maintainer.pl:
- add --no-moderated switch to skip moderated ML's, by Joe Perches
misc:
- ptrace PTRACE_GET_SYSCALL_INFO interface
- coda updates
- gdb scripts, various"
[ Using merge message suggestion from Vlastimil Babka, with some editing - Linus ]
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (100 commits)
fs/select.c: use struct_size() in kmalloc()
mm: add account_locked_vm utility function
arm64: mm: implement pte_devmap support
mm: introduce ARCH_HAS_PTE_DEVMAP
mm: clean up is_device_*_page() definitions
mm/mmap: move common defines to mman-common.h
mm: move MAP_SYNC to asm-generic/mman-common.h
device-dax: "Hotremove" persistent memory that is used like normal RAM
mm/hotplug: make remove_memory() interface usable
device-dax: fix memory and resource leak if hotplug fails
include/linux/lz4.h: fix spelling and copy-paste errors in documentation
ipc/mqueue.c: only perform resource calculation if user valid
include/asm-generic/bug.h: fix "cut here" for WARN_ON for __WARN_TAINT architectures
scripts/gdb: add helpers to find and list devices
scripts/gdb: add lx-genpd-summary command
drivers/pps/pps.c: clear offset flags in PPS_SETPARAMS ioctl
kernel/pid.c: convert struct pid count to refcount_t
drivers/rapidio/devices/rio_mport_cdev.c: NUL terminate some strings
select: shift restore_saved_sigmask_unless() into poll_select_copy_remaining()
select: change do_poll() to return -ERESTARTNOHAND rather than -EINTR
...
locked_vm accounting is done roughly the same way in five places, so
unify them in a helper.
Include the helper's caller in the debug print to distinguish between
callsites.
Error codes stay the same, so user-visible behavior does too. The one
exception is that the -EPERM case in tce_account_locked_vm is removed
because Alexey has never seen it triggered.
[daniel.m.jordan@oracle.com: v3]
Link: http://lkml.kernel.org/r/20190529205019.20927-1-daniel.m.jordan@oracle.com
[sfr@canb.auug.org.au: fix mm/util.c]
Link: http://lkml.kernel.org/r/20190524175045.26897-1-daniel.m.jordan@oracle.com
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Cc: Alan Tull <atull@kernel.org>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Moritz Fischer <mdf@kernel.org>
Cc: Paul Mackerras <paulus@ozlabs.org>
Cc: Steve Sistare <steven.sistare@oracle.com>
Cc: Wu Hao <hao.wu@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ARCH_HAS_ZONE_DEVICE is somewhat meaningless in itself, and combined
with the long-out-of-date comment can lead to the impression than an
architecture may just enable it (since __add_pages() now "comprehends
device memory" for itself) and expect things to work.
In practice, however, ZONE_DEVICE users have little chance of
functioning correctly without __HAVE_ARCH_PTE_DEVMAP, so let's clean
that up the same way as ARCH_HAS_PTE_SPECIAL and make it the proper
dependency so the real situation is clearer.
Link: http://lkml.kernel.org/r/87554aa78478a02a63f2c4cf60a847279ae3eb3b.1558547956.git.robin.murphy@arm.com
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Presently the remove_memory() interface is inherently broken. It tries
to remove memory but panics if some memory is not offline. The problem
is that it is impossible to ensure that all memory blocks are offline as
this function also takes lock_device_hotplug that is required to change
memory state via sysfs.
So, between calling this function and offlining all memory blocks there
is always a window when lock_device_hotplug is released, and therefore,
there is always a chance for a panic during this window.
Make this interface to return an error if memory removal fails. This
way it is safe to call this function without panicking machine, and also
makes it symmetric to add_memory() which already returns an error.
Link: http://lkml.kernel.org/r/20190517215438.6487-3-pasha.tatashin@soleen.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Ross Zwisler <zwisler@kernel.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We can't expose UAPI symbols differently based on CONFIG_ symbols, as
userspace won't have them available. Instead always define the flag,
but only respect it based on the config option.
Link: http://lkml.kernel.org/r/20190703122359.18200-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The description of cma_declare_contiguous() indicates that if the
'fixed' argument is true the reserved contiguous area must be exactly at
the address of the 'base' argument.
However, the function currently allows the 'base', 'size', and 'limit'
arguments to be silently adjusted to meet alignment constraints. This
commit enforces the documented behavior through explicit checks that
return an error if the region does not fit within a specified region.
Link: http://lkml.kernel.org/r/1561422051-16142-1-git-send-email-opendmb@gmail.com
Fixes: 5ea3b1b2f8 ("cma: add placement specifier for "cma=" kernel parameter")
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Cc: Yue Hu <huyue2@yulong.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Peng Fan <peng.fan@nxp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
z3fold_page_migration() calls memcpy(new_zhdr, zhdr, PAGE_SIZE).
However, zhdr contains fields that can't be directly coppied over (ex:
list_head, a circular linked list). We only need to initialize the
linked lists in new_zhdr, as z3fold_isolate_page() already ensures that
these lists are empty
Additionally it is possible that zhdr->work has been placed in a
workqueue. In this case we shouldn't migrate the page, as zhdr->work
references zhdr as opposed to new_zhdr.
Link: http://lkml.kernel.org/r/20190716000520.230595-1-henryburns@google.com
Fixes: 1f862989b0 ("mm/z3fold.c: support page migration")
Signed-off-by: Henry Burns <henryburns@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Vitaly Vul <vitaly.vul@sony.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Jonathan Adams <jwadams@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
z3fold_page_migrate() will never succeed because it attempts to acquire
a lock that has already been taken by migrate.c in __unmap_and_move().
__unmap_and_move() migrate.c
trylock_page(oldpage)
move_to_new_page(oldpage_newpage)
a_ops->migrate_page(oldpage, newpage)
z3fold_page_migrate(oldpage, newpage)
trylock_page(oldpage)
Link: http://lkml.kernel.org/r/20190710213238.91835-1-henryburns@google.com
Fixes: 1f862989b0 ("mm/z3fold.c: support page migration")
Signed-off-by: Henry Burns <henryburns@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Vitaly Vul <vitaly.vul@sony.com>
Cc: Jonathan Adams <jwadams@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Snild Dolkow <snild@sony.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Six sites are presently altering current->reclaim_state. There is a
risk that one function stomps on a caller's value. Use a helper
function to catch such errors.
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are six different reclaim paths by now:
- kswapd reclaim path
- node reclaim path
- hibernate preallocate memory reclaim path
- direct reclaim path
- memcg reclaim path
- memcg softlimit reclaim path
The slab caches reclaimed in these paths are only calculated in the
above three paths.
There're some drawbacks if we don't calculate the reclaimed slab caches.
- The sc->nr_reclaimed isn't correct if there're some slab caches
relcaimed in this path.
- The slab caches may be reclaimed thoroughly if there're lots of
reclaimable slab caches and few page caches.
Let's take an easy example for this case. If one memcg is full of
slab caches and the limit of it is 512M, in other words there're
approximately 512M slab caches in this memcg. Then the limit of the
memcg is reached and the memcg reclaim begins, and then in this memcg
reclaim path it will continuesly reclaim the slab caches until the
sc->priority drops to 0. After this reclaim stops, you will find
there're few slab caches left, which is less than 20M in my test
case. While after this patch applied the number is greater than 300M
and the sc->priority only drops to 3.
Link: http://lkml.kernel.org/r/1561112086-6169-3-git-send-email-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/vmscan: calculate reclaimed slab in all reclaim paths".
This patchset is to fix the issues in doing shrink slab.
There're six different reclaim paths by now,
- kswapd reclaim path
- node reclaim path
- hibernate preallocate memory reclaim path
- direct reclaim path
- memcg reclaim path
- memcg softlimit reclaim path
The slab caches reclaimed in these paths are only calculated in the
above three paths. The issues are detailed explained in patch #2. We
should calculate the reclaimed slab caches in every reclaim path. In
order to do it, the struct reclaim_state is placed into the struct
shrink_control.
In node reclaim path, there'is another issue about shrinking slab, which
is adressed in "mm/vmscan: shrink slab in node reclaim"
(https://lore.kernel.org/linux-mm/1559874946-22960-1-git-send-email-laoar.shao@gmail.com/).
This patch (of 2):
The struct reclaim_state is used to record how many slab caches are
reclaimed in one reclaim path. The struct shrink_control is used to
control one reclaim path. So we'd better put reclaim_state into
shrink_control.
[laoar.shao@gmail.com: remove reclaim_state assignment from __perform_reclaim()]
Link: http://lkml.kernel.org/r/1561381582-13697-1-git-send-email-laoar.shao@gmail.com
Link: http://lkml.kernel.org/r/1561112086-6169-2-git-send-email-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After commit 815744d751 ("mm: memcontrol: don't batch updates of local
VM stats and events"), the local VM counter are not in sync with the
hierarchical ones.
Below is one example in a leaf memcg on my server (with 8 CPUs):
inactive_file 3567570944
total_inactive_file 3568029696
We find that the deviation is very great because the 'val' in
__mod_memcg_state() is in pages while the effective value in
memcg_stat_show() is in bytes.
So the maximum of this deviation between local VM stats and total VM
stats can be (32 * number_of_cpu * PAGE_SIZE), that may be an
unacceptably great value.
We should keep the local VM stats in sync with the total stats. In
order to keep this behavior the same across counters, this patch updates
__mod_lruvec_state() and __count_memcg_events() as well.
Link: http://lkml.kernel.org/r/1562851979-10610-1-git-send-email-laoar.shao@gmail.com
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yafang Shao <shaoyafang@didiglobal.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
One of the gfp flags used to show that a page is movable is
__GFP_HIGHMEM. Currently z3fold_alloc() fails when __GFP_HIGHMEM is
passed. Now that z3fold pages are movable, we allow __GFP_HIGHMEM. We
strip the movability related flags from the call to kmem_cache_alloc()
for our slots since it is a kernel allocation.
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/20190712222118.108192-1-henryburns@google.com
Signed-off-by: Henry Burns <henryburns@google.com>
Acked-by: Vitaly Wool <vitalywool@gmail.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A comment referred to a non-existent function alloc_cma(), which should
have been cma_alloc().
Link: http://lkml.kernel.org/r/20190712085549.5920-1-ryh.szk.cmnty@gmail.com
Signed-off-by: Ryohei Suzuki <ryh.szk.cmnty@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Clang gets rather confused about two variables in the same special
section when one of them is not initialized, leading to an assembler
warning later:
/tmp/slab_common-18f869.s: Assembler messages:
/tmp/slab_common-18f869.s:7526: Warning: ignoring changed section attributes for .data..ro_after_init
Adding an initialization to kmalloc_caches is rather silly here
but does avoid the issue.
Link: https://bugs.llvm.org/show_bug.cgi?id=42570
Link: http://lkml.kernel.org/r/20190712090455.266021-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Roman Gushchin <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When CONFIG_SYSFS is disabled but CONFIG_TMPFS is enabled, we get a
warning about shmem_parse_huge() never being called:
mm/shmem.c:417:12: error: unused function 'shmem_parse_huge' [-Werror,-Wunused-function]
static int shmem_parse_huge(const char *str)
Change the #ifdef so we no longer build this function in that configuration.
Link: http://lkml.kernel.org/r/20190712091141.673355-1-arnd@arndb.de
Fixes: 144df3b288c4 ("vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Vineeth Remanan Pillai <vpillai@digitalocean.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As reported by Henry Burns:
Running z3fold stress testing with address sanitization showed zhdr->slots
was being used after it was freed.
z3fold_free(z3fold_pool, handle)
free_handle(handle)
kmem_cache_free(pool->c_handle, zhdr->slots)
release_z3fold_page_locked_list(kref)
__release_z3fold_page(zhdr, true)
zhdr_to_pool(zhdr)
slots_to_pool(zhdr->slots) *BOOM*
To fix this, add pointer to the pool back to z3fold_header and modify
zhdr_to_pool to return zhdr->pool.
Link: http://lkml.kernel.org/r/20190708134808.e89f3bfadd9f6ffd7eff9ba9@gmail.com
Fixes: 7c2b8baa61 ("mm/z3fold.c: add structure for buddy handles")
Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Reported-by: Henry Burns <henryburns@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Jonathan Adams <jwadams@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The stuff under sysctl describes /sys interface from userspace
point of view. So, add it to the admin-guide and remove the
:orphan: from its index file.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Rename the /proc/sys/ documentation files to ReST, using the
README file as a template for an index.rst, adding the other
files there via TOC markup.
Despite being written on different times with different
styles, try to make them somewhat coherent with a similar
look and feel, ensuring that they'll look nice as both
raw text file and as via the html output produced by the
Sphinx build system.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Improvements and bug fixes for the hmm interface in the kernel:
- Improve clarity, locking and APIs related to the 'hmm mirror' feature
merged last cycle. In linux-next we now see AMDGPU and nouveau to be
using this API.
- Remove old or transitional hmm APIs. These are hold overs from the past
with no users, or APIs that existed only to manage cross tree conflicts.
There are still a few more of these cleanups that didn't make the merge
window cut off.
- Improve some core mm APIs:
* export alloc_pages_vma() for driver use
* refactor into devm_request_free_mem_region() to manage
DEVICE_PRIVATE resource reservations
* refactor duplicative driver code into the core dev_pagemap
struct
- Remove hmm wrappers of improved core mm APIs, instead have drivers use
the simplified API directly
- Remove DEVICE_PUBLIC
- Simplify the kconfig flow for the hmm users and core code
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Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
Pull HMM updates from Jason Gunthorpe:
"Improvements and bug fixes for the hmm interface in the kernel:
- Improve clarity, locking and APIs related to the 'hmm mirror'
feature merged last cycle. In linux-next we now see AMDGPU and
nouveau to be using this API.
- Remove old or transitional hmm APIs. These are hold overs from the
past with no users, or APIs that existed only to manage cross tree
conflicts. There are still a few more of these cleanups that didn't
make the merge window cut off.
- Improve some core mm APIs:
- export alloc_pages_vma() for driver use
- refactor into devm_request_free_mem_region() to manage
DEVICE_PRIVATE resource reservations
- refactor duplicative driver code into the core dev_pagemap
struct
- Remove hmm wrappers of improved core mm APIs, instead have drivers
use the simplified API directly
- Remove DEVICE_PUBLIC
- Simplify the kconfig flow for the hmm users and core code"
* tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (42 commits)
mm: don't select MIGRATE_VMA_HELPER from HMM_MIRROR
mm: remove the HMM config option
mm: sort out the DEVICE_PRIVATE Kconfig mess
mm: simplify ZONE_DEVICE page private data
mm: remove hmm_devmem_add
mm: remove hmm_vma_alloc_locked_page
nouveau: use devm_memremap_pages directly
nouveau: use alloc_page_vma directly
PCI/P2PDMA: use the dev_pagemap internal refcount
device-dax: use the dev_pagemap internal refcount
memremap: provide an optional internal refcount in struct dev_pagemap
memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag
memremap: remove the data field in struct dev_pagemap
memremap: add a migrate_to_ram method to struct dev_pagemap_ops
memremap: lift the devmap_enable manipulation into devm_memremap_pages
memremap: pass a struct dev_pagemap to ->kill and ->cleanup
memremap: move dev_pagemap callbacks into a separate structure
memremap: validate the pagemap type passed to devm_memremap_pages
mm: factor out a devm_request_free_mem_region helper
mm: export alloc_pages_vma
...
Here is the "big" driver core and debugfs changes for 5.3-rc1
It's a lot of different patches, all across the tree due to some api
changes and lots of debugfs cleanups. Because of this, there is going
to be some merge issues with your tree at the moment, I'll follow up
with the expected resolutions to make it easier for you.
Other than the debugfs cleanups, in this set of changes we have:
- bus iteration function cleanups (will cause build warnings
with s390 and coresight drivers in your tree)
- scripts/get_abi.pl tool to display and parse Documentation/ABI
entries in a simple way
- cleanups to Documenatation/ABI/ entries to make them parse
easier due to typos and other minor things
- default_attrs use for some ktype users
- driver model documentation file conversions to .rst
- compressed firmware file loading
- deferred probe fixes
All of these have been in linux-next for a while, with a bunch of merge
issues that Stephen has been patient with me for. Other than the merge
issues, functionality is working properly in linux-next :)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core and debugfs updates from Greg KH:
"Here is the "big" driver core and debugfs changes for 5.3-rc1
It's a lot of different patches, all across the tree due to some api
changes and lots of debugfs cleanups.
Other than the debugfs cleanups, in this set of changes we have:
- bus iteration function cleanups
- scripts/get_abi.pl tool to display and parse Documentation/ABI
entries in a simple way
- cleanups to Documenatation/ABI/ entries to make them parse easier
due to typos and other minor things
- default_attrs use for some ktype users
- driver model documentation file conversions to .rst
- compressed firmware file loading
- deferred probe fixes
All of these have been in linux-next for a while, with a bunch of
merge issues that Stephen has been patient with me for"
* tag 'driver-core-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (102 commits)
debugfs: make error message a bit more verbose
orangefs: fix build warning from debugfs cleanup patch
ubifs: fix build warning after debugfs cleanup patch
driver: core: Allow subsystems to continue deferring probe
drivers: base: cacheinfo: Ensure cpu hotplug work is done before Intel RDT
arch_topology: Remove error messages on out-of-memory conditions
lib: notifier-error-inject: no need to check return value of debugfs_create functions
swiotlb: no need to check return value of debugfs_create functions
ceph: no need to check return value of debugfs_create functions
sunrpc: no need to check return value of debugfs_create functions
ubifs: no need to check return value of debugfs_create functions
orangefs: no need to check return value of debugfs_create functions
nfsd: no need to check return value of debugfs_create functions
lib: 842: no need to check return value of debugfs_create functions
debugfs: provide pr_fmt() macro
debugfs: log errors when something goes wrong
drivers: s390/cio: Fix compilation warning about const qualifiers
drivers: Add generic helper to match by of_node
driver_find_device: Unify the match function with class_find_device()
bus_find_device: Unify the match callback with class_find_device
...
Merge updates from Andrew Morton:
"Am experimenting with splitting MM up into identifiable subsystems
perhaps with a view to gitifying it in complex ways. Also with more
verbose "incoming" emails.
Most of MM is here and a few other trees.
Subsystems affected by this patch series:
- hotfixes
- iommu
- scripts
- arch/sh
- ocfs2
- mm:slab-generic
- mm:slub
- mm:kmemleak
- mm:kasan
- mm:cleanups
- mm:debug
- mm:pagecache
- mm:swap
- mm:memcg
- mm:gup
- mm:pagemap
- mm:infrastructure
- mm:vmalloc
- mm:initialization
- mm:pagealloc
- mm:vmscan
- mm:tools
- mm:proc
- mm:ras
- mm:oom-kill
hotfixes:
mm: vmscan: scan anonymous pages on file refaults
mm/nvdimm: add is_ioremap_addr and use that to check ioremap address
mm/memcontrol: fix wrong statistics in memory.stat
mm/z3fold.c: lock z3fold page before __SetPageMovable()
nilfs2: do not use unexported cpu_to_le32()/le32_to_cpu() in uapi header
MAINTAINERS: nilfs2: update email address
iommu:
include/linux/dmar.h: replace single-char identifiers in macros
scripts:
scripts/decode_stacktrace: match basepath using shell prefix operator, not regex
scripts/decode_stacktrace: look for modules with .ko.debug extension
scripts/spelling.txt: drop "sepc" from the misspelling list
scripts/spelling.txt: add spelling fix for prohibited
scripts/decode_stacktrace: Accept dash/underscore in modules
scripts/spelling.txt: add more spellings to spelling.txt
arch/sh:
arch/sh/configs/sdk7786_defconfig: remove CONFIG_LOGFS
sh: config: remove left-over BACKLIGHT_LCD_SUPPORT
sh: prevent warnings when using iounmap
ocfs2:
fs: ocfs: fix spelling mistake "hearbeating" -> "heartbeat"
ocfs2/dlm: use struct_size() helper
ocfs2: add last unlock times in locking_state
ocfs2: add locking filter debugfs file
ocfs2: add first lock wait time in locking_state
ocfs: no need to check return value of debugfs_create functions
fs/ocfs2/dlmglue.c: unneeded variable: "status"
ocfs2: use kmemdup rather than duplicating its implementation
mm:slab-generic:
Patch series "mm/slab: Improved sanity checking":
mm/slab: validate cache membership under freelist hardening
mm/slab: sanity-check page type when looking up cache
lkdtm/heap: add tests for freelist hardening
mm:slub:
mm/slub.c: avoid double string traverse in kmem_cache_flags()
slub: don't panic for memcg kmem cache creation failure
mm:kmemleak:
mm/kmemleak.c: fix check for softirq context
mm/kmemleak.c: change error at _write when kmemleak is disabled
docs: kmemleak: add more documentation details
mm:kasan:
mm/kasan: print frame description for stack bugs
Patch series "Bitops instrumentation for KASAN", v5:
lib/test_kasan: add bitops tests
x86: use static_cpu_has in uaccess region to avoid instrumentation
asm-generic, x86: add bitops instrumentation for KASAN
Patch series "mm/kasan: Add object validation in ksize()", v3:
mm/kasan: introduce __kasan_check_{read,write}
mm/kasan: change kasan_check_{read,write} to return boolean
lib/test_kasan: Add test for double-kzfree detection
mm/slab: refactor common ksize KASAN logic into slab_common.c
mm/kasan: add object validation in ksize()
mm:cleanups:
include/linux/pfn_t.h: remove pfn_t_to_virt()
Patch series "remove ARCH_SELECT_MEMORY_MODEL where it has no effect":
arm: remove ARCH_SELECT_MEMORY_MODEL
s390: remove ARCH_SELECT_MEMORY_MODEL
sparc: remove ARCH_SELECT_MEMORY_MODEL
mm/gup.c: make follow_page_mask() static
mm/memory.c: trivial clean up in insert_page()
mm: make !CONFIG_HUGE_PAGE wrappers into static inlines
include/linux/mm_types.h: ifdef struct vm_area_struct::swap_readahead_info
mm: remove the account_page_dirtied export
mm/page_isolation.c: change the prototype of undo_isolate_page_range()
include/linux/vmpressure.h: use spinlock_t instead of struct spinlock
mm: remove the exporting of totalram_pages
include/linux/pagemap.h: document trylock_page() return value
mm:debug:
mm/failslab.c: by default, do not fail allocations with direct reclaim only
Patch series "debug_pagealloc improvements":
mm, debug_pagelloc: use static keys to enable debugging
mm, page_alloc: more extensive free page checking with debug_pagealloc
mm, debug_pagealloc: use a page type instead of page_ext flag
mm:pagecache:
Patch series "fix filler_t callback type mismatches", v2:
mm/filemap.c: fix an overly long line in read_cache_page
mm/filemap: don't cast ->readpage to filler_t for do_read_cache_page
jffs2: pass the correct prototype to read_cache_page
9p: pass the correct prototype to read_cache_page
mm/filemap.c: correct the comment about VM_FAULT_RETRY
mm:swap:
mm, swap: fix race between swapoff and some swap operations
mm/swap_state.c: simplify total_swapcache_pages() with get_swap_device()
mm, swap: use rbtree for swap_extent
mm/mincore.c: fix race between swapoff and mincore
mm:memcg:
memcg, oom: no oom-kill for __GFP_RETRY_MAYFAIL
memcg, fsnotify: no oom-kill for remote memcg charging
mm, memcg: introduce memory.events.local
mm: memcontrol: dump memory.stat during cgroup OOM
Patch series "mm: reparent slab memory on cgroup removal", v7:
mm: memcg/slab: postpone kmem_cache memcg pointer initialization to memcg_link_cache()
mm: memcg/slab: rename slab delayed deactivation functions and fields
mm: memcg/slab: generalize postponed non-root kmem_cache deactivation
mm: memcg/slab: introduce __memcg_kmem_uncharge_memcg()
mm: memcg/slab: unify SLAB and SLUB page accounting
mm: memcg/slab: don't check the dying flag on kmem_cache creation
mm: memcg/slab: synchronize access to kmem_cache dying flag using a spinlock
mm: memcg/slab: rework non-root kmem_cache lifecycle management
mm: memcg/slab: stop setting page->mem_cgroup pointer for slab pages
mm: memcg/slab: reparent memcg kmem_caches on cgroup removal
mm, memcg: add a memcg_slabinfo debugfs file
mm:gup:
Patch series "switch the remaining architectures to use generic GUP", v4:
mm: use untagged_addr() for get_user_pages_fast addresses
mm: simplify gup_fast_permitted
mm: lift the x86_32 PAE version of gup_get_pte to common code
MIPS: use the generic get_user_pages_fast code
sh: add the missing pud_page definition
sh: use the generic get_user_pages_fast code
sparc64: add the missing pgd_page definition
sparc64: define untagged_addr()
sparc64: use the generic get_user_pages_fast code
mm: rename CONFIG_HAVE_GENERIC_GUP to CONFIG_HAVE_FAST_GUP
mm: reorder code blocks in gup.c
mm: consolidate the get_user_pages* implementations
mm: validate get_user_pages_fast flags
mm: move the powerpc hugepd code to mm/gup.c
mm: switch gup_hugepte to use try_get_compound_head
mm: mark the page referenced in gup_hugepte
mm/gup: speed up check_and_migrate_cma_pages() on huge page
mm/gup.c: remove some BUG_ONs from get_gate_page()
mm/gup.c: mark undo_dev_pagemap as __maybe_unused
mm:pagemap:
asm-generic, x86: introduce generic pte_{alloc,free}_one[_kernel]
alpha: switch to generic version of pte allocation
arm: switch to generic version of pte allocation
arm64: switch to generic version of pte allocation
csky: switch to generic version of pte allocation
m68k: sun3: switch to generic version of pte allocation
mips: switch to generic version of pte allocation
nds32: switch to generic version of pte allocation
nios2: switch to generic version of pte allocation
parisc: switch to generic version of pte allocation
riscv: switch to generic version of pte allocation
um: switch to generic version of pte allocation
unicore32: switch to generic version of pte allocation
mm/pgtable: drop pgtable_t variable from pte_fn_t functions
mm/memory.c: fail when offset == num in first check of __vm_map_pages()
mm:infrastructure:
mm/mmu_notifier: use hlist_add_head_rcu()
mm:vmalloc:
Patch series "Some cleanups for the KVA/vmalloc", v5:
mm/vmalloc.c: remove "node" argument
mm/vmalloc.c: preload a CPU with one object for split purpose
mm/vmalloc.c: get rid of one single unlink_va() when merge
mm/vmalloc.c: switch to WARN_ON() and move it under unlink_va()
mm/vmalloc.c: spelling> s/informaion/information/
mm:initialization:
mm/large system hash: use vmalloc for size > MAX_ORDER when !hashdist
mm/large system hash: clear hashdist when only one node with memory is booted
mm:pagealloc:
arm64: move jump_label_init() before parse_early_param()
Patch series "add init_on_alloc/init_on_free boot options", v10:
mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options
mm: init: report memory auto-initialization features at boot time
mm:vmscan:
mm: vmscan: remove double slab pressure by inc'ing sc->nr_scanned
mm: vmscan: correct some vmscan counters for THP swapout
mm:tools:
tools/vm/slabinfo: order command line options
tools/vm/slabinfo: add partial slab listing to -X
tools/vm/slabinfo: add option to sort by partial slabs
tools/vm/slabinfo: add sorting info to help menu
mm:proc:
proc: use down_read_killable mmap_sem for /proc/pid/maps
proc: use down_read_killable mmap_sem for /proc/pid/smaps_rollup
proc: use down_read_killable mmap_sem for /proc/pid/pagemap
proc: use down_read_killable mmap_sem for /proc/pid/clear_refs
proc: use down_read_killable mmap_sem for /proc/pid/map_files
mm: use down_read_killable for locking mmap_sem in access_remote_vm
mm: smaps: split PSS into components
mm: vmalloc: show number of vmalloc pages in /proc/meminfo
mm:ras:
mm/memory-failure.c: clarify error message
mm:oom-kill:
mm: memcontrol: use CSS_TASK_ITER_PROCS at mem_cgroup_scan_tasks()
mm, oom: refactor dump_tasks for memcg OOMs
mm, oom: remove redundant task_in_mem_cgroup() check
oom: decouple mems_allowed from oom_unkillable_task
mm/oom_kill.c: remove redundant OOM score normalization in select_bad_process()"
* akpm: (147 commits)
mm/oom_kill.c: remove redundant OOM score normalization in select_bad_process()
oom: decouple mems_allowed from oom_unkillable_task
mm, oom: remove redundant task_in_mem_cgroup() check
mm, oom: refactor dump_tasks for memcg OOMs
mm: memcontrol: use CSS_TASK_ITER_PROCS at mem_cgroup_scan_tasks()
mm/memory-failure.c: clarify error message
mm: vmalloc: show number of vmalloc pages in /proc/meminfo
mm: smaps: split PSS into components
mm: use down_read_killable for locking mmap_sem in access_remote_vm
proc: use down_read_killable mmap_sem for /proc/pid/map_files
proc: use down_read_killable mmap_sem for /proc/pid/clear_refs
proc: use down_read_killable mmap_sem for /proc/pid/pagemap
proc: use down_read_killable mmap_sem for /proc/pid/smaps_rollup
proc: use down_read_killable mmap_sem for /proc/pid/maps
tools/vm/slabinfo: add sorting info to help menu
tools/vm/slabinfo: add option to sort by partial slabs
tools/vm/slabinfo: add partial slab listing to -X
tools/vm/slabinfo: order command line options
mm: vmscan: correct some vmscan counters for THP swapout
mm: vmscan: remove double slab pressure by inc'ing sc->nr_scanned
...
Since commit bbbe480297 ("mm, oom: remove 'prefer children over
parent' heuristic") removed the
"%s: Kill process %d (%s) score %u or sacrifice child\n"
line, oc->chosen_points is no longer used after select_bad_process().
Link: http://lkml.kernel.org/r/1560853435-15575-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
oom_unkillable_task() can be called from three different contexts i.e.
global OOM, memcg OOM and oom_score procfs interface. At the moment
oom_unkillable_task() does a task_in_mem_cgroup() check on the given
process. Since there is no reason to perform task_in_mem_cgroup()
check for global OOM and oom_score procfs interface, those contexts
provide NULL memcg and skips the task_in_mem_cgroup() check. However
for memcg OOM context, the oom_unkillable_task() is always called from
mem_cgroup_scan_tasks() and thus task_in_mem_cgroup() check becomes
redundant and effectively dead code. So, just remove the
task_in_mem_cgroup() check altogether.
Link: http://lkml.kernel.org/r/20190624212631.87212-2-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Jackson <pj@sgi.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
dump_tasks() traverses all the existing processes even for the memcg OOM
context which is not only unnecessary but also wasteful. This imposes a
long RCU critical section even from a contained context which can be quite
disruptive.
Change dump_tasks() to be aligned with select_bad_process and use
mem_cgroup_scan_tasks to selectively traverse only processes of the target
memcg hierarchy during memcg OOM.
Link: http://lkml.kernel.org/r/20190617231207.160865-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since commit c03cd7738a ("cgroup: Include dying leaders with live
threads in PROCS iterations") corrected how CSS_TASK_ITER_PROCS works,
mem_cgroup_scan_tasks() can use CSS_TASK_ITER_PROCS in order to check
only one thread from each thread group.
[penguin-kernel@I-love.SAKURA.ne.jp: remove thread group leader check in oom_evaluate_task()]
Link: http://lkml.kernel.org/r/1560853257-14934-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Link: http://lkml.kernel.org/r/c763afc8-f0ae-756a-56a7-395f625b95fc@i-love.sakura.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some user who install SIGBUS handler that does longjmp out therefore
keeping the process alive is confused by the error message
"[188988.765862] Memory failure: 0x1840200: Killing cellsrv:33395 due to hardware memory corruption"
Slightly modify the error message to improve clarity.
Link: http://lkml.kernel.org/r/1558403523-22079-1-git-send-email-jane.chu@oracle.com
Signed-off-by: Jane Chu <jane.chu@oracle.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Pankaj Gupta <pagupta@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Vmalloc() is getting more and more used these days (kernel stacks, bpf and
percpu allocator are new top users), and the total % of memory consumed by
vmalloc() can be pretty significant and changes dynamically.
/proc/meminfo is the best place to display this information: its top goal
is to show top consumers of the memory.
Since the VmallocUsed field in /proc/meminfo is not in use for quite a
long time (it has been defined to 0 by a5ad88ce8c ("mm: get rid of
'vmalloc_info' from /proc/meminfo")), let's reuse it for showing the
actual physical memory consumption of vmalloc().
Link: http://lkml.kernel.org/r/20190417194002.12369-3-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This function is used by ptrace and proc files like /proc/pid/cmdline and
/proc/pid/environ.
Access_remote_vm never returns error codes, all errors are ignored and
only size of successfully read data is returned. So, if current task was
killed we'll simply return 0 (bytes read).
Mmap_sem could be locked for a long time or forever if something goes
wrong. Using a killable lock permits cleanup of stuck tasks and
simplifies investigation.
Link: http://lkml.kernel.org/r/156007494202.3335.16782303099589302087.stgit@buzz
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit bd4c82c22c ("mm, THP, swap: delay splitting THP after swapped
out"), THP can be swapped out in a whole. But, nr_reclaimed and some
other vm counters still get inc'ed by one even though a whole THP (512
pages) gets swapped out.
This doesn't make too much sense to memory reclaim.
For example, direct reclaim may just need reclaim SWAP_CLUSTER_MAX
pages, reclaiming one THP could fulfill it. But, if nr_reclaimed is not
increased correctly, direct reclaim may just waste time to reclaim more
pages, SWAP_CLUSTER_MAX * 512 pages in worst case.
And, it may cause pgsteal_{kswapd|direct} is greater than
pgscan_{kswapd|direct}, like the below:
pgsteal_kswapd 122933
pgsteal_direct 26600225
pgscan_kswapd 174153
pgscan_direct 14678312
nr_reclaimed and nr_scanned must be fixed in parallel otherwise it would
break some page reclaim logic, e.g.
vmpressure: this looks at the scanned/reclaimed ratio so it won't change
semantics as long as scanned & reclaimed are fixed in parallel.
compaction/reclaim: compaction wants a certain number of physical pages
freed up before going back to compacting.
kswapd priority raising: kswapd raises priority if we scan fewer pages
than the reclaim target (which itself is obviously expressed in order-0
pages). As a result, kswapd can falsely raise its aggressiveness even
when it's making great progress.
Other than nr_scanned and nr_reclaimed, some other counters, e.g.
pgactivate, nr_skipped, nr_ref_keep and nr_unmap_fail need to be fixed too
since they are user visible via cgroup, /proc/vmstat or trace points,
otherwise they would be underreported.
When isolating pages from LRUs, nr_taken has been accounted in base page,
but nr_scanned and nr_skipped are still accounted in THP. It doesn't make
too much sense too since this may cause trace point underreport the
numbers as well.
So accounting those counters in base page instead of accounting THP as one
page.
nr_dirty, nr_unqueued_dirty, nr_congested and nr_writeback are used by
file cache, so they are not impacted by THP swap.
This change may result in lower steal/scan ratio in some cases since THP
may get split during page reclaim, then a part of tail pages get reclaimed
instead of the whole 512 pages, but nr_scanned is accounted by 512,
particularly for direct reclaim. But, this should be not a significant
issue.
Link: http://lkml.kernel.org/r/1559025859-72759-2-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 9092c71bb7 ("mm: use sc->priority for slab shrink targets") has
broken up the relationship between sc->nr_scanned and slab pressure.
The sc->nr_scanned can't double slab pressure anymore. So, it sounds no
sense to still keep sc->nr_scanned inc'ed. Actually, it would prevent
from adding pressure on slab shrink since excessive sc->nr_scanned would
prevent from scan->priority raise.
The bonnie test doesn't show this would change the behavior of slab
shrinkers.
w/ w/o
/sec %CP /sec %CP
Sequential delete: 3960.6 94.6 3997.6 96.2
Random delete: 2518 63.8 2561.6 64.6
The slight increase of "/sec" without the patch would be caused by the
slight increase of CPU usage.
Link: http://lkml.kernel.org/r/1559025859-72759-1-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "add init_on_alloc/init_on_free boot options", v10.
Provide init_on_alloc and init_on_free boot options.
These are aimed at preventing possible information leaks and making the
control-flow bugs that depend on uninitialized values more deterministic.
Enabling either of the options guarantees that the memory returned by the
page allocator and SL[AU]B is initialized with zeroes. SLOB allocator
isn't supported at the moment, as its emulation of kmem caches complicates
handling of SLAB_TYPESAFE_BY_RCU caches correctly.
Enabling init_on_free also guarantees that pages and heap objects are
initialized right after they're freed, so it won't be possible to access
stale data by using a dangling pointer.
As suggested by Michal Hocko, right now we don't let the heap users to
disable initialization for certain allocations. There's not enough
evidence that doing so can speed up real-life cases, and introducing ways
to opt-out may result in things going out of control.
This patch (of 2):
The new options are needed to prevent possible information leaks and make
control-flow bugs that depend on uninitialized values more deterministic.
This is expected to be on-by-default on Android and Chrome OS. And it
gives the opportunity for anyone else to use it under distros too via the
boot args. (The init_on_free feature is regularly requested by folks
where memory forensics is included in their threat models.)
init_on_alloc=1 makes the kernel initialize newly allocated pages and heap
objects with zeroes. Initialization is done at allocation time at the
places where checks for __GFP_ZERO are performed.
init_on_free=1 makes the kernel initialize freed pages and heap objects
with zeroes upon their deletion. This helps to ensure sensitive data
doesn't leak via use-after-free accesses.
Both init_on_alloc=1 and init_on_free=1 guarantee that the allocator
returns zeroed memory. The two exceptions are slab caches with
constructors and SLAB_TYPESAFE_BY_RCU flag. Those are never
zero-initialized to preserve their semantics.
Both init_on_alloc and init_on_free default to zero, but those defaults
can be overridden with CONFIG_INIT_ON_ALLOC_DEFAULT_ON and
CONFIG_INIT_ON_FREE_DEFAULT_ON.
If either SLUB poisoning or page poisoning is enabled, those options take
precedence over init_on_alloc and init_on_free: initialization is only
applied to unpoisoned allocations.
Slowdown for the new features compared to init_on_free=0, init_on_alloc=0:
hackbench, init_on_free=1: +7.62% sys time (st.err 0.74%)
hackbench, init_on_alloc=1: +7.75% sys time (st.err 2.14%)
Linux build with -j12, init_on_free=1: +8.38% wall time (st.err 0.39%)
Linux build with -j12, init_on_free=1: +24.42% sys time (st.err 0.52%)
Linux build with -j12, init_on_alloc=1: -0.13% wall time (st.err 0.42%)
Linux build with -j12, init_on_alloc=1: +0.57% sys time (st.err 0.40%)
The slowdown for init_on_free=0, init_on_alloc=0 compared to the baseline
is within the standard error.
The new features are also going to pave the way for hardware memory
tagging (e.g. arm64's MTE), which will require both on_alloc and on_free
hooks to set the tags for heap objects. With MTE, tagging will have the
same cost as memory initialization.
Although init_on_free is rather costly, there are paranoid use-cases where
in-memory data lifetime is desired to be minimized. There are various
arguments for/against the realism of the associated threat models, but
given that we'll need the infrastructure for MTE anyway, and there are
people who want wipe-on-free behavior no matter what the performance cost,
it seems reasonable to include it in this series.
[glider@google.com: v8]
Link: http://lkml.kernel.org/r/20190626121943.131390-2-glider@google.com
[glider@google.com: v9]
Link: http://lkml.kernel.org/r/20190627130316.254309-2-glider@google.com
[glider@google.com: v10]
Link: http://lkml.kernel.org/r/20190628093131.199499-2-glider@google.com
Link: http://lkml.kernel.org/r/20190617151050.92663-2-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.cz> [page and dmapool parts
Acked-by: James Morris <jamorris@linux.microsoft.com>]
Cc: Christoph Lameter <cl@linux.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Kostya Serebryany <kcc@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Sandeep Patil <sspatil@android.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Jann Horn <jannh@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_NUMA on 64-bit CPUs currently enables hashdist unconditionally even
when booting on single node machines. This causes the large system hashes
to be allocated with vmalloc, and mapped with small pages.
This change clears hashdist if only one node has come up with memory.
This results in the important large inode and dentry hashes using memblock
allocations. All others are within 4MB size up to about 128GB of RAM,
which allows them to be allocated from the linear map on most non-NUMA
images.
Other big hashes like futex and TCP should eventually be moved over to the
same style of allocation as those vfs caches that use HASH_EARLY if
!hashdist, so they don't exceed MAX_ORDER on very large non-NUMA images.
This brings dTLB misses for linux kernel tree `git diff` from ~45,000 to
~8,000 on a Kaby Lake KVM guest with 8MB dentry hash and mitigations=off
(performance is in the noise, under 1% difference, page tables are likely
to be well cached for this workload).
Link: http://lkml.kernel.org/r/20190605144814.29319-2-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kernel currently clamps large system hashes to MAX_ORDER when hashdist
is not set, which is rather arbitrary.
vmalloc space is limited on 32-bit machines, but this shouldn't result in
much more used because of small physical memory limiting system hash
sizes.
Include "vmalloc" or "linear" in the kernel log message.
Link: http://lkml.kernel.org/r/20190605144814.29319-1-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Trigger a warning if an object that is about to be freed is detached. We
used to have a BUG_ON(), but even though it is considered as faulty
behaviour that is not a good reason to break a system.
Link: http://lkml.kernel.org/r/20190606120411.8298-5-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It does not make sense to try to "unlink" the node that is definitely not
linked with a list nor tree. On the first merge step VA just points to
the previously disconnected busy area.
On the second step, check if the node has been merged and do "unlink" if
so, because now it points to an object that must be linked.
Link: http://lkml.kernel.org/r/20190606120411.8298-4-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Hillf Danton <hdanton@sina.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make mmu_notifier_register() safer by issuing a memory barrier before
registering a new notifier. This fixes a theoretical bug on weakly
ordered CPUs. For example, take this simplified use of notifiers by a
driver:
my_struct->mn.ops = &my_ops; /* (1) */
mmu_notifier_register(&my_struct->mn, mm)
...
hlist_add_head(&mn->hlist, &mm->mmu_notifiers); /* (2) */
...
Once mmu_notifier_register() releases the mm locks, another thread can
invalidate a range:
mmu_notifier_invalidate_range()
...
hlist_for_each_entry_rcu(mn, &mm->mmu_notifiers, hlist) {
if (mn->ops->invalidate_range)
The read side relies on the data dependency between mn and ops to ensure
that the pointer is properly initialized. But the write side doesn't have
any dependency between (1) and (2), so they could be reordered and the
readers could dereference an invalid mn->ops. mmu_notifier_register()
does take all the mm locks before adding to the hlist, but those have
acquire semantics which isn't sufficient.
By calling hlist_add_head_rcu() instead of hlist_add_head() we update the
hlist using a store-release, ensuring that readers see prior
initialization of my_struct. This situation is better illustated by
litmus test MP+onceassign+derefonce.
Link: http://lkml.kernel.org/r/20190502133532.24981-1-jean-philippe.brucker@arm.com
Fixes: cddb8a5c14 ("mmu-notifiers: core")
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the caller asks us for offset == num, we should already fail in the
first check, i.e. the one testing for offsets beyond the object.
At the moment, we are failing on the second test anyway, since count
cannot be 0. Still, to agree with the comment of the first test, we
should first test it there.
Link: http://lkml.kernel.org/r/20190528193004.GA7744@gmail.com
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Drop the pgtable_t variable from all implementation for pte_fn_t as none
of them use it. apply_to_pte_range() should stop computing it as well.
Should help us save some cycles.
Link: http://lkml.kernel.org/r/1556803126-26596-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Matthew Wilcox <willy@infradead.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <jglisse@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Several mips builds generate the following build warning.
mm/gup.c:1788:13: warning: 'undo_dev_pagemap' defined but not used
The function is declared unconditionally but only called from behind
various ifdefs. Mark it __maybe_unused.
Link: http://lkml.kernel.org/r/1562072523-22311-1-git-send-email-linux@roeck-us.net
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we end up without a PGD or PUD entry backing the gate area, don't BUG
-- just fail gracefully.
It's not entirely implausible that this could happen some day on x86. It
doesn't right now even with an execute-only emulated vsyscall page because
the fixmap shares the PUD, but the core mm code shouldn't rely on that
particular detail to avoid OOPSing.
Link: http://lkml.kernel.org/r/a1d9f4efb75b9d464e59fd6af00104b21c58f6f7.1561610798.git.luto@kernel.org
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Both hugetlb and thp locate on the same migration type of pageblock, since
they are allocated from a free_list[]. Based on this fact, it is enough
to check on a single subpage to decide the migration type of the whole
huge page. By this way, it saves (2M/4K - 1) times loop for pmd_huge on
x86, similar on other archs.
Furthermore, when executing isolate_huge_page(), it avoid taking global
hugetlb_lock many times, and meanless remove/add to the local link list
cma_page_list.
[akpm@linux-foundation.org: make `i' and `step' unsigned]
Link: http://lkml.kernel.org/r/1561612545-28997-1-git-send-email-kernelfans@gmail.com
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Keith Busch <keith.busch@intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All other get_user_page_fast cases mark the page referenced, so do this
here as well.
Link: http://lkml.kernel.org/r/20190625143715.1689-17-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This applies the overflow fixes from 8fde12ca79 ("mm: prevent
get_user_pages() from overflowing page refcount") to the powerpc hugepd
code and brings it back in sync with the other GUP cases.
Link: http://lkml.kernel.org/r/20190625143715.1689-16-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While only powerpc supports the hugepd case, the code is pretty generic
and I'd like to keep all GUP internals in one place.
Link: http://lkml.kernel.org/r/20190625143715.1689-15-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We can only deal with FOLL_WRITE and/or FOLL_LONGTERM in
get_user_pages_fast, so reject all other flags.
Link: http://lkml.kernel.org/r/20190625143715.1689-14-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Always build mm/gup.c so that we don't have to provide separate nommu
stubs. Also merge the get_user_pages_fast and __get_user_pages_fast stubs
when HAVE_FAST_GUP into the main implementations, which will never call
the fast path if HAVE_FAST_GUP is not set.
This also ensures the new put_user_pages* helpers are available for nommu,
as those are currently missing, which would create a problem as soon as we
actually grew users for it.
Link: http://lkml.kernel.org/r/20190625143715.1689-13-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This moves the actually exported functions towards the end of the file,
and reorders some functions to be in more logical blocks as a preparation
for moving various stubs inline into the main functionality using
IS_ENABLED().
Link: http://lkml.kernel.org/r/20190625143715.1689-12-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We only support the generic GUP now, so rename the config option to
be more clear, and always use the mm/Kconfig definition of the
symbol and select it from the arch Kconfigs.
Link: http://lkml.kernel.org/r/20190625143715.1689-11-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: James Hogan <jhogan@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The split low/high access is the only non-READ_ONCE version of gup_get_pte
that did show up in the various arch implemenations. Lift it to common
code and drop the ifdef based arch override.
Link: http://lkml.kernel.org/r/20190625143715.1689-4-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: James Hogan <jhogan@kernel.org>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pass in the already calculated end value instead of recomputing it, and
leave the end > start check in the callers instead of duplicating them in
the arch code.
Link: http://lkml.kernel.org/r/20190625143715.1689-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: James Hogan <jhogan@kernel.org>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "switch the remaining architectures to use generic GUP", v4.
A series to switch mips, sh and sparc64 to use the generic GUP code so
that we only have one codebase to touch for further improvements to this
code.
This patch (of 16):
This will allow sparc64, or any future architecture with memory tagging to
override its tags for get_user_pages and get_user_pages_fast.
Link: http://lkml.kernel.org/r/20190625143715.1689-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: David Miller <davem@davemloft.net>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are concerns about memory leaks from extensive use of memory cgroups
as each memory cgroup creates its own set of kmem caches. There is a
possiblity that the memcg kmem caches may remain even after the memory
cgroups have been offlined. Therefore, it will be useful to show the
status of each of memcg kmem caches.
This patch introduces a new <debugfs>/memcg_slabinfo file which is
somewhat similar to /proc/slabinfo in format, but lists only information
about kmem caches that have child memcg kmem caches. Information
available in /proc/slabinfo are not repeated in memcg_slabinfo.
A portion of a sample output of the file was:
# <name> <css_id[:dead]> <active_objs> <num_objs> <active_slabs> <num_slabs>
rpc_inode_cache root 13 51 1 1
rpc_inode_cache 48 0 0 0 0
fat_inode_cache root 1 45 1 1
fat_inode_cache 41 2 45 1 1
xfs_inode root 770 816 24 24
xfs_inode 92 22 34 1 1
xfs_inode 88:dead 1 34 1 1
xfs_inode 89:dead 23 34 1 1
xfs_inode 85 4 34 1 1
xfs_inode 84 9 34 1 1
The css id of the memcg is also listed. If a memcg is not online,
the tag ":dead" will be attached as shown above.
[longman@redhat.com: memcg: add ":deact" tag for reparented kmem caches in memcg_slabinfo]
Link: http://lkml.kernel.org/r/20190621173005.31514-1-longman@redhat.com
[longman@redhat.com: set the flag in the common code as suggested by Roman]
Link: http://lkml.kernel.org/r/20190627184324.5875-1-longman@redhat.com
Link: http://lkml.kernel.org/r/20190619171621.26209-1-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Suggested-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let's reparent non-root kmem_caches on memcg offlining. This allows us to
release the memory cgroup without waiting for the last outstanding kernel
object (e.g. dentry used by another application).
Since the parent cgroup is already charged, everything we need to do is to
splice the list of kmem_caches to the parent's kmem_caches list, swap the
memcg pointer, drop the css refcounter for each kmem_cache and adjust the
parent's css refcounter.
Please, note that kmem_cache->memcg_params.memcg isn't a stable pointer
anymore. It's safe to read it under rcu_read_lock(), cgroup_mutex held,
or any other way that protects the memory cgroup from being released.
We can race with the slab allocation and deallocation paths. It's not a
big problem: parent's charge and slab global stats are always correct, and
we don't care anymore about the child usage and global stats. The child
cgroup is already offline, so we don't use or show it anywhere.
Local slab stats (NR_SLAB_RECLAIMABLE and NR_SLAB_UNRECLAIMABLE) aren't
used anywhere except count_shadow_nodes(). But even there it won't break
anything: after reparenting "nodes" will be 0 on child level (because
we're already reparenting shrinker lists), and on parent level page stats
always were 0, and this patch won't change anything.
[guro@fb.com: properly handle kmem_caches reparented to root_mem_cgroup]
Link: http://lkml.kernel.org/r/20190620213427.1691847-1-guro@fb.com
Link: http://lkml.kernel.org/r/20190611231813.3148843-11-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Waiman Long <longman@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Every slab page charged to a non-root memory cgroup has a pointer to the
memory cgroup and holds a reference to it, which protects a non-empty
memory cgroup from being released. At the same time the page has a
pointer to the corresponding kmem_cache, and also hold a reference to the
kmem_cache. And kmem_cache by itself holds a reference to the cgroup.
So there is clearly some redundancy, which allows to stop setting the
page->mem_cgroup pointer and rely on getting memcg pointer indirectly via
kmem_cache. Further it will allow to change this pointer easier, without
a need to go over all charged pages.
So let's stop setting page->mem_cgroup pointer for slab pages, and stop
using the css refcounter directly for protecting the memory cgroup from
going away. Instead rely on kmem_cache as an intermediate object.
Make sure that vmstats and shrinker lists are working as previously, as
well as /proc/kpagecgroup interface.
Link: http://lkml.kernel.org/r/20190611231813.3148843-10-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Waiman Long <longman@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently each charged slab page holds a reference to the cgroup to which
it's charged. Kmem_caches are held by the memcg and are released all
together with the memory cgroup. It means that none of kmem_caches are
released unless at least one reference to the memcg exists, which is very
far from optimal.
Let's rework it in a way that allows releasing individual kmem_caches as
soon as the cgroup is offline, the kmem_cache is empty and there are no
pending allocations.
To make it possible, let's introduce a new percpu refcounter for non-root
kmem caches. The counter is initialized to the percpu mode, and is
switched to the atomic mode during kmem_cache deactivation. The counter
is bumped for every charged page and also for every running allocation.
So the kmem_cache can't be released unless all allocations complete.
To shutdown non-active empty kmem_caches, let's reuse the work queue,
previously used for the kmem_cache deactivation. Once the reference
counter reaches 0, let's schedule an asynchronous kmem_cache release.
* I used the following simple approach to test the performance
(stolen from another patchset by T. Harding):
time find / -name fname-no-exist
echo 2 > /proc/sys/vm/drop_caches
repeat 10 times
Results:
orig patched
real 0m1.455s real 0m1.355s
user 0m0.206s user 0m0.219s
sys 0m0.855s sys 0m0.807s
real 0m1.487s real 0m1.699s
user 0m0.221s user 0m0.256s
sys 0m0.806s sys 0m0.948s
real 0m1.515s real 0m1.505s
user 0m0.183s user 0m0.215s
sys 0m0.876s sys 0m0.858s
real 0m1.291s real 0m1.380s
user 0m0.193s user 0m0.198s
sys 0m0.843s sys 0m0.786s
real 0m1.364s real 0m1.374s
user 0m0.180s user 0m0.182s
sys 0m0.868s sys 0m0.806s
real 0m1.352s real 0m1.312s
user 0m0.201s user 0m0.212s
sys 0m0.820s sys 0m0.761s
real 0m1.302s real 0m1.349s
user 0m0.205s user 0m0.203s
sys 0m0.803s sys 0m0.792s
real 0m1.334s real 0m1.301s
user 0m0.194s user 0m0.201s
sys 0m0.806s sys 0m0.779s
real 0m1.426s real 0m1.434s
user 0m0.216s user 0m0.181s
sys 0m0.824s sys 0m0.864s
real 0m1.350s real 0m1.295s
user 0m0.200s user 0m0.190s
sys 0m0.842s sys 0m0.811s
So it looks like the difference is not noticeable in this test.
[cai@lca.pw: fix an use-after-free in kmemcg_workfn()]
Link: http://lkml.kernel.org/r/1560977573-10715-1-git-send-email-cai@lca.pw
Link: http://lkml.kernel.org/r/20190611231813.3148843-9-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Waiman Long <longman@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently the memcg_params.dying flag and the corresponding workqueue used
for the asynchronous deactivation of kmem_caches is synchronized using the
slab_mutex.
It makes impossible to check this flag from the irq context, which will be
required in order to implement asynchronous release of kmem_caches.
So let's switch over to the irq-save flavor of the spinlock-based
synchronization.
Link: http://lkml.kernel.org/r/20190611231813.3148843-8-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Waiman Long <longman@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is no point in checking the root_cache->memcg_params.dying flag on
kmem_cache creation path. New allocations shouldn't be performed using a
dead root kmem_cache, so no new memcg kmem_cache creation can be scheduled
after the flag is set. And if it was scheduled before,
flush_memcg_workqueue() will wait for it anyway.
So let's drop this check to simplify the code.
Link: http://lkml.kernel.org/r/20190611231813.3148843-7-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Waiman Long <longman@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently the page accounting code is duplicated in SLAB and SLUB
internals. Let's move it into new (un)charge_slab_page helpers in the
slab_common.c file. These helpers will be responsible for statistics
(global and memcg-aware) and memcg charging. So they are replacing direct
memcg_(un)charge_slab() calls.
Link: http://lkml.kernel.org/r/20190611231813.3148843-6-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Waiman Long <longman@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let's separate the page counter modification code out of
__memcg_kmem_uncharge() in a way similar to what
__memcg_kmem_charge() and __memcg_kmem_charge_memcg() work.
This will allow to reuse this code later using a new
memcg_kmem_uncharge_memcg() wrapper, which calls
__memcg_kmem_uncharge_memcg() if memcg_kmem_enabled()
check is passed.
Link: http://lkml.kernel.org/r/20190611231813.3148843-5-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Waiman Long <longman@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently SLUB uses a work scheduled after an RCU grace period to
deactivate a non-root kmem_cache. This mechanism can be reused for
kmem_caches release, but requires generalization for SLAB case.
Introduce kmemcg_cache_deactivate() function, which calls
allocator-specific __kmem_cache_deactivate() and schedules execution of
__kmem_cache_deactivate_after_rcu() with all necessary locks in a worker
context after an rcu grace period.
Here is the new calling scheme:
kmemcg_cache_deactivate()
__kmemcg_cache_deactivate() SLAB/SLUB-specific
kmemcg_rcufn() rcu
kmemcg_workfn() work
__kmemcg_cache_deactivate_after_rcu() SLAB/SLUB-specific
instead of:
__kmemcg_cache_deactivate() SLAB/SLUB-specific
slab_deactivate_memcg_cache_rcu_sched() SLUB-only
kmemcg_rcufn() rcu
kmemcg_workfn() work
kmemcg_cache_deact_after_rcu() SLUB-only
For consistency, all allocator-specific functions start with "__".
Link: http://lkml.kernel.org/r/20190611231813.3148843-4-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Waiman Long <longman@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The delayed work/rcu deactivation infrastructure of non-root kmem_caches
can be also used for asynchronous release of these objects. Let's get rid
of the word "deactivation" in corresponding names to make the code look
better after generalization.
It's easier to make the renaming first, so that the generalized code will
look consistent from scratch.
Let's rename struct memcg_cache_params fields:
deact_fn -> work_fn
deact_rcu_head -> rcu_head
deact_work -> work
And RCU/delayed work callbacks in slab common code:
kmemcg_deactivate_rcufn -> kmemcg_rcufn
kmemcg_deactivate_workfn -> kmemcg_workfn
This patch contains no functional changes, only renamings.
Link: http://lkml.kernel.org/r/20190611231813.3148843-3-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Waiman Long <longman@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm: reparent slab memory on cgroup removal", v7.
# Why do we need this?
We've noticed that the number of dying cgroups is steadily growing on most
of our hosts in production. The following investigation revealed an issue
in the userspace memory reclaim code [1], accounting of kernel stacks [2],
and also the main reason: slab objects.
The underlying problem is quite simple: any page charged to a cgroup holds
a reference to it, so the cgroup can't be reclaimed unless all charged
pages are gone. If a slab object is actively used by other cgroups, it
won't be reclaimed, and will prevent the origin cgroup from being
reclaimed.
Slab objects, and first of all vfs cache, is shared between cgroups, which
are using the same underlying fs, and what's even more important, it's
shared between multiple generations of the same workload. So if something
is running periodically every time in a new cgroup (like how systemd
works), we do accumulate multiple dying cgroups.
Strictly speaking pagecache isn't different here, but there is a key
difference: we disable protection and apply some extra pressure on LRUs of
dying cgroups, and these LRUs contain all charged pages. My experiments
show that with the disabled kernel memory accounting the number of dying
cgroups stabilizes at a relatively small number (~100, depends on memory
pressure and cgroup creation rate), and with kernel memory accounting it
grows pretty steadily up to several thousands.
Memory cgroups are quite complex and big objects (mostly due to percpu
stats), so it leads to noticeable memory losses. Memory occupied by dying
cgroups is measured in hundreds of megabytes. I've even seen a host with
more than 100Gb of memory wasted for dying cgroups. It leads to a
degradation of performance with the uptime, and generally limits the usage
of cgroups.
My previous attempt [3] to fix the problem by applying extra pressure on
slab shrinker lists caused a regressions with xfs and ext4, and has been
reverted [4]. The following attempts to find the right balance [5, 6]
were not successful.
So instead of trying to find a maybe non-existing balance, let's do
reparent accounted slab caches to the parent cgroup on cgroup removal.
# Implementation approach
There is however a significant problem with reparenting of slab memory:
there is no list of charged pages. Some of them are in shrinker lists,
but not all. Introducing of a new list is really not an option.
But fortunately there is a way forward: every slab page has a stable
pointer to the corresponding kmem_cache. So the idea is to reparent
kmem_caches instead of slab pages.
It's actually simpler and cheaper, but requires some underlying changes:
1) Make kmem_caches to hold a single reference to the memory cgroup,
instead of a separate reference per every slab page.
2) Stop setting page->mem_cgroup pointer for memcg slab pages and use
page->kmem_cache->memcg indirection instead. It's used only on
slab page release, so performance overhead shouldn't be a big issue.
3) Introduce a refcounter for non-root slab caches. It's required to
be able to destroy kmem_caches when they become empty and release
the associated memory cgroup.
There is a bonus: currently we release all memcg kmem_caches all together
with the memory cgroup itself. This patchset allows individual
kmem_caches to be released as soon as they become inactive and free.
Some additional implementation details are provided in corresponding
commit messages.
# Results
Below is the average number of dying cgroups on two groups of our
production hosts. They do run some sort of web frontend workload, the
memory pressure is moderate. As we can see, with the kernel memory
reparenting the number stabilizes in 60s range; however with the original
version it grows almost linearly and doesn't show any signs of plateauing.
The difference in slab and percpu usage between patched and unpatched
versions also grows linearly. In 7 days it exceeded 200Mb.
day 0 1 2 3 4 5 6 7
original 56 362 628 752 1070 1250 1490 1560
patched 23 46 51 55 60 57 67 69
mem diff(Mb) 22 74 123 152 164 182 214 241
# Links
[1]: commit 68600f623d ("mm: don't miss the last page because of round-off error")
[2]: commit 9b6f7e163c ("mm: rework memcg kernel stack accounting")
[3]: commit 172b06c32b ("mm: slowly shrink slabs with a relatively small number of objects")
[4]: commit a9a238e83f ("Revert "mm: slowly shrink slabs with a relatively small number of objects")
[5]: https://lkml.org/lkml/2019/1/28/1865
[6]: https://marc.info/?l=linux-mm&m=155064763626437&w=2
This patch (of 10):
Initialize kmem_cache->memcg_params.memcg pointer in memcg_link_cache()
rather than in init_memcg_params().
Once kmem_cache will hold a reference to the memory cgroup, it will
simplify the refcounting.
For non-root kmem_caches memcg_link_cache() is always called before the
kmem_cache becomes visible to a user, so it's safe.
Link: http://lkml.kernel.org/r/20190611231813.3148843-2-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The memory controller in cgroup v2 exposes memory.events file for each
memcg which shows the number of times events like low, high, max, oom
and oom_kill have happened for the whole tree rooted at that memcg.
Users can also poll or register notification to monitor the changes in
that file. Any event at any level of the tree rooted at memcg will
notify all the listeners along the path till root_mem_cgroup. There are
existing users which depend on this behavior.
However there are users which are only interested in the events
happening at a specific level of the memcg tree and not in the events in
the underlying tree rooted at that memcg. One such use-case is a
centralized resource monitor which can dynamically adjust the limits of
the jobs running on a system. The jobs can create their sub-hierarchy
for their own sub-tasks. The centralized monitor is only interested in
the events at the top level memcgs of the jobs as it can then act and
adjust the limits of the jobs. Using the current memory.events for such
centralized monitor is very inconvenient. The monitor will keep
receiving events which it is not interested and to find if the received
event is interesting, it has to read memory.event files of the next
level and compare it with the top level one. So, let's introduce
memory.events.local to the memcg which shows and notify for the events
at the memcg level.
Now, does memory.stat and memory.pressure need their local versions. IMHO
no due to the no internal process contraint of the cgroup v2. The
memory.stat file of the top level memcg of a job shows the stats and
vmevents of the whole tree. The local stats or vmevents of the top level
memcg will only change if there is a process running in that memcg but v2
does not allow that. Similarly for memory.pressure there will not be any
process in the internal nodes and thus no chance of local pressure.
Link: http://lkml.kernel.org/r/20190527174643.209172-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Chris Down <chris@chrisdown.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The documentation of __GFP_RETRY_MAYFAIL clearly mentioned that the OOM
killer will not be triggered and indeed the page alloc does not invoke OOM
killer for such allocations. However we do trigger memcg OOM killer for
__GFP_RETRY_MAYFAIL. Fix that. This flag will used later to not trigger
oom-killer in the charging path for fanotify and inotify event
allocations.
Link: http://lkml.kernel.org/r/20190514212259.156585-1-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Via commit 4b3ef9daa4 ("mm/swap: split swap cache into 64MB trunks"),
after swapoff, the address_space associated with the swap device will be
freed. So swap_address_space() users which touch the address_space need
some kind of mechanism to prevent the address_space from being freed
during accessing.
When mincore processes an unmapped range for swapped shmem pages, it
doesn't hold the lock to prevent swap device from being swapped off. So
the following race is possible:
CPU1 CPU2
do_mincore() swapoff()
walk_page_range()
mincore_unmapped_range()
__mincore_unmapped_range
mincore_page
as = swap_address_space()
... exit_swap_address_space()
... kvfree(spaces)
find_get_page(as)
The address space may be accessed after being freed.
To fix the race, get_swap_device()/put_swap_device() is used to enclose
find_get_page() to check whether the swap entry is valid and prevent the
swap device from being swapoff during accessing.
Link: http://lkml.kernel.org/r/20190611020510.28251-1-ying.huang@intel.com
Fixes: 4b3ef9daa4 ("mm/swap: split swap cache into 64MB trunks")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Andrea Parri <andrea.parri@amarulasolutions.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
swap_extent is used to map swap page offset to backing device's block
offset. For a continuous block range, one swap_extent is used and all
these swap_extents are managed in a linked list.
These swap_extents are used by map_swap_entry() during swap's read and
write path. To find out the backing device's block offset for a page
offset, the swap_extent list will be traversed linearly, with
curr_swap_extent being used as a cache to speed up the search.
This works well as long as swap_extents are not huge or when the number
of processes that access swap device are few, but when the swap device
has many extents and there are a number of processes accessing the swap
device concurrently, it can be a problem. On one of our servers, the
disk's remaining size is tight:
$df -h
Filesystem Size Used Avail Use% Mounted on
... ...
/dev/nvme0n1p1 1.8T 1.3T 504G 72% /home/t4
When creating a 80G swapfile there, there are as many as 84656 swap
extents. The end result is, kernel spends abou 30% time in
map_swap_entry() and swap throughput is only 70MB/s.
As a comparison, when I used smaller sized swapfile, like 4G whose
swap_extent dropped to 2000, swap throughput is back to 400-500MB/s and
map_swap_entry() is about 3%.
One downside of using rbtree for swap_extent is, 'struct rbtree' takes
24 bytes while 'struct list_head' takes 16 bytes, that's 8 bytes more
for each swap_extent. For a swapfile that has 80k swap_extents, that
means 625KiB more memory consumed.
Test:
Since it's not possible to reboot that server, I can not test this patch
diretly there. Instead, I tested it on another server with NVMe disk.
I created a 20G swapfile on an NVMe backed XFS fs. By default, the
filesystem is quite clean and the created swapfile has only 2 extents.
Testing vanilla and this patch shows no obvious performance difference
when swapfile is not fragmented.
To see the patch's effects, I used some tweaks to manually fragment the
swapfile by breaking the extent at 1M boundary. This made the swapfile
have 20K extents.
nr_task=4
kernel swapout(KB/s) map_swap_entry(perf) swapin(KB/s) map_swap_entry(perf)
vanilla 165191 90.77% 171798 90.21%
patched 858993 +420% 2.16% 715827 +317% 0.77%
nr_task=8
kernel swapout(KB/s) map_swap_entry(perf) swapin(KB/s) map_swap_entry(perf)
vanilla 306783 92.19% 318145 87.76%
patched 954437 +211% 2.35% 1073741 +237% 1.57%
swapout: the throughput of swap out, in KB/s, higher is better 1st
map_swap_entry: cpu cycles percent sampled by perf swapin: the
throughput of swap in, in KB/s, higher is better. 2nd map_swap_entry:
cpu cycles percent sampled by perf
nr_task=1 doesn't show any difference, this is due to the curr_swap_extent
can be effectively used to cache the correct swap extent for single task
workload.
[akpm@linux-foundation.org: s/BUG_ON(1)/BUG()/]
Link: http://lkml.kernel.org/r/20190523142404.GA181@aaronlu
Signed-off-by: Aaron Lu <ziqian.lzq@antfin.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
total_swapcache_pages() may race with swapper_spaces[] allocation and
freeing. Previously, this is protected with a swapper_spaces[] specific
RCU mechanism. To simplify the logic/code complexity, it is replaced with
get/put_swap_device(). The code line number is reduced too. Although not
so important, the swapoff() performance improves too because one
synchronize_rcu() call during swapoff() is deleted.
[ying.huang@intel.com: fix bad swap file entry warning]
Link: http://lkml.kernel.org/r/20190531024102.21723-1-ying.huang@intel.com
Link: http://lkml.kernel.org/r/20190527082714.12151-1-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Andrea Parri <andrea.parri@amarulasolutions.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When swapin is performed, after getting the swap entry information from
the page table, system will swap in the swap entry, without any lock held
to prevent the swap device from being swapoff. This may cause the race
like below,
CPU 1 CPU 2
----- -----
do_swap_page
swapin_readahead
__read_swap_cache_async
swapoff swapcache_prepare
p->swap_map = NULL __swap_duplicate
p->swap_map[?] /* !!! NULL pointer access */
Because swapoff is usually done when system shutdown only, the race may
not hit many people in practice. But it is still a race need to be fixed.
To fix the race, get_swap_device() is added to check whether the specified
swap entry is valid in its swap device. If so, it will keep the swap
entry valid via preventing the swap device from being swapoff, until
put_swap_device() is called.
Because swapoff() is very rare code path, to make the normal path runs as
fast as possible, rcu_read_lock/unlock() and synchronize_rcu() instead of
reference count is used to implement get/put_swap_device(). >From
get_swap_device() to put_swap_device(), RCU reader side is locked, so
synchronize_rcu() in swapoff() will wait until put_swap_device() is
called.
In addition to swap_map, cluster_info, etc. data structure in the struct
swap_info_struct, the swap cache radix tree will be freed after swapoff,
so this patch fixes the race between swap cache looking up and swapoff
too.
Races between some other swap cache usages and swapoff are fixed too via
calling synchronize_rcu() between clearing PageSwapCache() and freeing
swap cache data structure.
Another possible method to fix this is to use preempt_off() +
stop_machine() to prevent the swap device from being swapoff when its data
structure is being accessed. The overhead in hot-path of both methods is
similar. The advantages of RCU based method are,
1. stop_machine() may disturb the normal execution code path on other
CPUs.
2. File cache uses RCU to protect its radix tree. If the similar
mechanism is used for swap cache too, it is easier to share code
between them.
3. RCU is used to protect swap cache in total_swapcache_pages() and
exit_swap_address_space() already. The two mechanisms can be
merged to simplify the logic.
Link: http://lkml.kernel.org/r/20190522015423.14418-1-ying.huang@intel.com
Fixes: 235b621767 ("mm/swap: add cluster lock")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Andrea Parri <andrea.parri@amarulasolutions.com>
Not-nacked-by: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Yang Shi <yang.shi@linux.alibaba.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 6b4c9f4469 ("filemap: drop the mmap_sem for all blocking
operations") changed when mmap_sem is dropped during filemap page fault
and when returning VM_FAULT_RETRY.
Correct the comment to reflect the change.
Link: http://lkml.kernel.org/r/1556234531-108228-1-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We can just pass a NULL filler and do the right thing inside of
do_read_cache_page based on the NULL parameter.
Link: http://lkml.kernel.org/r/20190520055731.24538-3-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "fix filler_t callback type mismatches", v2.
Casting mapping->a_ops->readpage to filler_t causes an indirect call
type mismatch with Control-Flow Integrity checking. This change fixes
the mismatch in read_cache_page_gfp and read_mapping_page by adding
using a NULL filler argument as an indication to call ->readpage
directly, and by passing the right parameter callbacks in nfs and jffs2.
This patch (of 4):
Code cleanup.
Link: http://lkml.kernel.org/r/20190520055731.24538-2-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When debug_pagealloc is enabled, we currently allocate the page_ext
array to mark guard pages with the PAGE_EXT_DEBUG_GUARD flag. Now that
we have the page_type field in struct page, we can use that instead, as
guard pages are neither PageSlab nor mapped to userspace. This reduces
memory overhead when debug_pagealloc is enabled and there are no other
features requiring the page_ext array.
Link: http://lkml.kernel.org/r/20190603143451.27353-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The page allocator checks struct pages for expected state (mapcount,
flags etc) as pages are being allocated (check_new_page()) and freed
(free_pages_check()) to provide some defense against errors in page
allocator users.
Prior commits 479f854a20 ("mm, page_alloc: defer debugging checks of
pages allocated from the PCP") and 4db7548ccb ("mm, page_alloc: defer
debugging checks of freed pages until a PCP drain") this has happened
for order-0 pages as they were allocated from or freed to the per-cpu
caches (pcplists). Since those are fast paths, the checks are now
performed only when pages are moved between pcplists and global free
lists. This however lowers the chances of catching errors soon enough.
In order to increase the chances of the checks to catch errors, the
kernel has to be rebuilt with CONFIG_DEBUG_VM, which also enables
multiple other internal debug checks (VM_BUG_ON() etc), which is
suboptimal when the goal is to catch errors in mm users, not in mm code
itself.
To catch some wrong users of the page allocator we have
CONFIG_DEBUG_PAGEALLOC, which is designed to have virtually no overhead
unless enabled at boot time. Memory corruptions when writing to freed
pages have often the same underlying errors (use-after-free, double free)
as corrupting the corresponding struct pages, so this existing debugging
functionality is a good fit to extend by also perform struct page checks
at least as often as if CONFIG_DEBUG_VM was enabled.
Specifically, after this patch, when debug_pagealloc is enabled on boot,
and CONFIG_DEBUG_VM disabled, pages are checked when allocated from or
freed to the pcplists *in addition* to being moved between pcplists and
free lists. When both debug_pagealloc and CONFIG_DEBUG_VM are enabled,
pages are checked when being moved between pcplists and free lists *in
addition* to when allocated from or freed to the pcplists.
When debug_pagealloc is not enabled on boot, the overhead in fast paths
should be virtually none thanks to the use of static key.
Link: http://lkml.kernel.org/r/20190603143451.27353-3-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "debug_pagealloc improvements".
I have been recently debugging some pcplist corruptions, where it would be
useful to perform struct page checks immediately as pages are allocated
from and freed to pcplists, which is now only possible by rebuilding the
kernel with CONFIG_DEBUG_VM (details in Patch 2 changelog).
To make this kind of debugging simpler in future on a distro kernel, I
have improved CONFIG_DEBUG_PAGEALLOC so that it has even smaller overhead
when not enabled at boot time (Patch 1) and also when enabled (Patch 3),
and extended it to perform the struct page checks more often when enabled
(Patch 2). Now it can be configured in when building a distro kernel
without extra overhead, and debugging page use after free or double free
can be enabled simply by rebooting with debug_pagealloc=on.
This patch (of 3):
CONFIG_DEBUG_PAGEALLOC has been redesigned by 031bc5743f
("mm/debug-pagealloc: make debug-pagealloc boottime configurable") to
allow being always enabled in a distro kernel, but only perform its
expensive functionality when booted with debug_pagelloc=on. We can
further reduce the overhead when not boot-enabled (including page
allocator fast paths) using static keys. This patch introduces one for
debug_pagealloc core functionality, and another for the optional guard
page functionality (enabled by booting with debug_guardpage_minorder=X).
Link: http://lkml.kernel.org/r/20190603143451.27353-2-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When failslab was originally written, the intention of the
"ignore-gfp-wait" flag default value ("N") was to fail GFP_ATOMIC
allocations. Those were defined as (__GFP_HIGH), and the code would test
for __GFP_WAIT (0x10u).
However, since then, __GFP_WAIT was replaced by __GFP_RECLAIM
(___GFP_DIRECT_RECLAIM|___GFP_KSWAPD_RECLAIM), and GFP_ATOMIC is now
defined as (__GFP_HIGH|__GFP_ATOMIC|__GFP_KSWAPD_RECLAIM).
This means that when the flag is false, almost no allocation ever fails
(as even GFP_ATOMIC allocations contain ___GFP_KSWAPD_RECLAIM).
Restore the original intent of the code, by ignoring calls that directly
reclaim only (__GFP_DIRECT_RECLAIM), and thus, failing GFP_ATOMIC calls
again by default.
Link: http://lkml.kernel.org/r/20190520214514.81360-1-drinkcat@chromium.org
Fixes: 71baba4b92 ("mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM")
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Previously totalram_pages was the global variable. Currently,
totalram_pages is the static inline function from the include/linux/mm.h
However, the function is also marked as EXPORT_SYMBOL, which is at best an
odd combination. Because there is no point for the static inline function
from a public header to be exported, this commit removes the
EXPORT_SYMBOL() marking. It will be still possible to use the function in
modules because all the symbols it depends on are exported.
Link: http://lkml.kernel.org/r/20190710141031.15642-1-efremov@linux.com
Fixes: ca79b0c211 ("mm: convert totalram_pages and totalhigh_pages variables to atomic")
Signed-off-by: Denis Efremov <efremov@linux.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pavel.tatashin@microsoft.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
undo_isolate_page_range() never fails, so no need to return value.
Link: http://lkml.kernel.org/r/1562075604-8979-1-git-send-email-kernelfans@gmail.com
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
account_page_dirtied() is only used by our set_page_dirty() helpers and
should not be used anywhere else.
Link: http://lkml.kernel.org/r/20190605183702.30572-1-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make the success case use the same cleanup path as the failure case.
Link: http://lkml.kernel.org/r/20190523134024.GC24093@localhost.localdomain
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
follow_page_mask() is only used in gup.c, make it static.
Link: http://lkml.kernel.org/r/20190510190831.GA4061@bharath12345-Inspiron-5559
Signed-off-by: Bharath Vedartham <linux.bhar@gmail.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
ksize() has been unconditionally unpoisoning the whole shadow memory
region associated with an allocation. This can lead to various undetected
bugs, for example, double-kzfree().
Specifically, kzfree() uses ksize() to determine the actual allocation
size, and subsequently zeroes the memory. Since ksize() used to just
unpoison the whole shadow memory region, no invalid free was detected.
This patch addresses this as follows:
1. Add a check in ksize(), and only then unpoison the memory region.
2. Preserve kasan_unpoison_slab() semantics by explicitly unpoisoning
the shadow memory region using the size obtained from __ksize().
Tested:
1. With SLAB allocator: a) normal boot without warnings; b) verified the
added double-kzfree() is detected.
2. With SLUB allocator: a) normal boot without warnings; b) verified the
added double-kzfree() is detected.
[elver@google.com: s/BUG_ON/WARN_ON_ONCE/, per Kees]
Link: http://lkml.kernel.org/r/20190627094445.216365-6-elver@google.com
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199359
Link: http://lkml.kernel.org/r/20190626142014.141844-6-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This refactors common code of ksize() between the various allocators into
slab_common.c: __ksize() is the allocator-specific implementation without
instrumentation, whereas ksize() includes the required KASAN logic.
Link: http://lkml.kernel.org/r/20190626142014.141844-5-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This changes {,__}kasan_check_{read,write} functions to return a boolean
denoting if the access was valid or not.
[sfr@canb.auug.org.au: include types.h for "bool"]
Link: http://lkml.kernel.org/r/20190705184949.13cdd021@canb.auug.org.au
Link: http://lkml.kernel.org/r/20190626142014.141844-3-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/kasan: Add object validation in ksize()", v3.
This patch (of 5):
This introduces __kasan_check_{read,write}. __kasan_check functions may
be used from anywhere, even compilation units that disable instrumentation
selectively.
This change eliminates the need for the __KASAN_INTERNAL definition.
[elver@google.com: v5]
Link: http://lkml.kernel.org/r/20190708170706.174189-2-elver@google.com
Link: http://lkml.kernel.org/r/20190626142014.141844-2-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds support for printing stack frame description on invalid stack
accesses. The frame description is embedded by the compiler, which is
parsed and then pretty-printed.
Currently, we can only print the stack frame info for accesses to the
task's own stack, but not accesses to other tasks' stacks.
Example of what it looks like:
page dumped because: kasan: bad access detected
addr ffff8880673ef98a is located in stack of task insmod/2008 at offset 106 in frame:
kasan_stack_oob+0x0/0xf5 [test_kasan]
this frame has 2 objects:
[32, 36) 'i'
[96, 106) 'stack_array'
Memory state around the buggy address:
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=198435
Link: http://lkml.kernel.org/r/20190522100048.146841-1-elver@google.com
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
According to POSIX, EBUSY means that the "device or resource is busy", and
this can lead to people thinking that the file
`/sys/kernel/debug/kmemleak/` is somehow locked or being used by other
process. Change this error code to a more appropriate one.
Link: http://lkml.kernel.org/r/20190612155231.19448-1-andrealmeid@collabora.com
Signed-off-by: André Almeida <andrealmeid@collabora.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently for CONFIG_SLUB, if a memcg kmem cache creation is failed and
the corresponding root kmem cache has SLAB_PANIC flag, the kernel will
be crashed. This is unnecessary as the kernel can handle the creation
failures of memcg kmem caches. Additionally CONFIG_SLAB does not
implement this behavior. So, to keep the behavior consistent between
SLAB and SLUB, removing the panic for memcg kmem cache creation
failures. The root kmem cache creation failure for SLAB_PANIC correctly
panics for both SLAB and SLUB.
Link: http://lkml.kernel.org/r/20190619232514.58994-1-shakeelb@google.com
Reported-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If ',' is not found, kmem_cache_flags() calls strlen() to find the end of
line. We can do it in a single pass using strchrnul().
Link: http://lkml.kernel.org/r/20190501053111.7950-1-ynorov@marvell.com
Signed-off-by: Yury Norov <ynorov@marvell.com>
Acked-by: Aaron Tomlin <atomlin@redhat.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This avoids any possible type confusion when looking up an object. For
example, if a non-slab were to be passed to kfree(), the invalid
slab_cache pointer (i.e. overlapped with some other value from the
struct page union) would be used for subsequent slab manipulations that
could lead to further memory corruption.
Since the page is already in cache, adding the PageSlab() check will
have nearly zero cost, so add a check and WARN() to virt_to_cache().
Additionally replaces an open-coded virt_to_cache(). To support the
failure mode this also updates all callers of virt_to_cache() and
cache_from_obj() to handle a NULL cache pointer return value (though
note that several already handle this case gracefully).
[dan.carpenter@oracle.com: restore IRQs in kfree()]
Link: http://lkml.kernel.org/r/20190613065637.GE16334@mwanda
Link: http://lkml.kernel.org/r/20190530045017.15252-3-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm/slab: Improved sanity checking".
This adds defenses against slab cache confusion (as seen in real-world
exploits[1]) and gracefully handles type confusions when trying to look
up slab caches from an arbitrary page. (Also is patch 3: new LKDTM
tests for these defenses as well as for the existing double-free
detection.
This patch (of 3):
When building under CONFIG_SLAB_FREELIST_HARDENING, it makes sense to
perform sanity-checking on the assumed slab cache during
kmem_cache_free() to make sure the kernel doesn't mix freelists across
slab caches and corrupt memory (as seen in the exploitation of flaws
like CVE-2018-9568[1]). Note that the prior code might WARN() but still
corrupt memory (i.e. return the assumed cache instead of the owned
cache).
There is no noticeable performance impact (changes are within noise).
Measuring parallel kernel builds, I saw the following with
CONFIG_SLAB_FREELIST_HARDENED, before and after this patch:
before:
Run times: 288.85 286.53 287.09 287.07 287.21
Min: 286.53 Max: 288.85 Mean: 287.35 Std Dev: 0.79
after:
Run times: 289.58 287.40 286.97 287.20 287.01
Min: 286.97 Max: 289.58 Mean: 287.63 Std Dev: 0.99
Delta: 0.1% which is well below the standard deviation
[1] https://github.com/ThomasKing2014/slides/raw/master/Building%20universal%20Android%20rooting%20with%20a%20type%20confusion%20vulnerability.pdf
Link: http://lkml.kernel.org/r/20190530045017.15252-2-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Popov <alex.popov@linux.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Following zsmalloc.c's example we call trylock_page() and unlock_page().
Also make z3fold_page_migrate() assert that newpage is passed in locked,
as per the documentation.
[akpm@linux-foundation.org: fix trylock_page return value test, per Shakeel]
Link: http://lkml.kernel.org/r/20190702005122.41036-1-henryburns@google.com
Link: http://lkml.kernel.org/r/20190702233538.52793-1-henryburns@google.com
Signed-off-by: Henry Burns <henryburns@google.com>
Suggested-by: Vitaly Wool <vitalywool@gmail.com>
Acked-by: Vitaly Wool <vitalywool@gmail.com>
Acked-by: David Rientjes <rientjes@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Vitaly Vul <vitaly.vul@sony.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Xidong Wang <wangxidong_97@163.com>
Cc: Jonathan Adams <jwadams@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When we calculate total statistics for memcg1_stats and memcg1_events,
we use the the index 'i' in the for loop as the events index. Actually
we should use memcg1_stats[i] and memcg1_events[i] as the events index.
Link: http://lkml.kernel.org/r/1562116978-19539-1-git-send-email-laoar.shao@gmail.com
Fixes: 42a3003535 ("mm: memcontrol: fix recursive statistics correctness & scalabilty").
Signed-off-by: Yafang Shao <laoar.shao@gmail.com
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yafang Shao <shaoyafang@didiglobal.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When file refaults are detected and there are many inactive file pages,
the system never reclaim anonymous pages, the file pages are dropped
aggressively when there are still a lot of cold anonymous pages and
system thrashes. This issue impacts the performance of applications
with large executable, e.g. chrome.
With this patch, when file refault is detected, inactive_list_is_low()
always returns true for file pages in get_scan_count() to enable
scanning anonymous pages.
The problem can be reproduced by the following test program.
---8<---
void fallocate_file(const char *filename, off_t size)
{
struct stat st;
int fd;
if (!stat(filename, &st) && st.st_size >= size)
return;
fd = open(filename, O_WRONLY | O_CREAT, 0600);
if (fd < 0) {
perror("create file");
exit(1);
}
if (posix_fallocate(fd, 0, size)) {
perror("fallocate");
exit(1);
}
close(fd);
}
long *alloc_anon(long size)
{
long *start = malloc(size);
memset(start, 1, size);
return start;
}
long access_file(const char *filename, long size, long rounds)
{
int fd, i;
volatile char *start1, *end1, *start2;
const int page_size = getpagesize();
long sum = 0;
fd = open(filename, O_RDONLY);
if (fd == -1) {
perror("open");
exit(1);
}
/*
* Some applications, e.g. chrome, use a lot of executable file
* pages, map some of the pages with PROT_EXEC flag to simulate
* the behavior.
*/
start1 = mmap(NULL, size / 2, PROT_READ | PROT_EXEC, MAP_SHARED,
fd, 0);
if (start1 == MAP_FAILED) {
perror("mmap");
exit(1);
}
end1 = start1 + size / 2;
start2 = mmap(NULL, size / 2, PROT_READ, MAP_SHARED, fd, size / 2);
if (start2 == MAP_FAILED) {
perror("mmap");
exit(1);
}
for (i = 0; i < rounds; ++i) {
struct timeval before, after;
volatile char *ptr1 = start1, *ptr2 = start2;
gettimeofday(&before, NULL);
for (; ptr1 < end1; ptr1 += page_size, ptr2 += page_size)
sum += *ptr1 + *ptr2;
gettimeofday(&after, NULL);
printf("File access time, round %d: %f (sec)
", i,
(after.tv_sec - before.tv_sec) +
(after.tv_usec - before.tv_usec) / 1000000.0);
}
return sum;
}
int main(int argc, char *argv[])
{
const long MB = 1024 * 1024;
long anon_mb, file_mb, file_rounds;
const char filename[] = "large";
long *ret1;
long ret2;
if (argc != 4) {
printf("usage: thrash ANON_MB FILE_MB FILE_ROUNDS
");
exit(0);
}
anon_mb = atoi(argv[1]);
file_mb = atoi(argv[2]);
file_rounds = atoi(argv[3]);
fallocate_file(filename, file_mb * MB);
printf("Allocate %ld MB anonymous pages
", anon_mb);
ret1 = alloc_anon(anon_mb * MB);
printf("Access %ld MB file pages
", file_mb);
ret2 = access_file(filename, file_mb * MB, file_rounds);
printf("Print result to prevent optimization: %ld
",
*ret1 + ret2);
return 0;
}
---8<---
Running the test program on 2GB RAM VM with kernel 5.2.0-rc5, the program
fills ram with 2048 MB memory, access a 200 MB file for 10 times. Without
this patch, the file cache is dropped aggresively and every access to the
file is from disk.
$ ./thrash 2048 200 10
Allocate 2048 MB anonymous pages
Access 200 MB file pages
File access time, round 0: 2.489316 (sec)
File access time, round 1: 2.581277 (sec)
File access time, round 2: 2.487624 (sec)
File access time, round 3: 2.449100 (sec)
File access time, round 4: 2.420423 (sec)
File access time, round 5: 2.343411 (sec)
File access time, round 6: 2.454833 (sec)
File access time, round 7: 2.483398 (sec)
File access time, round 8: 2.572701 (sec)
File access time, round 9: 2.493014 (sec)
With this patch, these file pages can be cached.
$ ./thrash 2048 200 10
Allocate 2048 MB anonymous pages
Access 200 MB file pages
File access time, round 0: 2.475189 (sec)
File access time, round 1: 2.440777 (sec)
File access time, round 2: 2.411671 (sec)
File access time, round 3: 1.955267 (sec)
File access time, round 4: 0.029924 (sec)
File access time, round 5: 0.000808 (sec)
File access time, round 6: 0.000771 (sec)
File access time, round 7: 0.000746 (sec)
File access time, round 8: 0.000738 (sec)
File access time, round 9: 0.000747 (sec)
Checked the swap out stats during the test [1], 19006 pages swapped out
with this patch, 3418 pages swapped out without this patch. There are
more swap out, but I think it's within reasonable range when file backed
data set doesn't fit into the memory.
$ ./thrash 2000 100 2100 5 1 # ANON_MB FILE_EXEC FILE_NOEXEC ROUNDS
PROCESSES Allocate 2000 MB anonymous pages active_anon: 1613644,
inactive_anon: 348656, active_file: 892, inactive_file: 1384 (kB)
pswpout: 7972443, pgpgin: 478615246 Access 100 MB executable file pages
Access 2100 MB regular file pages File access time, round 0: 12.165,
(sec) active_anon: 1433788, inactive_anon: 478116, active_file: 17896,
inactive_file: 24328 (kB) File access time, round 1: 11.493, (sec)
active_anon: 1430576, inactive_anon: 477144, active_file: 25440,
inactive_file: 26172 (kB) File access time, round 2: 11.455, (sec)
active_anon: 1427436, inactive_anon: 476060, active_file: 21112,
inactive_file: 28808 (kB) File access time, round 3: 11.454, (sec)
active_anon: 1420444, inactive_anon: 473632, active_file: 23216,
inactive_file: 35036 (kB) File access time, round 4: 11.479, (sec)
active_anon: 1413964, inactive_anon: 471460, active_file: 31728,
inactive_file: 32224 (kB) pswpout: 7991449 (+ 19006), pgpgin: 489924366
(+ 11309120)
With 4 processes accessing non-overlapping parts of a large file, 30316
pages swapped out with this patch, 5152 pages swapped out without this
patch. The swapout number is small comparing to pgpgin.
[1]: https://github.com/vovo/testing/blob/master/mem_thrash.c
Link: http://lkml.kernel.org/r/20190701081038.GA83398@google.com
Fixes: e986850598 ("mm,vmscan: only evict file pages when we have plenty")
Fixes: 7c5bd705d8 ("mm: memcg: only evict file pages when we have plenty")
Signed-off-by: Kuo-Hsin Yang <vovoy@chromium.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Sonny Rao <sonnyrao@chromium.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: <stable@vger.kernel.org> [4.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Here is the "large" pull request for char and misc and other assorted
smaller driver subsystems for 5.3-rc1.
It seems that this tree is becoming the funnel point of lots of smaller
driver subsystems, which is fine for me, but that's why it is getting
larger over time and does not just contain stuff under drivers/char/ and
drivers/misc.
Lots of small updates all over the place here from different driver
subsystems:
- habana driver updates
- coresight driver updates
- documentation file movements and updates
- Android binder fixes and updates
- extcon driver updates
- google firmware driver updates
- fsi driver updates
- smaller misc and char driver updates
- soundwire driver updates
- nvmem driver updates
- w1 driver fixes
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc driver updates from Greg KH:
"Here is the "large" pull request for char and misc and other assorted
smaller driver subsystems for 5.3-rc1.
It seems that this tree is becoming the funnel point of lots of
smaller driver subsystems, which is fine for me, but that's why it is
getting larger over time and does not just contain stuff under
drivers/char/ and drivers/misc.
Lots of small updates all over the place here from different driver
subsystems:
- habana driver updates
- coresight driver updates
- documentation file movements and updates
- Android binder fixes and updates
- extcon driver updates
- google firmware driver updates
- fsi driver updates
- smaller misc and char driver updates
- soundwire driver updates
- nvmem driver updates
- w1 driver fixes
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (188 commits)
coresight: Do not default to CPU0 for missing CPU phandle
dt-bindings: coresight: Change CPU phandle to required property
ocxl: Allow contexts to be attached with a NULL mm
fsi: sbefifo: Don't fail operations when in SBE IPL state
coresight: tmc: Smatch: Fix potential NULL pointer dereference
coresight: etm3x: Smatch: Fix potential NULL pointer dereference
coresight: Potential uninitialized variable in probe()
coresight: etb10: Do not call smp_processor_id from preemptible
coresight: tmc-etf: Do not call smp_processor_id from preemptible
coresight: tmc-etr: alloc_perf_buf: Do not call smp_processor_id from preemptible
coresight: tmc-etr: Do not call smp_processor_id() from preemptible
docs: misc-devices: convert files without extension to ReST
fpga: dfl: fme: align PR buffer size per PR datawidth
fpga: dfl: fme: remove copy_to_user() in ioctl for PR
fpga: dfl-fme-mgr: fix FME_PR_INTFC_ID register address.
intel_th: msu: Start read iterator from a non-empty window
intel_th: msu: Split sgt array and pointer in multiwindow mode
intel_th: msu: Support multipage blocks
intel_th: pci: Add Ice Lake NNPI support
intel_th: msu: Fix single mode with disabled IOMMU
...
lookups.
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"Many bug fixes and cleanups, and an optimization for case-insensitive
lookups"
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix coverity warning on error path of filename setup
ext4: replace ktype default_attrs with default_groups
ext4: rename htree_inline_dir_to_tree() to ext4_inlinedir_to_tree()
ext4: refactor initialize_dirent_tail()
ext4: rename "dirent_csum" functions to use "dirblock"
ext4: allow directory holes
jbd2: drop declaration of journal_sync_buffer()
ext4: use jbd2_inode dirty range scoping
jbd2: introduce jbd2_inode dirty range scoping
mm: add filemap_fdatawait_range_keep_errors()
ext4: remove redundant assignment to node
ext4: optimize case-insensitive lookups
ext4: make __ext4_get_inode_loc plug
ext4: clean up kerneldoc warnigns when building with W=1
ext4: only set project inherit bit for directory
ext4: enforce the immutable flag on open files
ext4: don't allow any modifications to an immutable file
jbd2: fix typo in comment of journal_submit_inode_data_buffers
jbd2: fix some print format mistakes
ext4: gracefully handle ext4_break_layouts() failure during truncate
- Create a generic copy_file_range handler and make individual
filesystems responsible for calling it (i.e. no more assuming that
do_splice_direct will work or is appropriate)
- Refactor copy_file_range and remap_range parameter checking where they
are the same
- Install missing copy_file_range parameter checking(!)
- Remove suid/sgid and update mtime like any other file write
- Change the behavior so that a copy range crossing the source file's
eof will result in a short copy to the source file's eof instead of
EINVAL
- Permit filesystems to decide if they want to handle cross-superblock
copy_file_range in their local handlers.
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Merge tag 'copy-file-range-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull copy_file_range updates from Darrick Wong:
"This fixes numerous parameter checking problems and inconsistent
behaviors in the new(ish) copy_file_range system call.
Now the system call will actually check its range parameters
correctly; refuse to copy into files for which the caller does not
have sufficient privileges; update mtime and strip setuid like file
writes are supposed to do; and allows copying up to the EOF of the
source file instead of failing the call like we used to.
Summary:
- Create a generic copy_file_range handler and make individual
filesystems responsible for calling it (i.e. no more assuming that
do_splice_direct will work or is appropriate)
- Refactor copy_file_range and remap_range parameter checking where
they are the same
- Install missing copy_file_range parameter checking(!)
- Remove suid/sgid and update mtime like any other file write
- Change the behavior so that a copy range crossing the source file's
eof will result in a short copy to the source file's eof instead of
EINVAL
- Permit filesystems to decide if they want to handle
cross-superblock copy_file_range in their local handlers"
* tag 'copy-file-range-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
fuse: copy_file_range needs to strip setuid bits and update timestamps
vfs: allow copy_file_range to copy across devices
xfs: use file_modified() helper
vfs: introduce file_modified() helper
vfs: add missing checks to copy_file_range
vfs: remove redundant checks from generic_remap_checks()
vfs: introduce generic_file_rw_checks()
vfs: no fallback for ->copy_file_range
vfs: introduce generic_copy_file_range()
- A fair pile of RST conversions, many from Mauro. These create more
than the usual number of simple but annoying merge conflicts with other
trees, unfortunately. He has a lot more of these waiting on the wings
that, I think, will go to you directly later on.
- A new document on how to use merges and rebases in kernel repos, and one
on Spectre vulnerabilities.
- Various improvements to the build system, including automatic markup of
function() references because some people, for reasons I will never
understand, were of the opinion that :c:func:``function()`` is
unattractive and not fun to type.
- We now recommend using sphinx 1.7, but still support back to 1.4.
- Lots of smaller improvements, warning fixes, typo fixes, etc.
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Merge tag 'docs-5.3' of git://git.lwn.net/linux
Pull Documentation updates from Jonathan Corbet:
"It's been a relatively busy cycle for docs:
- A fair pile of RST conversions, many from Mauro. These create more
than the usual number of simple but annoying merge conflicts with
other trees, unfortunately. He has a lot more of these waiting on
the wings that, I think, will go to you directly later on.
- A new document on how to use merges and rebases in kernel repos,
and one on Spectre vulnerabilities.
- Various improvements to the build system, including automatic
markup of function() references because some people, for reasons I
will never understand, were of the opinion that
:c:func:``function()`` is unattractive and not fun to type.
- We now recommend using sphinx 1.7, but still support back to 1.4.
- Lots of smaller improvements, warning fixes, typo fixes, etc"
* tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits)
docs: automarkup.py: ignore exceptions when seeking for xrefs
docs: Move binderfs to admin-guide
Disable Sphinx SmartyPants in HTML output
doc: RCU callback locks need only _bh, not necessarily _irq
docs: format kernel-parameters -- as code
Doc : doc-guide : Fix a typo
platform: x86: get rid of a non-existent document
Add the RCU docs to the core-api manual
Documentation: RCU: Add TOC tree hooks
Documentation: RCU: Rename txt files to rst
Documentation: RCU: Convert RCU UP systems to reST
Documentation: RCU: Convert RCU linked list to reST
Documentation: RCU: Convert RCU basic concepts to reST
docs: filesystems: Remove uneeded .rst extension on toctables
scripts/sphinx-pre-install: fix out-of-tree build
docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/
Documentation: PGP: update for newer HW devices
Documentation: Add section about CPU vulnerabilities for Spectre
Documentation: platform: Delete x86-laptop-drivers.txt
docs: Note that :c:func: should no longer be used
...
Pull force_sig() argument change from Eric Biederman:
"A source of error over the years has been that force_sig has taken a
task parameter when it is only safe to use force_sig with the current
task.
The force_sig function is built for delivering synchronous signals
such as SIGSEGV where the userspace application caused a synchronous
fault (such as a page fault) and the kernel responded with a signal.
Because the name force_sig does not make this clear, and because the
force_sig takes a task parameter the function force_sig has been
abused for sending other kinds of signals over the years. Slowly those
have been fixed when the oopses have been tracked down.
This set of changes fixes the remaining abusers of force_sig and
carefully rips out the task parameter from force_sig and friends
making this kind of error almost impossible in the future"
* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits)
signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus
signal: Remove the signal number and task parameters from force_sig_info
signal: Factor force_sig_info_to_task out of force_sig_info
signal: Generate the siginfo in force_sig
signal: Move the computation of force into send_signal and correct it.
signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal
signal: Remove the task parameter from force_sig_fault
signal: Use force_sig_fault_to_task for the two calls that don't deliver to current
signal: Explicitly call force_sig_fault on current
signal/unicore32: Remove tsk parameter from __do_user_fault
signal/arm: Remove tsk parameter from __do_user_fault
signal/arm: Remove tsk parameter from ptrace_break
signal/nds32: Remove tsk parameter from send_sigtrap
signal/riscv: Remove tsk parameter from do_trap
signal/sh: Remove tsk parameter from force_sig_info_fault
signal/um: Remove task parameter from send_sigtrap
signal/x86: Remove task parameter from send_sigtrap
signal: Remove task parameter from force_sig_mceerr
signal: Remove task parameter from force_sig
signal: Remove task parameter from force_sigsegv
...
- arm64 support for syscall emulation via PTRACE_SYSEMU{,_SINGLESTEP}
- Wire up VM_FLUSH_RESET_PERMS for arm64, allowing the core code to
manage the permissions of executable vmalloc regions more strictly
- Slight performance improvement by keeping softirqs enabled while
touching the FPSIMD/SVE state (kernel_neon_begin/end)
- Expose a couple of ARMv8.5 features to user (HWCAP): CondM (new XAFLAG
and AXFLAG instructions for floating point comparison flags
manipulation) and FRINT (rounding floating point numbers to integers)
- Re-instate ARM64_PSEUDO_NMI support which was previously marked as
BROKEN due to some bugs (now fixed)
- Improve parking of stopped CPUs and implement an arm64-specific
panic_smp_self_stop() to avoid warning on not being able to stop
secondary CPUs during panic
- perf: enable the ARM Statistical Profiling Extensions (SPE) on ACPI
platforms
- perf: DDR performance monitor support for iMX8QXP
- cache_line_size() can now be set from DT or ACPI/PPTT if provided to
cope with a system cache info not exposed via the CPUID registers
- Avoid warning on hardware cache line size greater than
ARCH_DMA_MINALIGN if the system is fully coherent
- arm64 do_page_fault() and hugetlb cleanups
- Refactor set_pte_at() to avoid redundant READ_ONCE(*ptep)
- Ignore ACPI 5.1 FADTs reported as 5.0 (infer from the 'arm_boot_flags'
introduced in 5.1)
- CONFIG_RANDOMIZE_BASE now enabled in defconfig
- Allow the selection of ARM64_MODULE_PLTS, currently only done via
RANDOMIZE_BASE (and an erratum workaround), allowing modules to spill
over into the vmalloc area
- Make ZONE_DMA32 configurable
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas:
- arm64 support for syscall emulation via PTRACE_SYSEMU{,_SINGLESTEP}
- Wire up VM_FLUSH_RESET_PERMS for arm64, allowing the core code to
manage the permissions of executable vmalloc regions more strictly
- Slight performance improvement by keeping softirqs enabled while
touching the FPSIMD/SVE state (kernel_neon_begin/end)
- Expose a couple of ARMv8.5 features to user (HWCAP): CondM (new
XAFLAG and AXFLAG instructions for floating point comparison flags
manipulation) and FRINT (rounding floating point numbers to integers)
- Re-instate ARM64_PSEUDO_NMI support which was previously marked as
BROKEN due to some bugs (now fixed)
- Improve parking of stopped CPUs and implement an arm64-specific
panic_smp_self_stop() to avoid warning on not being able to stop
secondary CPUs during panic
- perf: enable the ARM Statistical Profiling Extensions (SPE) on ACPI
platforms
- perf: DDR performance monitor support for iMX8QXP
- cache_line_size() can now be set from DT or ACPI/PPTT if provided to
cope with a system cache info not exposed via the CPUID registers
- Avoid warning on hardware cache line size greater than
ARCH_DMA_MINALIGN if the system is fully coherent
- arm64 do_page_fault() and hugetlb cleanups
- Refactor set_pte_at() to avoid redundant READ_ONCE(*ptep)
- Ignore ACPI 5.1 FADTs reported as 5.0 (infer from the
'arm_boot_flags' introduced in 5.1)
- CONFIG_RANDOMIZE_BASE now enabled in defconfig
- Allow the selection of ARM64_MODULE_PLTS, currently only done via
RANDOMIZE_BASE (and an erratum workaround), allowing modules to spill
over into the vmalloc area
- Make ZONE_DMA32 configurable
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (54 commits)
perf: arm_spe: Enable ACPI/Platform automatic module loading
arm_pmu: acpi: spe: Add initial MADT/SPE probing
ACPI/PPTT: Add function to return ACPI 6.3 Identical tokens
ACPI/PPTT: Modify node flag detection to find last IDENTICAL
x86/entry: Simplify _TIF_SYSCALL_EMU handling
arm64: rename dump_instr as dump_kernel_instr
arm64/mm: Drop [PTE|PMD]_TYPE_FAULT
arm64: Implement panic_smp_self_stop()
arm64: Improve parking of stopped CPUs
arm64: Expose FRINT capabilities to userspace
arm64: Expose ARMv8.5 CondM capability to userspace
arm64: defconfig: enable CONFIG_RANDOMIZE_BASE
arm64: ARM64_MODULES_PLTS must depend on MODULES
arm64: bpf: do not allocate executable memory
arm64/kprobes: set VM_FLUSH_RESET_PERMS on kprobe instruction pages
arm64/mm: wire up CONFIG_ARCH_HAS_SET_DIRECT_MAP
arm64: module: create module allocations without exec permissions
arm64: Allow user selection of ARM64_MODULE_PLTS
acpi/arm64: ignore 5.1 FADTs that are reported as 5.0
arm64: Allow selecting Pseudo-NMI again
...
swap_readpage() sets waiter = bio->bi_private even if synchronous = F,
this means that the caller can get the spurious wakeup after return.
This can be fatal if blk_wake_io_task() does
set_current_state(TASK_RUNNING) after the caller does
set_special_state(), in the worst case the kernel can crash in
do_task_dead().
Link: http://lkml.kernel.org/r/20190704160301.GA5956@redhat.com
Fixes: 0619317ff8 ("block: add polled wakeup task helper")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Qian Cai <cai@lca.pw>
Acked-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In production we have noticed hard lockups on large machines running
large jobs due to kswaps hoarding lru lock within isolate_lru_pages when
sc->reclaim_idx is 0 which is a small zone. The lru was couple hundred
GiBs and the condition (page_zonenum(page) > sc->reclaim_idx) in
isolate_lru_pages() was basically skipping GiBs of pages while holding
the LRU spinlock with interrupt disabled.
On further inspection, it seems like there are two issues:
(1) If kswapd on the return from balance_pgdat() could not sleep (i.e.
node is still unbalanced), the classzone_idx is unintentionally set
to 0 and the whole reclaim cycle of kswapd will try to reclaim only
the lowest and smallest zone while traversing the whole memory.
(2) Fundamentally isolate_lru_pages() is really bad when the
allocation has woken kswapd for a smaller zone on a very large machine
running very large jobs. It can hoard the LRU spinlock while skipping
over 100s of GiBs of pages.
This patch only fixes (1). (2) needs a more fundamental solution. To
fix (1), in the kswapd context, if pgdat->kswapd_classzone_idx is
invalid use the classzone_idx of the previous kswapd loop otherwise use
the one the waker has requested.
Link: http://lkml.kernel.org/r/20190701201847.251028-1-shakeelb@google.com
Fixes: e716f2eb24 ("mm, vmscan: prevent kswapd sleeping prematurely due to mismatched classzone_idx")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 0e56acae4b ("mm: initialize MAX_ORDER_NR_PAGES at a time
instead of doing larger sections") is causing a regression on some
systems when the kernel is booted as Xen dom0.
The system will just hang in early boot.
Reason is an endless loop in get_page_from_freelist() in case the first
zone looked at has no free memory. deferred_grow_zone() is always
returning true due to the following code snipplet:
/* If the zone is empty somebody else may have cleared out the zone */
if (!deferred_init_mem_pfn_range_in_zone(&i, zone, &spfn, &epfn,
first_deferred_pfn)) {
pgdat->first_deferred_pfn = ULONG_MAX;
pgdat_resize_unlock(pgdat, &flags);
return true;
}
This in turn results in the loop as get_page_from_freelist() is assuming
forward progress can be made by doing some more struct page
initialization.
Link: http://lkml.kernel.org/r/20190620160821.4210-1-jgross@suse.com
Fixes: 0e56acae4b ("mm: initialize MAX_ORDER_NR_PAGES at a time instead of doing larger sections")
Signed-off-by: Juergen Gross <jgross@suse.com>
Suggested-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Acked-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
No point having two call sites (earlier in init_rootfs() from
mnt_init() in case we are going to use shmem-style rootfs,
later from do_basic_setup() unconditionally), along with the
logics in shmem_init() itself to make the second call a no-op...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
pcpu_setup_first_chunk() will panic or BUG_ON if the are some
error and doesn't return any error, hence it can be defined to
return void.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
[Dennis: fixed kbuild warning for pcpu_page_first_chunk()]
Christoph Hellwig says:
====================
Below is a series that cleans up the dev_pagemap interface so that it is
more easily usable, which removes the need to wrap it in hmm and thus
allowing to kill a lot of code
Changes since v3:
- pull in "mm/swap: Fix release_pages() when releasing devmap pages" and
rebase the other patches on top of that
- fold the hmm_devmem_add_resource into the DEVICE_PUBLIC memory removal
patch
- remove _vm_normal_page as it isn't needed without DEVICE_PUBLIC memory
- pick up various ACKs
Changes since v2:
- fix nvdimm kunit build
- add a new memory type for device dax
- fix a few issues in intermediate patches that didn't show up in the end
result
- incorporate feedback from Michal Hocko, including killing of
the DEVICE_PUBLIC memory type entirely
Changes since v1:
- rebase
- also switch p2pdma to the internal refcount
- add type checking for pgmap->type
- rename the migrate method to migrate_to_ram
- cleanup the altmap_valid flag
- various tidbits from the reviews
====================
Conflicts resolved by:
- Keeping Ira's version of the code in swap.c
- Using the delete for the section in hmm.rst
- Using the delete for the devmap code in hmm.c and .h
* branch 'hmm-devmem-cleanup.4': (24 commits)
mm: don't select MIGRATE_VMA_HELPER from HMM_MIRROR
mm: remove the HMM config option
mm: sort out the DEVICE_PRIVATE Kconfig mess
mm: simplify ZONE_DEVICE page private data
mm: remove hmm_devmem_add
mm: remove hmm_vma_alloc_locked_page
nouveau: use devm_memremap_pages directly
nouveau: use alloc_page_vma directly
PCI/P2PDMA: use the dev_pagemap internal refcount
device-dax: use the dev_pagemap internal refcount
memremap: provide an optional internal refcount in struct dev_pagemap
memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag
memremap: remove the data field in struct dev_pagemap
memremap: add a migrate_to_ram method to struct dev_pagemap_ops
memremap: lift the devmap_enable manipulation into devm_memremap_pages
memremap: pass a struct dev_pagemap to ->kill and ->cleanup
memremap: move dev_pagemap callbacks into a separate structure
memremap: validate the pagemap type passed to devm_memremap_pages
mm: factor out a devm_request_free_mem_region helper
mm: export alloc_pages_vma
...
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
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Merge tag 'v5.2-rc7' into rdma.git hmm
Required for dependencies in the next patches.
The migrate_vma helper is only used by noveau to migrate device private
pages around. Other HMM_MIRROR users like amdgpu or infiniband don't
need it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
All the mm/hmm.c code is better keyed off HMM_MIRROR. Also let nouveau
depend on it instead of the mix of a dummy dependency symbol plus the
actually selected one. Drop various odd dependencies, as the code is
pretty portable.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
The ZONE_DEVICE support doesn't depend on anything HMM related, just on
various bits of arch support as indicated by the architecture. Also
don't select the option from nouveau as it isn't present in many setups,
and depend on it instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Remove the clumsy hmm_devmem_page_{get,set}_drvdata helpers, and
instead just access the page directly. Also make the page data
a void pointer, and thus much easier to use.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
There isn't really much value add in the hmm_devmem_add wrapper and
more, as using devm_memremap_pages directly now is just as simple.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
The only user of it has just been removed, and there wasn't really any need
to wrap a basic memory allocator to start with.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Add a flags field to struct dev_pagemap to replace the altmap_valid
boolean to be a little more extensible. Also add a pgmap_altmap() helper
to find the optional altmap and clean up the code using the altmap using
it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
struct dev_pagemap is always embedded into a containing structure, so
there is no need to an additional private data field.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This replaces the hacky ->fault callback, which is currently directly
called from common code through a hmm specific data structure as an
exercise in layering violations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Just check if there is a ->page_free operation set and take care of the
static key enable, as well as the put using device managed resources.
Also check that a ->page_free is provided for the pgmaps types that
require it, and check for a valid type as well while we are at it.
Note that this also fixes the fact that hmm never called
dev_pagemap_put_ops and thus would leave the slow path enabled forever,
even after a device driver unload or disable.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Passing the actual typed structure leads to more understandable code
vs just passing the ref member.
Reported-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
The dev_pagemap is a growing too many callbacks. Move them into a
separate ops structure so that they are not duplicated for multiple
instances, and an attacker can't easily overwrite them.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Keep the physical address allocation that hmm_add_device does with the
rest of the resource code, and allow future reuse of it without the hmm
wrapper.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
nouveau is currently using this through an odd hmm wrapper, and I plan
to switch it to the real thing later in this series.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
->mapping isn't even used by HMM users, and the field at the same offset
in the zone_device part of the union is declared as pad. (Which btw is
rather confusing, as DAX uses ->pgmap and ->mapping from two different
sides of the union, but DAX doesn't use hmm_devmem_free).
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
The code hasn't been used since it was added to the tree, and doesn't
appear to actually be usable.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This code is a trivial wrapper around device model helpers, which
should have been integrated into the driver device model usage from
the start. Assuming it actually had users, which it never had since
the code was added more than 1 1/2 years ago.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
release_pages() is an optimized version of a loop around put_page().
Unfortunately for devmap pages the logic is not entirely correct in
release_pages(). This is because device pages can be more than type
MEMORY_DEVICE_PUBLIC. There are in fact 4 types, private, public, FS DAX,
and PCI P2PDMA. Some of these have specific needs to "put" the page while
others do not.
This logic to handle any special needs is contained in
put_devmap_managed_page(). Therefore all devmap pages should be processed
by this function where we can contain the correct logic for a page put.
Handle all device type pages within release_pages() by calling
put_devmap_managed_page() on all devmap pages. If
put_devmap_managed_page() returns true the page has been put and we
continue with the next page. A false return of put_devmap_managed_page()
means the page did not require special processing and should fall to
"normal" processing.
This was found via code inspection while determining if release_pages()
and the new put_user_pages() could be interchangeable.[1]
[1] https://lkml.kernel.org/r/20190523172852.GA27175@iweiny-DESK2.sc.intel.com
Link: https://lkml.kernel.org/r/20190605214922.17684-1-ira.weiny@intel.com
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
0-Day test system reported some OOM regressions for several THP
(Transparent Huge Page) swap test cases. These regressions are bisected
to 6861428921 ("block: always define BIO_MAX_PAGES as 256"). In the
commit, BIO_MAX_PAGES is set to 256 even when THP swap is enabled. So the
bio_alloc(gfp_flags, 512) in get_swap_bio() may fail when swapping out
THP. That causes the OOM.
As in the patch description of 6861428921 ("block: always define
BIO_MAX_PAGES as 256"), THP swap should use multi-page bvec to write THP
to swap space. So the issue is fixed via doing that in get_swap_bio().
BTW: I remember I have checked the THP swap code when 6861428921
("block: always define BIO_MAX_PAGES as 256") was merged, and thought the
THP swap code needn't to be changed. But apparently, I was wrong. I
should have done this at that time.
Link: http://lkml.kernel.org/r/20190624075515.31040-1-ying.huang@intel.com
Fixes: 6861428921 ("block: always define BIO_MAX_PAGES as 256")
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
gcc gets confused in pcpu_get_vm_areas() because there are too many
branches that affect whether 'lva' was initialized before it gets used:
mm/vmalloc.c: In function 'pcpu_get_vm_areas':
mm/vmalloc.c:991:4: error: 'lva' may be used uninitialized in this function [-Werror=maybe-uninitialized]
insert_vmap_area_augment(lva, &va->rb_node,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
&free_vmap_area_root, &free_vmap_area_list);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/vmalloc.c:916:20: note: 'lva' was declared here
struct vmap_area *lva;
^~~
Add an intialization to NULL, and check whether this has changed before
the first use.
[akpm@linux-foundation.org: tweak comments]
Link: http://lkml.kernel.org/r/20190618092650.2943749-1-arnd@arndb.de
Fixes: 68ad4a3304 ("mm/vmalloc.c: keep track of free blocks for vmap allocation")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Joel Fernandes <joelaf@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In dump_oom_summary() oc->constraint is used to show oom_constraint_text,
but it hasn't been set before. So the value of it is always the default
value 0. We should inititialize it before.
Bellow is the output when memcg oom occurs,
before this patch:
oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null), cpuset=/,mems_allowed=0,oom_memcg=/foo,task_memcg=/foo,task=bash,pid=7997,uid=0
after this patch:
oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null), cpuset=/,mems_allowed=0,oom_memcg=/foo,task_memcg=/foo,task=bash,pid=13681,uid=0
Link: http://lkml.kernel.org/r/1560522038-15879-1-git-send-email-laoar.shao@gmail.com
Fixes: ef8444ea01 ("mm, oom: reorganize the oom report in dump_header")
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Wind Yu <yuzhoujian@didichuxing.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
madvise(MADV_SOFT_OFFLINE) often returns -EBUSY when calling soft offline
for hugepages with overcommitting enabled. That was caused by the
suboptimal code in current soft-offline code. See the following part:
ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL,
MIGRATE_SYNC, MR_MEMORY_FAILURE);
if (ret) {
...
} else {
/*
* We set PG_hwpoison only when the migration source hugepage
* was successfully dissolved, because otherwise hwpoisoned
* hugepage remains on free hugepage list, then userspace will
* find it as SIGBUS by allocation failure. That's not expected
* in soft-offlining.
*/
ret = dissolve_free_huge_page(page);
if (!ret) {
if (set_hwpoison_free_buddy_page(page))
num_poisoned_pages_inc();
}
}
return ret;
Here dissolve_free_huge_page() returns -EBUSY if the migration source page
was freed into buddy in migrate_pages(), but even in that case we actually
has a chance that set_hwpoison_free_buddy_page() succeeds. So that means
current code gives up offlining too early now.
dissolve_free_huge_page() checks that a given hugepage is suitable for
dissolving, where we should return success for !PageHuge() case because
the given hugepage is considered as already dissolved.
This change also affects other callers of dissolve_free_huge_page(), which
are cleaned up together.
[n-horiguchi@ah.jp.nec.com: v3]
Link: http://lkml.kernel.org/r/1560761476-4651-3-git-send-email-n-horiguchi@ah.jp.nec.comLink: http://lkml.kernel.org/r/1560154686-18497-3-git-send-email-n-horiguchi@ah.jp.nec.com
Fixes: 6bc9b56433 ("mm: fix race on soft-offlining")
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reported-by: Chen, Jerry T <jerry.t.chen@intel.com>
Tested-by: Chen, Jerry T <jerry.t.chen@intel.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Xishi Qiu <xishi.qiuxishi@alibaba-inc.com>
Cc: "Chen, Jerry T" <jerry.t.chen@intel.com>
Cc: "Zhuo, Qiuxu" <qiuxu.zhuo@intel.com>
Cc: <stable@vger.kernel.org> [4.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The pass/fail of soft offline should be judged by checking whether the
raw error page was finally contained or not (i.e. the result of
set_hwpoison_free_buddy_page()), but current code do not work like
that. It might lead us to misjudge the test result when
set_hwpoison_free_buddy_page() fails.
Without this fix, there are cases where madvise(MADV_SOFT_OFFLINE) may
not offline the original page and will not return an error.
Link: http://lkml.kernel.org/r/1560154686-18497-2-git-send-email-n-horiguchi@ah.jp.nec.com
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Fixes: 6bc9b56433 ("mm: fix race on soft-offlining")
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Xishi Qiu <xishi.qiuxishi@alibaba-inc.com>
Cc: "Chen, Jerry T" <jerry.t.chen@intel.com>
Cc: "Zhuo, Qiuxu" <qiuxu.zhuo@intel.com>
Cc: <stable@vger.kernel.org> [4.19+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mpol_rebind_nodemask() is called for MPOL_BIND and MPOL_INTERLEAVE
mempoclicies when the tasks's cpuset's mems_allowed changes. For
policies created without MPOL_F_STATIC_NODES or MPOL_F_RELATIVE_NODES,
it works by remapping the policy's allowed nodes (stored in v.nodes)
using the previous value of mems_allowed (stored in
w.cpuset_mems_allowed) as the domain of map and the new mems_allowed
(passed as nodes) as the range of the map (see the comment of
bitmap_remap() for details).
The result of remapping is stored back as policy's nodemask in v.nodes,
and the new value of mems_allowed should be stored in
w.cpuset_mems_allowed to facilitate the next rebind, if it happens.
However, 213980c0f2 ("mm, mempolicy: simplify rebinding mempolicies
when updating cpusets") introduced a bug where the result of remapping
is stored in w.cpuset_mems_allowed instead. Thus, a mempolicy's
allowed nodes can evolve in an unexpected way after a series of
rebinding due to cpuset mems_allowed changes, possibly binding to a
wrong node or a smaller number of nodes which may e.g. overload them.
This patch fixes the bug so rebinding again works as intended.
[vbabka@suse.cz: new changlog]
Link: http://lkml.kernel.org/r/ef6a69c6-c052-b067-8f2c-9d615c619bb9@suse.cz
Link: http://lkml.kernel.org/r/1558768043-23184-1-git-send-email-zhongjiang@huawei.com
Fixes: 213980c0f2 ("mm, mempolicy: simplify rebinding mempolicies when updating cpusets")
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the trylock on the hmm->mirrors_sem fails the function will return
without decrementing the notifiers that were previously incremented. Since
the caller will not call invalidate_range_end() on EAGAIN this will result
in notifiers becoming permanently incremented and deadlock.
If the sync_cpu_device_pagetables() required blocking the function will
not return EAGAIN even though the device continues to touch the
pages. This is a violation of the mmu notifier contract.
Switch, and rename, the ranges_lock to a spin lock so we can reliably
obtain it without blocking during error unwind.
The error unwind is necessary since the notifiers count must be held
incremented across the call to sync_cpu_device_pagetables() as we cannot
allow the range to become marked valid by a parallel
invalidate_start/end() pair while doing sync_cpu_device_pagetables().
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Philip Yang <Philip.Yang@amd.com>
hmm_release() is called exactly once per hmm. ops->release() cannot
accidentally trigger any action that would recurse back onto
hmm->mirrors_sem.
This fixes a use after-free race of the form:
CPU0 CPU1
hmm_release()
up_write(&hmm->mirrors_sem);
hmm_mirror_unregister(mirror)
down_write(&hmm->mirrors_sem);
up_write(&hmm->mirrors_sem);
kfree(mirror)
mirror->ops->release(mirror)
The only user we have today for ops->release is an empty function, so this
is unambiguously safe.
As a consequence of plugging this race drivers are not allowed to
register/unregister mirrors from within a release op.
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Philip Yang <Philip.Yang@amd.com>
Trying to misuse a range outside its lifetime is a kernel bug. Use poison
bytes to help detect this condition. Double unregister will reliably crash.
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Acked-by: Souptick Joarder <jrdr.linux@gmail.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Tested-by: Philip Yang <Philip.Yang@amd.com>
No other register/unregister kernel API attempts to provide this kind of
protection as it is inherently racy, so just drop it.
Callers should provide their own protection, and it appears nouveau
already does.
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Jérôme Glisse <jglisse@redhat.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Philip Yang <Philip.Yang@amd.com>
Wire up the special helper functions to manipulate aliases of vmalloc
regions in the linear map.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
In the spirit of filemap_fdatawait_range() and
filemap_fdatawait_keep_errors(), introduce
filemap_fdatawait_range_keep_errors() which both takes a range upon
which to wait and does not clear errors from the address space.
Signed-off-by: Ross Zwisler <zwisler@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org
