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95f9ab2d59
12807 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Johannes Weiner
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95f9ab2d59 |
mm: workingset: don't drop refault information prematurely
Patch series "psi: pressure stall information for CPU, memory, and IO", v4. Overview PSI reports the overall wallclock time in which the tasks in a system (or cgroup) wait for (contended) hardware resources. This helps users understand the resource pressure their workloads are under, which allows them to rootcause and fix throughput and latency problems caused by overcommitting, underprovisioning, suboptimal job placement in a grid; as well as anticipate major disruptions like OOM. Real-world applications We're using the data collected by PSI (and its previous incarnation, memdelay) quite extensively at Facebook, and with several success stories. One usecase is avoiding OOM hangs/livelocks. The reason these happen is because the OOM killer is triggered by reclaim not being able to free pages, but with fast flash devices there is *always* some clean and uptodate cache to reclaim; the OOM killer never kicks in, even as tasks spend 90% of the time thrashing the cache pages of their own executables. There is no situation where this ever makes sense in practice. We wrote a <100 line POC python script to monitor memory pressure and kill stuff way before such pathological thrashing leads to full system losses that would require forcible hard resets. We've since extended and deployed this code into other places to guarantee latency and throughput SLAs, since they're usually violated way before the kernel OOM killer would ever kick in. It is available here: https://github.com/facebookincubator/oomd Eventually we probably want to trigger the in-kernel OOM killer based on extreme sustained pressure as well, so that Linux can avoid memory livelocks - which technically aren't deadlocks, but to the user indistinguishable from them - out of the box. We'd continue using OOMD as the first line of defense to ensure workload health and implement complex kill policies that are beyond the scope of the kernel. We also use PSI memory pressure for loadshedding. Our batch job infrastructure used to use heuristics based on various VM stats to anticipate OOM situations, with lackluster success. We switched it to PSI and managed to anticipate and avoid OOM kills and lockups fairly reliably. The reduction of OOM outages in the worker pool raised the pool's aggregate productivity, and we were able to switch that service to smaller machines. Lastly, we use cgroups to isolate a machine's main workload from maintenance crap like package upgrades, logging, configuration, as well as to prevent multiple workloads on a machine from stepping on each others' toes. We were not able to configure this properly without the pressure metrics; we would see latency or bandwidth drops, but it would often be hard to impossible to rootcause it post-mortem. We now log and graph pressure for the containers in our fleet and can trivially link latency spikes and throughput drops to shortages of specific resources after the fact, and fix the job config/scheduling. PSI has also received testing, feedback, and feature requests from Android and EndlessOS for the purpose of low-latency OOM killing, to intervene in pressure situations before the UI starts hanging. How do you use this feature? A kernel with CONFIG_PSI=y will create a /proc/pressure directory with 3 files: cpu, memory, and io. If using cgroup2, cgroups will also have cpu.pressure, memory.pressure and io.pressure files, which simply aggregate task stalls at the cgroup level instead of system-wide. The cpu file contains one line: some avg10=2.04 avg60=0.75 avg300=0.40 total=157656722 The averages give the percentage of walltime in which one or more tasks are delayed on the runqueue while another task has the CPU. They're recent averages over 10s, 1m, 5m windows, so you can tell short term trends from long term ones, similarly to the load average. The total= value gives the absolute stall time in microseconds. This allows detecting latency spikes that might be too short to sway the running averages. It also allows custom time averaging in case the 10s/1m/5m windows aren't adequate for the usecase (or are too coarse with future hardware). What to make of this "some" metric? If CPU utilization is at 100% and CPU pressure is 0, it means the system is perfectly utilized, with one runnable thread per CPU and nobody waiting. At two or more runnable tasks per CPU, the system is 100% overcommitted and the pressure average will indicate as much. From a utilization perspective this is a great state of course: no CPU cycles are being wasted, even when 50% of the threads were to go idle (as most workloads do vary). From the perspective of the individual job it's not great, however, and they would do better with more resources. Depending on what your priority and options are, raised "some" numbers may or may not require action. The memory file contains two lines: some avg10=70.24 avg60=68.52 avg300=69.91 total=3559632828 full avg10=57.59 avg60=58.06 avg300=60.38 total=3300487258 The some line is the same as for cpu, the time in which at least one task is stalled on the resource. In the case of memory, this includes waiting on swap-in, page cache refaults and page reclaim. The full line, however, indicates time in which *nobody* is using the CPU productively due to pressure: all non-idle tasks are waiting for memory in one form or another. Significant time spent in there is a good trigger for killing things, moving jobs to other machines, or dropping incoming requests, since neither the jobs nor the machine overall are making too much headway. The io file is similar to memory. Because the block layer doesn't have a concept of hardware contention right now (how much longer is my IO request taking due to other tasks?), it reports CPU potential lost on all IO delays, not just the potential lost due to competition. FAQ Q: How is PSI's CPU component different from the load average? A: There are several quirks in the load average that make it hard to impossible to tell how overcommitted the CPU really is. 1. The load average is reported as a raw number of active tasks. You need to know how many CPUs there are in the system, how many CPUs the workload is allowed to use, then think about what the proportion between load and the number of CPUs mean for the tasks trying to run. PSI reports the percentage of wallclock time in which tasks are waiting for a CPU to run on. It doesn't matter how many CPUs are present or usable. The number always tells the quality of life of tasks in the system or in a particular cgroup. 2. The shortest averaging window is 1m, which is extremely coarse, and it's sampled in 5s intervals. A *lot* can happen on a CPU in 5 seconds. This *may* be able to identify persistent long-term trends and very clear and obvious overloads, but it's unusable for latency spikes and more subtle overutilization. PSI's shortest window is 10s. It also exports the cumulative stall times (in microseconds) of synchronously recorded events. 3. On Linux, the load average for historical reasons includes all TASK_UNINTERRUPTIBLE tasks. This gives a broader sense of how busy the system is, but on the flipside it doesn't distinguish whether tasks are likely to contend over the CPU or IO - which obviously requires very different interventions from a sys admin or a job scheduler. PSI reports independent metrics for CPU and IO. You can tell which resource is making the tasks wait, but in conjunction still see how overloaded the system is overall. Q: What's the cost / performance impact of this feature? A: PSI's primary cost is in the scheduler, in particular task wakeups and sleeps. I benchmarked this code using Facebook's two most scheduling sensitive workloads: memcache and webserver. They handle a ton of small requests - lots of wakeups and sleeps with little actual work in between - so they tend to be canaries for scheduler regressions. In the tests, the boxes were handling live traffic over the course of several hours. Half the machines, the control, ran with CONFIG_PSI=n. For memcache I used eight machines total. They're 2-socket, 14 core, 56 thread boxes. The test runs for half the test period, flips the test and control kernels on the hardware to rule out HW factors, DC location etc., then runs the other half of the test. For the webservers, I used 32 machines total. They're single socket, 16 core, 32 thread machines. During the memcache test, CPU load was nopsi=78.05% psi=78.98% in the first half and nopsi=77.52% psi=78.25%, so PSI added between 0.7 and 0.9 percentage points to the CPU load, a difference of about 1%. UPDATE: I re-ran this test with the v3 version of this patch set and the CPU utilization was equivalent between test and control. UPDATE: v4 is on par with v3. As far as end-to-end request latency from the client perspective goes, we don't sample those finely enough to capture the requests going to those particular machines during the test, but we know the p50 turnaround time in this workload is 54us, and perf bench sched pipe on those machines show nopsi=5.232666 us/op and psi=5.587347 us/op, so this doesn't add much here either. The profile for the pipe benchmark shows: 0.87% sched-pipe [kernel.vmlinux] [k] psi_group_change 0.83% perf.real [kernel.vmlinux] [k] psi_group_change 0.82% perf.real [kernel.vmlinux] [k] psi_task_change 0.58% sched-pipe [kernel.vmlinux] [k] psi_task_change The webserver load is running inside 4 nested cgroup levels. The CPU load with both nopsi and psi kernels was indistinguishable at 81%. For comparison, we had to disable the cgroup cpu controller on the webservers because it added 4 percentage points to the CPU% during this same exact test. Versions of this accounting code now run on 80% of our fleet. None of our workloads have reported regressions during the rollout. Daniel Drake said: : I just retested the latest version at : http://git.cmpxchg.org/cgit.cgi/linux-psi.git (Linux 4.18) and the results : are great. : : Test setup: : Endless OS : GeminiLake N4200 low end laptop : 2GB RAM : swap (and zram swap) disabled : : Baseline test: open a handful of large-ish apps and several website : tabs in Google Chrome. : : Results: after a couple of minutes, system is excessively thrashing, mouse : cursor can barely be moved, UI is not responding to mouse clicks, so it's : impractical to recover from this situation as an ordinary user : : Add my simple killer: : https://gist.github.com/dsd/a8988bf0b81a6163475988120fe8d9cd : : Results: when the thrashing causes the UI to become sluggish, the killer : steps in and kills something (usually a chrome tab), and the system : remains usable. I repeatedly opened more apps and more websites over a 15 : minute period but I wasn't able to get the system to a point of UI : unresponsiveness. Suren said: : Backported to 4.9 and retested on ARMv8 8 code system running Android. : Signals behave as expected reacting to memory pressure, no jumps in : "total" counters that would indicate an overflow/underflow issues. Nicely : done! This patch (of 9): If we keep just enough refault information to match the *current* page cache during reclaim time, we could lose a lot of events when there is only a temporary spike in non-cache memory consumption that pushes out all the cache. Once cache comes back, we won't see those refaults. They might not be actionable for LRU aging, but we want to know about them for measuring memory pressure. [hannes@cmpxchg.org: switch to NUMA-aware lru and slab counters] Link: http://lkml.kernel.org/r/20181009184732.762-2-hannes@cmpxchg.org Link: http://lkml.kernel.org/r/20180828172258.3185-2-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <jweiner@fb.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Rik van Riel <riel@surriel.com> Tested-by: Daniel Drake <drake@endlessm.com> Tested-by: Suren Baghdasaryan <surenb@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: Christopher Lameter <cl@linux.com> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
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f0d7787414 |
mm, slab: shorten kmalloc cache names for large sizes
Kmalloc cache names can get quite long for large object sizes, when the sizes are expressed in bytes. Use 'k' and 'M' prefixes to make the names as short as possible e.g. in /proc/slabinfo. This works, as we mostly use power-of-two sizes, with exceptions only below 1k. Example: 'kmalloc-4194304' becomes 'kmalloc-4M' Link: http://lkml.kernel.org/r/20180731090649.16028-7-vbabka@suse.cz Suggested-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: Roman Gushchin <guro@fb.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Vijayanand Jitta <vjitta@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vlastimil Babka
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b29940c1ab |
mm: rename and change semantics of nr_indirectly_reclaimable_bytes
The vmstat counter NR_INDIRECTLY_RECLAIMABLE_BYTES was introduced by
commit
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Vlastimil Babka
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1291523f2c |
mm, slab/slub: introduce kmalloc-reclaimable caches
Kmem caches can be created with a SLAB_RECLAIM_ACCOUNT flag, which
indicates they contain objects which can be reclaimed under memory
pressure (typically through a shrinker). This makes the slab pages
accounted as NR_SLAB_RECLAIMABLE in vmstat, which is reflected also the
MemAvailable meminfo counter and in overcommit decisions. The slab pages
are also allocated with __GFP_RECLAIMABLE, which is good for
anti-fragmentation through grouping pages by mobility.
The generic kmalloc-X caches are created without this flag, but sometimes
are used also for objects that can be reclaimed, which due to varying size
cannot have a dedicated kmem cache with SLAB_RECLAIM_ACCOUNT flag. A
prominent example are dcache external names, which prompted the creation
of a new, manually managed vmstat counter NR_INDIRECTLY_RECLAIMABLE_BYTES
in commit
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Vlastimil Babka
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cc252eae85 |
mm, slab: combine kmalloc_caches and kmalloc_dma_caches
Patch series "kmalloc-reclaimable caches", v4. As discussed at LSF/MM [1] here's a patchset that introduces kmalloc-reclaimable caches (more details in the second patch) and uses them for dcache external names. That allows us to repurpose the NR_INDIRECTLY_RECLAIMABLE_BYTES counter later in the series. With patch 3/6, dcache external names are allocated from kmalloc-rcl-* caches, eliminating the need for manual accounting. More importantly, it also ensures the reclaimable kmalloc allocations are grouped in pages separate from the regular kmalloc allocations. The need for proper accounting of dcache external names has shown it's easy for misbehaving process to allocate lots of them, causing premature OOMs. Without the added grouping, it's likely that a similar workload can interleave the dcache external names allocations with regular kmalloc allocations (note: I haven't searched myself for an example of such regular kmalloc allocation, but I would be very surprised if there wasn't some). A pathological case would be e.g. one 64byte regular allocations with 63 external dcache names in a page (64x64=4096), which means the page is not freed even after reclaiming after all dcache names, and the process can thus "steal" the whole page with single 64byte allocation. If other kmalloc users similar to dcache external names become identified, they can also benefit from the new functionality simply by adding __GFP_RECLAIMABLE to the kmalloc calls. Side benefits of the patchset (that could be also merged separately) include removed branch for detecting __GFP_DMA kmalloc(), and shortening kmalloc cache names in /proc/slabinfo output. The latter is potentially an ABI break in case there are tools parsing the names and expecting the values to be in bytes. This is how /proc/slabinfo looks like after booting in virtme: ... kmalloc-rcl-4M 0 0 4194304 1 1024 : tunables 1 1 0 : slabdata 0 0 0 ... kmalloc-rcl-96 7 32 128 32 1 : tunables 120 60 8 : slabdata 1 1 0 kmalloc-rcl-64 25 128 64 64 1 : tunables 120 60 8 : slabdata 2 2 0 kmalloc-rcl-32 0 0 32 124 1 : tunables 120 60 8 : slabdata 0 0 0 kmalloc-4M 0 0 4194304 1 1024 : tunables 1 1 0 : slabdata 0 0 0 kmalloc-2M 0 0 2097152 1 512 : tunables 1 1 0 : slabdata 0 0 0 kmalloc-1M 0 0 1048576 1 256 : tunables 1 1 0 : slabdata 0 0 0 ... /proc/vmstat with renamed nr_indirectly_reclaimable_bytes counter: ... nr_slab_reclaimable 2817 nr_slab_unreclaimable 1781 ... nr_kernel_misc_reclaimable 0 ... /proc/meminfo with new KReclaimable counter: ... Shmem: 564 kB KReclaimable: 11260 kB Slab: 18368 kB SReclaimable: 11260 kB SUnreclaim: 7108 kB KernelStack: 1248 kB ... This patch (of 6): The kmalloc caches currently mainain separate (optional) array kmalloc_dma_caches for __GFP_DMA allocations. There are tests for __GFP_DMA in the allocation hotpaths. We can avoid the branches by combining kmalloc_caches and kmalloc_dma_caches into a single two-dimensional array where the outer dimension is cache "type". This will also allow to add kmalloc-reclaimable caches as a third type. Link: http://lkml.kernel.org/r/20180731090649.16028-2-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: Roman Gushchin <guro@fb.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Laura Abbott <labbott@redhat.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Vijayanand Jitta <vjitta@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Andrea Arcangeli
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3b9aadf727 |
userfaultfd: allow get_mempolicy(MPOL_F_NODE|MPOL_F_ADDR) to trigger userfaults
get_mempolicy(MPOL_F_NODE|MPOL_F_ADDR) called a get_user_pages that would
not be waiting for userfaults before failing and it would hit on a SIGBUS
instead. Using get_user_pages_locked/unlocked instead will allow
get_mempolicy to allow userfaults to resolve the fault and fill the hole,
before grabbing the node id of the page.
If the user calls get_mempolicy() with MPOL_F_ADDR | MPOL_F_NODE for an
address inside an area managed by uffd and there is no page at that
address, the page allocation from within get_mempolicy() will fail
because get_user_pages() does not allow for page fault retry required
for uffd; the user will get SIGBUS.
With this patch, the page fault will be resolved by the uffd and the
get_mempolicy() will continue normally.
Background:
Via code review, previously the syscall would have returned -EFAULT
(vm_fault_to_errno), now it will block and wait for an userfault (if
it's waken before the fault is resolved it'll still -EFAULT).
This way get_mempolicy will give a chance to an "unaware" app to be
compliant with userfaults.
The reason this visible change is that becoming "userfault compliant"
cannot regress anything: all other syscalls including read(2)/write(2)
had to become "userfault compliant" long time ago (that's one of the
things userfaultfd can do that PROT_NONE and trapping segfaults can't).
So this is just one more syscall that become "userfault compliant" like
all other major ones already were.
This has been happening on virtio-bridge dpdk process which just called
get_mempolicy on the guest space post live migration, but before the
memory had a chance to be migrated to destination.
I didn't run an strace to be able to show the -EFAULT going away, but
I've the confirmation of the below debug aid information (only visible
with CONFIG_DEBUG_VM=y) going away with the patch:
[20116.371461] FAULT_FLAG_ALLOW_RETRY missing 0
[20116.371464] CPU: 1 PID: 13381 Comm: vhost-events Not tainted 4.17.12-200.fc28.x86_64 #1
[20116.371465] Hardware name: LENOVO 20FAS2BN0A/20FAS2BN0A, BIOS N1CET54W (1.22 ) 02/10/2017
[20116.371466] Call Trace:
[20116.371473] dump_stack+0x5c/0x80
[20116.371476] handle_userfault.cold.37+0x1b/0x22
[20116.371479] ? remove_wait_queue+0x20/0x60
[20116.371481] ? poll_freewait+0x45/0xa0
[20116.371483] ? do_sys_poll+0x31c/0x520
[20116.371485] ? radix_tree_lookup_slot+0x1e/0x50
[20116.371488] shmem_getpage_gfp+0xce7/0xe50
[20116.371491] ? page_add_file_rmap+0x1a/0x2c0
[20116.371493] shmem_fault+0x78/0x1e0
[20116.371495] ? filemap_map_pages+0x3a1/0x450
[20116.371498] __do_fault+0x1f/0xc0
[20116.371500] __handle_mm_fault+0xe2e/0x12f0
[20116.371502] handle_mm_fault+0xda/0x200
[20116.371504] __get_user_pages+0x238/0x790
[20116.371506] get_user_pages+0x3e/0x50
[20116.371510] kernel_get_mempolicy+0x40b/0x700
[20116.371512] ? vfs_write+0x170/0x1a0
[20116.371515] __x64_sys_get_mempolicy+0x21/0x30
[20116.371517] do_syscall_64+0x5b/0x160
[20116.371520] entry_SYSCALL_64_after_hwframe+0x44/0xa9
The above harmless debug message (not a kernel crash, just a
dump_stack()) is shown with CONFIG_DEBUG_VM=y to more quickly identify
and improve kernel spots that may have to become "userfaultfd
compliant" like this one (without having to run an strace and search
for syscall misbehavior). Spots like the above are more closer to a
kernel bug for the non-cooperative usages that Mike focuses on, than
for for dpdk qemu-cooperative usages that reproduced it, but it's still
nicer to get this fixed for dpdk too.
The part of the patch that caused me to think is only the
implementation issue of mpol_get, but it looks like it should work safe
no matter the kind of mempolicy structure that is (the default static
policy also starts at 1 so it'll go to 2 and back to 1 without crashing
everything at 0).
[rppt@linux.vnet.ibm.com: changelog addition]
http://lkml.kernel.org/r/20180904073718.GA26916@rapoport-lnx
Link: http://lkml.kernel.org/r/20180831214848.23676-1-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Tested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: 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>
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Matthew Wilcox
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9b5a8e00d4 |
mm: convert insert_pfn() to vm_fault_t
All callers convert its errno into a vm_fault_t, so convert it to return a vm_fault_t directly. Link: http://lkml.kernel.org/r/20180828145728.11873-11-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Souptick Joarder <jrdr.linux@gmail.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> |
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Matthew Wilcox
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79f3aa5ba9 |
mm: convert __vm_insert_mixed() to vm_fault_t
Both of its callers currently convert its errno return into a vm_fault_t, so move the conversion into __vm_insert_mixed(). Link: http://lkml.kernel.org/r/20180828145728.11873-10-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Souptick Joarder <jrdr.linux@gmail.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> |
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Matthew Wilcox
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6d958546ff |
mm: inline vm_insert_pfn_prot() into caller
vm_insert_pfn_prot() is only called from vmf_insert_pfn_prot(), so inline it and convert some of the errnos into vm_fault codes earlier. Link: http://lkml.kernel.org/r/20180828145728.11873-9-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Souptick Joarder <jrdr.linux@gmail.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> |
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Matthew Wilcox
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ae2b01f370 |
mm: remove vm_insert_pfn()
All callers are now converted to vmf_insert_pfn() so convert vmf_insert_pfn() from being a compatibility wrapper around vm_insert_pfn() to being a compatibility wrapper around vmf_insert_pfn_prot(). Link: http://lkml.kernel.org/r/20180828145728.11873-8-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Souptick Joarder <jrdr.linux@gmail.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> |
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Matthew Wilcox
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bc12e6ad96 |
mm: make vm_insert_pfn_prot() static
Now this is no longer used outside mm/memory.c, make it static. Link: http://lkml.kernel.org/r/20180828145728.11873-6-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Souptick Joarder <jrdr.linux@gmail.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> |
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Matthew Wilcox
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f5e6d1d5f8 |
mm: introduce vmf_insert_pfn_prot()
Like vm_insert_pfn_prot(), but returns a vm_fault_t instead of an errno. Also unexport vm_insert_pfn_prot as it has no modular users. Link: http://lkml.kernel.org/r/20180828145728.11873-4-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Souptick Joarder <jrdr.linux@gmail.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> |
||
|
Matthew Wilcox
|
5d74763745 |
mm: remove vm_insert_mixed()
All callers are now converted to vmf_insert_mixed() so convert vmf_insert_mixed() from being a compatibility wrapper into the real function. Link: http://lkml.kernel.org/r/20180828145728.11873-3-willy@infradead.org Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: Souptick Joarder <jrdr.linux@gmail.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> |
||
|
Souptick Joarder
|
4b96a37d1c |
mm: convert to use vm_fault_t
As part of vm_fault_t conversion filemap_page_mkwrite() for the NOMMU case was missed. Now converted. Link: http://lkml.kernel.org/r/20180828174952.GA29229@jordon-HP-15-Notebook-PC Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Oscar Salvador
|
7b0e0c0e35 |
mm/page_alloc.c: clean up check_for_memory()
check_for_memory() looks a bit confusing. First of all, we have this: if (N_MEMORY == N_NORMAL_MEMORY) return; Checking the ENUM declaration, looks like N_MEMORY canot be equal to N_NORMAL_MEMORY. I could not find where N_MEMORY is set to N_NORMAL_MEMORY, or the other way around either, so unless I am missing something, this condition will never evaluate to true. It makes sense to get rid of it. Moving forward, the operations within the loop look a bit confusing as well. We set N_HIGH_MEMORY unconditionally, and then we set N_NORMAL_MEMORY in case we have CONFIG_HIGHMEM (N_NORMAL_MEMORY != N_HIGH_MEMORY) and zone <= ZONE_NORMAL. (N_HIGH_MEMORY falls back to N_NORMAL_MEMORY on !CONFIG_HIGHMEM systems, and that is why we can just go ahead and set N_HIGH_MEMORY unconditionally) Although this works, it is a bit subtle. I think that this could be easier to follow: First, we should only set N_HIGH_MEMORY in case we have CONFIG_HIGHMEM. And then we should set N_NORMAL_MEMORY in case zone <= ZONE_NORMAL, without further checking whether we have CONFIG_HIGHMEM or not. Link: http://lkml.kernel.org/r/20180828210158.4617-1-osalvador@techadventures.net Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Michael Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Pavel Tatashin <pavel.tatashin@microsoft.com Cc: Stephen Rothwell <sfr@canb.auug.org.au> 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> |
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|
Huang Ying
|
979aafa591 |
mm/swapfile.c: clear si->swap_map[] in swap_free_cluster()
si->swap_map[] of the swap entries in cluster needs to be cleared during freeing. Previously, this is done in the caller of swap_free_cluster(). This may cause code duplication (one user now, will add more users later) and lock/unlock cluster unnecessarily. In this patch, the clearing code is moved to swap_free_cluster() to avoid the downside. Link: http://lkml.kernel.org/r/20180827075535.17406-4-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shaohua Li <shli@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Huang Ying
|
10e364da10 |
mm/swapfile.c: call free_swap_slot() in __swap_entry_free()
This is a code cleanup patch without functionality change. Originally, when __swap_entry_free() is called, and its return value is 0, free_swap_slot() will always be called to free the swap entry to the per-CPU pool. So move the call to free_swap_slot() to __swap_entry_free() to simplify the code. Link: http://lkml.kernel.org/r/20180827075535.17406-3-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shaohua Li <shli@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Huang Ying
|
bcd49e8671 |
mm/swapfile.c: use __try_to_reclaim_swap() in free_swap_and_cache()
The code path to reclaim the swap entry in free_swap_and_cache() is almost same as that of __try_to_reclaim_swap(). The largest difference is just coding style. So the support to the additional requirement of free_swap_and_cache() is added into __try_to_reclaim_swap(). free_swap_and_cache() is changed to call __try_to_reclaim_swap(), and delete the duplicated code. This will improve code readability and reduce the potential bugs. There are 2 functionality differences between __try_to_reclaim_swap() and swap entry reclaim code of free_swap_and_cache(). - free_swap_and_cache() only reclaims the swap entry if the page is unmapped or swap is getting full. The support has been added into __try_to_reclaim_swap(). - try_to_free_swap() (called by __try_to_reclaim_swap()) checks pm_suspended_storage(), while free_swap_and_cache() not. I think this is OK. Because the page and the swap entry can be reclaimed later eventually. Link: http://lkml.kernel.org/r/20180827075535.17406-2-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Shaohua Li <shli@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Vincent Whitchurch
|
154221c3e5 |
kmemleak: add module param to print warnings to dmesg
Currently, kmemleak only prints the number of suspected leaks to dmesg but requires the user to read a debugfs file to get the actual stack traces of the objects' allocation points. Add a module option to print the full object information to dmesg too. It can be enabled with kmemleak.verbose=1 on the kernel command line, or "echo 1 > /sys/module/kmemleak/parameters/verbose": This allows easier integration of kmemleak into test systems: We have automated test infrastructure to test our Linux systems. With this option, running our tests with kmemleak is as simple as enabling kmemleak and passing this command line option; the test infrastructure knows how to save kernel logs, which will now include kmemleak reports. Without this option, the test infrastructure needs to be specifically taught to read out the kmemleak debugfs file. Removing this need for special handling makes kmemleak more similar to other kernel debug options (slab debugging, debug objects, etc). Link: http://lkml.kernel.org/r/20180903144046.21023-1-vincent.whitchurch@axis.com Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> 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> |
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|
Michal Hocko
|
4e15a073a1 |
Revert "mm, mmu_notifier: annotate mmu notifiers with blockable invalidate callbacks"
Revert |
||
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Michal Hocko
|
15f570bf3d |
mm,page_alloc: PF_WQ_WORKER threads must sleep at should_reclaim_retry()
Tetsuo Handa has reported that it is possible to bypass the short sleep
for PF_WQ_WORKER threads which was introduced by commit
|
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Roman Gushchin
|
68600f623d |
mm: don't miss the last page because of round-off error
I've noticed, that dying memory cgroups are often pinned in memory by a single pagecache page. Even under moderate memory pressure they sometimes stayed in such state for a long time. That looked strange. My investigation showed that the problem is caused by applying the LRU pressure balancing math: scan = div64_u64(scan * fraction[lru], denominator), where denominator = fraction[anon] + fraction[file] + 1. Because fraction[lru] is always less than denominator, if the initial scan size is 1, the result is always 0. This means the last page is not scanned and has no chances to be reclaimed. Fix this by rounding up the result of the division. In practice this change significantly improves the speed of dying cgroups reclaim. [guro@fb.com: prevent double calculation of DIV64_U64_ROUND_UP() arguments] Link: http://lkml.kernel.org/r/20180829213311.GA13501@castle Link: http://lkml.kernel.org/r/20180827162621.30187-3-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Roman Gushchin
|
591edfb10a |
mm: drain memcg stocks on css offlining
Memcg charge is batched using per-cpu stocks, so an offline memcg can be pinned by a cached charge up to a moment, when a process belonging to some other cgroup will charge some memory on the same cpu. In other words, cached charges can prevent a memory cgroup from being reclaimed for some time, without any clear need. Let's optimize it by explicit draining of all stocks on css offlining. As draining is performed asynchronously, and is skipped if any parallel draining is happening, it's cheap. Link: http://lkml.kernel.org/r/20180827162621.30187-2-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Aaron Tomlin
|
c5fd3ca06b |
slub: extend slub debug to handle multiple slabs
Extend the slub_debug syntax to "slub_debug=<flags>[,<slub>]*", where <slub> may contain an asterisk at the end. For example, the following would poison all kmalloc slabs: slub_debug=P,kmalloc* and the following would apply the default flags to all kmalloc and all block IO slabs: slub_debug=,bio*,kmalloc* Please note that a similar patch was posted by Iliyan Malchev some time ago but was never merged: https://marc.info/?l=linux-mm&m=131283905330474&w=2 Link: http://lkml.kernel.org/r/20180928111139.27962-1-atomlin@redhat.com Signed-off-by: Aaron Tomlin <atomlin@redhat.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: Iliyan Malchev <malchev@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Dmitry Vyukov
|
61448479a9 |
mm: don't warn about large allocations for slab
Slub does not call kmalloc_slab() for sizes > KMALLOC_MAX_CACHE_SIZE, instead it falls back to kmalloc_large(). For slab KMALLOC_MAX_CACHE_SIZE == KMALLOC_MAX_SIZE and it calls kmalloc_slab() for all allocations relying on NULL return value for over-sized allocations. This inconsistency leads to unwanted warnings from kmalloc_slab() for over-sized allocations for slab. Returning NULL for failed allocations is the expected behavior. Make slub and slab code consistent by checking size > KMALLOC_MAX_CACHE_SIZE in slab before calling kmalloc_slab(). While we are here also fix the check in kmalloc_slab(). We should check against KMALLOC_MAX_CACHE_SIZE rather than KMALLOC_MAX_SIZE. It all kinda worked because for slab the constants are the same, and slub always checks the size against KMALLOC_MAX_CACHE_SIZE before kmalloc_slab(). But if we get there with size > KMALLOC_MAX_CACHE_SIZE anyhow bad things will happen. For example, in case of a newly introduced bug in slub code. Also move the check in kmalloc_slab() from function entry to the size > 192 case. This partially compensates for the additional check in slab code and makes slub code a bit faster (at least theoretically). Also drop __GFP_NOWARN in the warning check. This warning means a bug in slab code itself, user-passed flags have nothing to do with it. Nothing of this affects slob. Link: http://lkml.kernel.org/r/20180927171502.226522-1-dvyukov@gmail.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: syzbot+87829a10073277282ad1@syzkaller.appspotmail.com Reported-by: syzbot+ef4e8fc3a06e9019bb40@syzkaller.appspotmail.com Reported-by: syzbot+6e438f4036df52cbb863@syzkaller.appspotmail.com Reported-by: syzbot+8574471d8734457d98aa@syzkaller.appspotmail.com Reported-by: syzbot+af1504df0807a083dbd9@syzkaller.appspotmail.com Acked-by: Christoph Lameter <cl@linux.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> 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> |
||
|
Andy Shevchenko
|
0684e6526e |
mm/slub.c: switch to bitmap_zalloc()
Switch to bitmap_zalloc() to show clearly what we are allocating. Besides that it returns pointer of bitmap type instead of opaque void *. Link: http://lkml.kernel.org/r/20180830104301.61649-1-andriy.shevchenko@linux.intel.com Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Christoph Lameter <cl@linux.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Tested-by: David Rientjes <rientjes@google.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> |
||
|
Linus Torvalds
|
26873acacb |
Driver core patches for 4.20-rc1
Driver core patches for 4.20-rc1 Here is a small number of driver core patches for 4.20-rc1. Not much happened here this merge window, only a very tiny number of patches that do: - add BUS_ATTR_WO() for use by drivers - component error path fixes - kernfs range check fix - other tiny error path fixes and const changes All of these have been in linux-next with no reported issues for a while. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -----BEGIN PGP SIGNATURE----- iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCW9Lhtw8cZ3JlZ0Brcm9h aC5jb20ACgkQMUfUDdst+ykHTgCguaJ3SgRefuC/WijjqboTC/SikCoAnRVTUxfU v8BisSN22kR3jmxwsXud =/IvY -----END PGP SIGNATURE----- Merge tag 'driver-core-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is a small number of driver core patches for 4.20-rc1. Not much happened here this merge window, only a very tiny number of patches that do: - add BUS_ATTR_WO() for use by drivers - component error path fixes - kernfs range check fix - other tiny error path fixes and const changes All of these have been in linux-next with no reported issues for a while" * tag 'driver-core-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: devres: provide devm_kstrdup_const() mm: move is_kernel_rodata() to asm-generic/sections.h devres: constify p in devm_kfree() driver core: add BUS_ATTR_WO() macro kernfs: Fix range checks in kernfs_get_target_path component: fix loop condition to call unbind() if bind() fails drivers/base/devtmpfs.c: don't pretend path is const in delete_path kernfs: update comment about kernfs_path() return value |
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|
Linus Torvalds
|
ba9f6f8954 |
Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull siginfo updates from Eric Biederman: "I have been slowly sorting out siginfo and this is the culmination of that work. The primary result is in several ways the signal infrastructure has been made less error prone. The code has been updated so that manually specifying SEND_SIG_FORCED is never necessary. The conversion to the new siginfo sending functions is now complete, which makes it difficult to send a signal without filling in the proper siginfo fields. At the tail end of the patchset comes the optimization of decreasing the size of struct siginfo in the kernel from 128 bytes to about 48 bytes on 64bit. The fundamental observation that enables this is by definition none of the known ways to use struct siginfo uses the extra bytes. This comes at the cost of a small user space observable difference. For the rare case of siginfo being injected into the kernel only what can be copied into kernel_siginfo is delivered to the destination, the rest of the bytes are set to 0. For cases where the signal and the si_code are known this is safe, because we know those bytes are not used. For cases where the signal and si_code combination is unknown the bits that won't fit into struct kernel_siginfo are tested to verify they are zero, and the send fails if they are not. I made an extensive search through userspace code and I could not find anything that would break because of the above change. If it turns out I did break something it will take just the revert of a single change to restore kernel_siginfo to the same size as userspace siginfo. Testing did reveal dependencies on preferring the signo passed to sigqueueinfo over si->signo, so bit the bullet and added the complexity necessary to handle that case. Testing also revealed bad things can happen if a negative signal number is passed into the system calls. Something no sane application will do but something a malicious program or a fuzzer might do. So I have fixed the code that performs the bounds checks to ensure negative signal numbers are handled" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (80 commits) signal: Guard against negative signal numbers in copy_siginfo_from_user32 signal: Guard against negative signal numbers in copy_siginfo_from_user signal: In sigqueueinfo prefer sig not si_signo signal: Use a smaller struct siginfo in the kernel signal: Distinguish between kernel_siginfo and siginfo signal: Introduce copy_siginfo_from_user and use it's return value signal: Remove the need for __ARCH_SI_PREABLE_SIZE and SI_PAD_SIZE signal: Fail sigqueueinfo if si_signo != sig signal/sparc: Move EMT_TAGOVF into the generic siginfo.h signal/unicore32: Use force_sig_fault where appropriate signal/unicore32: Generate siginfo in ucs32_notify_die signal/unicore32: Use send_sig_fault where appropriate signal/arc: Use force_sig_fault where appropriate signal/arc: Push siginfo generation into unhandled_exception signal/ia64: Use force_sig_fault where appropriate signal/ia64: Use the force_sig(SIGSEGV,...) in ia64_rt_sigreturn signal/ia64: Use the generic force_sigsegv in setup_frame signal/arm/kvm: Use send_sig_mceerr signal/arm: Use send_sig_fault where appropriate signal/arm: Use force_sig_fault where appropriate ... |
||
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Linus Torvalds
|
99792e0cea |
Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm updates from Ingo Molnar:
"Lots of changes in this cycle:
- Lots of CPA (change page attribute) optimizations and related
cleanups (Thomas Gleixner, Peter Zijstra)
- Make lazy TLB mode even lazier (Rik van Riel)
- Fault handler cleanups and improvements (Dave Hansen)
- kdump, vmcore: Enable kdumping encrypted memory with AMD SME
enabled (Lianbo Jiang)
- Clean up VM layout documentation (Baoquan He, Ingo Molnar)
- ... plus misc other fixes and enhancements"
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits)
x86/stackprotector: Remove the call to boot_init_stack_canary() from cpu_startup_entry()
x86/mm: Kill stray kernel fault handling comment
x86/mm: Do not warn about PCI BIOS W+X mappings
resource: Clean it up a bit
resource: Fix find_next_iomem_res() iteration issue
resource: Include resource end in walk_*() interfaces
x86/kexec: Correct KEXEC_BACKUP_SRC_END off-by-one error
x86/mm: Remove spurious fault pkey check
x86/mm/vsyscall: Consider vsyscall page part of user address space
x86/mm: Add vsyscall address helper
x86/mm: Fix exception table comments
x86/mm: Add clarifying comments for user addr space
x86/mm: Break out user address space handling
x86/mm: Break out kernel address space handling
x86/mm: Clarify hardware vs. software "error_code"
x86/mm/tlb: Make lazy TLB mode lazier
x86/mm/tlb: Add freed_tables element to flush_tlb_info
x86/mm/tlb: Add freed_tables argument to flush_tlb_mm_range
smp,cpumask: introduce on_each_cpu_cond_mask
smp: use __cpumask_set_cpu in on_each_cpu_cond
...
|
||
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Linus Torvalds
|
0200fbdd43 |
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking and misc x86 updates from Ingo Molnar:
"Lots of changes in this cycle - in part because locking/core attracted
a number of related x86 low level work which was easier to handle in a
single tree:
- Linux Kernel Memory Consistency Model updates (Alan Stern, Paul E.
McKenney, Andrea Parri)
- lockdep scalability improvements and micro-optimizations (Waiman
Long)
- rwsem improvements (Waiman Long)
- spinlock micro-optimization (Matthew Wilcox)
- qspinlocks: Provide a liveness guarantee (more fairness) on x86.
(Peter Zijlstra)
- Add support for relative references in jump tables on arm64, x86
and s390 to optimize jump labels (Ard Biesheuvel, Heiko Carstens)
- Be a lot less permissive on weird (kernel address) uaccess faults
on x86: BUG() when uaccess helpers fault on kernel addresses (Jann
Horn)
- macrofy x86 asm statements to un-confuse the GCC inliner. (Nadav
Amit)
- ... and a handful of other smaller changes as well"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
locking/lockdep: Make global debug_locks* variables read-mostly
locking/lockdep: Fix debug_locks off performance problem
locking/pvqspinlock: Extend node size when pvqspinlock is configured
locking/qspinlock_stat: Count instances of nested lock slowpaths
locking/qspinlock, x86: Provide liveness guarantee
x86/asm: 'Simplify' GEN_*_RMWcc() macros
locking/qspinlock: Rework some comments
locking/qspinlock: Re-order code
locking/lockdep: Remove duplicated 'lock_class_ops' percpu array
x86/defconfig: Enable CONFIG_USB_XHCI_HCD=y
futex: Replace spin_is_locked() with lockdep
locking/lockdep: Make class->ops a percpu counter and move it under CONFIG_DEBUG_LOCKDEP=y
x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs
x86/cpufeature: Macrofy inline assembly code to work around GCC inlining bugs
x86/extable: Macrofy inline assembly code to work around GCC inlining bugs
x86/paravirt: Work around GCC inlining bugs when compiling paravirt ops
x86/bug: Macrofy the BUG table section handling, to work around GCC inlining bugs
x86/alternatives: Macrofy lock prefixes to work around GCC inlining bugs
x86/refcount: Work around GCC inlining bug
x86/objtool: Use asm macros to work around GCC inlining bugs
...
|
||
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Linus Torvalds
|
6ab9e09238 |
for-4.20/block-20181021
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Merge tag 'for-4.20/block-20181021' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe:
"This is the main pull request for block changes for 4.20. This
contains:
- Series enabling runtime PM for blk-mq (Bart).
- Two pull requests from Christoph for NVMe, with items such as;
- Better AEN tracking
- Multipath improvements
- RDMA fixes
- Rework of FC for target removal
- Fixes for issues identified by static checkers
- Fabric cleanups, as prep for TCP transport
- Various cleanups and bug fixes
- Block merging cleanups (Christoph)
- Conversion of drivers to generic DMA mapping API (Christoph)
- Series fixing ref count issues with blkcg (Dennis)
- Series improving BFQ heuristics (Paolo, et al)
- Series improving heuristics for the Kyber IO scheduler (Omar)
- Removal of dangerous bio_rewind_iter() API (Ming)
- Apply single queue IPI redirection logic to blk-mq (Ming)
- Set of fixes and improvements for bcache (Coly et al)
- Series closing a hotplug race with sysfs group attributes (Hannes)
- Set of patches for lightnvm:
- pblk trace support (Hans)
- SPDX license header update (Javier)
- Tons of refactoring patches to cleanly abstract the 1.2 and 2.0
specs behind a common core interface. (Javier, Matias)
- Enable pblk to use a common interface to retrieve chunk metadata
(Matias)
- Bug fixes (Various)
- Set of fixes and updates to the blk IO latency target (Josef)
- blk-mq queue number updates fixes (Jianchao)
- Convert a bunch of drivers from the old legacy IO interface to
blk-mq. This will conclude with the removal of the legacy IO
interface itself in 4.21, with the rest of the drivers (me, Omar)
- Removal of the DAC960 driver. The SCSI tree will introduce two
replacement drivers for this (Hannes)"
* tag 'for-4.20/block-20181021' of git://git.kernel.dk/linux-block: (204 commits)
block: setup bounce bio_sets properly
blkcg: reassociate bios when make_request() is called recursively
blkcg: fix edge case for blk_get_rl() under memory pressure
nvme-fabrics: move controller options matching to fabrics
nvme-rdma: always have a valid trsvcid
mtip32xx: fully switch to the generic DMA API
rsxx: switch to the generic DMA API
umem: switch to the generic DMA API
sx8: switch to the generic DMA API
sx8: remove dead IF_64BIT_DMA_IS_POSSIBLE code
skd: switch to the generic DMA API
ubd: remove use of blk_rq_map_sg
nvme-pci: remove duplicate check
drivers/block: Remove DAC960 driver
nvme-pci: fix hot removal during error handling
nvmet-fcloop: suppress a compiler warning
nvme-core: make implicit seed truncation explicit
nvmet-fc: fix kernel-doc headers
nvme-fc: rework the request initialization code
nvme-fc: introduce struct nvme_fcp_op_w_sgl
...
|
||
|
Linus Torvalds
|
5289851171 |
arm64 updates for 4.20:
- Core mmu_gather changes which allow tracking the levels of page-table
being cleared together with the arm64 low-level flushing routines
- Support for the new ARMv8.5 PSTATE.SSBS bit which can be used to
mitigate Spectre-v4 dynamically without trapping to EL3 firmware
- Introduce COMPAT_SIGMINSTKSZ for use in compat_sys_sigaltstack
- Optimise emulation of MRS instructions to ID_* registers on ARMv8.4
- Support for Common Not Private (CnP) translations allowing threads of
the same CPU to share the TLB entries
- Accelerated crc32 routines
- Move swapper_pg_dir to the rodata section
- Trap WFI instruction executed in user space
- ARM erratum 1188874 workaround (arch_timer)
- Miscellaneous fixes and clean-ups
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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:
"Apart from some new arm64 features and clean-ups, this also contains
the core mmu_gather changes for tracking the levels of the page table
being cleared and a minor update to the generic
compat_sys_sigaltstack() introducing COMPAT_SIGMINSKSZ.
Summary:
- Core mmu_gather changes which allow tracking the levels of
page-table being cleared together with the arm64 low-level flushing
routines
- Support for the new ARMv8.5 PSTATE.SSBS bit which can be used to
mitigate Spectre-v4 dynamically without trapping to EL3 firmware
- Introduce COMPAT_SIGMINSTKSZ for use in compat_sys_sigaltstack
- Optimise emulation of MRS instructions to ID_* registers on ARMv8.4
- Support for Common Not Private (CnP) translations allowing threads
of the same CPU to share the TLB entries
- Accelerated crc32 routines
- Move swapper_pg_dir to the rodata section
- Trap WFI instruction executed in user space
- ARM erratum 1188874 workaround (arch_timer)
- Miscellaneous fixes and clean-ups"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (78 commits)
arm64: KVM: Guests can skip __install_bp_hardening_cb()s HYP work
arm64: cpufeature: Trap CTR_EL0 access only where it is necessary
arm64: cpufeature: Fix handling of CTR_EL0.IDC field
arm64: cpufeature: ctr: Fix cpu capability check for late CPUs
Documentation/arm64: HugeTLB page implementation
arm64: mm: Use __pa_symbol() for set_swapper_pgd()
arm64: Add silicon-errata.txt entry for ARM erratum 1188873
Revert "arm64: uaccess: implement unsafe accessors"
arm64: mm: Drop the unused cpu parameter
MAINTAINERS: fix bad sdei paths
arm64: mm: Use #ifdef for the __PAGETABLE_P?D_FOLDED defines
arm64: Fix typo in a comment in arch/arm64/mm/kasan_init.c
arm64: xen: Use existing helper to check interrupt status
arm64: Use daifflag_restore after bp_hardening
arm64: daifflags: Use irqflags functions for daifflags
arm64: arch_timer: avoid unused function warning
arm64: Trap WFI executed in userspace
arm64: docs: Document SSBS HWCAP
arm64: docs: Fix typos in ELF hwcaps
arm64/kprobes: remove an extra semicolon in arch_prepare_kprobe
...
|
||
|
Linus Torvalds
|
eb66ae0308 |
mremap: properly flush TLB before releasing the page
Jann Horn points out that our TLB flushing was subtly wrong for the mremap() case. What makes mremap() special is that we don't follow the usual "add page to list of pages to be freed, then flush tlb, and then free pages". No, mremap() obviously just _moves_ the page from one page table location to another. That matters, because mremap() thus doesn't directly control the lifetime of the moved page with a freelist: instead, the lifetime of the page is controlled by the page table locking, that serializes access to the entry. As a result, we need to flush the TLB not just before releasing the lock for the source location (to avoid any concurrent accesses to the entry), but also before we release the destination page table lock (to avoid the TLB being flushed after somebody else has already done something to that page). This also makes the whole "need_flush" logic unnecessary, since we now always end up flushing the TLB for every valid entry. Reported-and-tested-by: Jann Horn <jannh@google.com> Acked-by: Will Deacon <will.deacon@arm.com> Tested-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
|
Bartosz Golaszewski
|
59c3f82ad1 |
mm: move is_kernel_rodata() to asm-generic/sections.h
Export this routine so that we can use it later in devm_kstrdup_const() and devm_kfree(). Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
|
Jérôme Glisse
|
bfba8e5cf2 |
mm/thp: fix call to mmu_notifier in set_pmd_migration_entry() v2
Inside set_pmd_migration_entry() we are holding page table locks and thus we can not sleep so we can not call invalidate_range_start/end() So remove call to mmu_notifier_invalidate_range_start/end() because they are call inside the function calling set_pmd_migration_entry() (see try_to_unmap_one()). Link: http://lkml.kernel.org/r/20181012181056.7864-1-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Reported-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Zi Yan <zi.yan@cs.rutgers.edu> Acked-by: Michal Hocko <mhocko@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
|
Jann Horn
|
7aa867dd89 |
mm/mmap.c: don't clobber partially overlapping VMA with MAP_FIXED_NOREPLACE
Daniel Micay reports that attempting to use MAP_FIXED_NOREPLACE in an
application causes that application to randomly crash. The existing check
for handling MAP_FIXED_NOREPLACE looks up the first VMA that either
overlaps or follows the requested region, and then bails out if that VMA
overlaps *the start* of the requested region. It does not bail out if the
VMA only overlaps another part of the requested region.
Fix it by checking that the found VMA only starts at or after the end of
the requested region, in which case there is no overlap.
Test case:
user@debian:~$ cat mmap_fixed_simple.c
#include <sys/mman.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#ifndef MAP_FIXED_NOREPLACE
#define MAP_FIXED_NOREPLACE 0x100000
#endif
int main(void) {
char *p;
errno = 0;
p = mmap((void*)0x10001000, 0x4000, PROT_NONE,
MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED_NOREPLACE, -1, 0);
printf("p1=%p err=%m\n", p);
errno = 0;
p = mmap((void*)0x10000000, 0x2000, PROT_READ,
MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED_NOREPLACE, -1, 0);
printf("p2=%p err=%m\n", p);
char cmd[100];
sprintf(cmd, "cat /proc/%d/maps", getpid());
system(cmd);
return 0;
}
user@debian:~$ gcc -o mmap_fixed_simple mmap_fixed_simple.c
user@debian:~$ ./mmap_fixed_simple
p1=0x10001000 err=Success
p2=0x10000000 err=Success
10000000-10002000 r--p 00000000 00:00 0
10002000-10005000 ---p 00000000 00:00 0
564a9a06f000-564a9a070000 r-xp 00000000 fe:01 264004
/home/user/mmap_fixed_simple
564a9a26f000-564a9a270000 r--p 00000000 fe:01 264004
/home/user/mmap_fixed_simple
564a9a270000-564a9a271000 rw-p 00001000 fe:01 264004
/home/user/mmap_fixed_simple
564a9a54a000-564a9a56b000 rw-p 00000000 00:00 0 [heap]
7f8eba447000-7f8eba5dc000 r-xp 00000000 fe:01 405885
/lib/x86_64-linux-gnu/libc-2.24.so
7f8eba5dc000-7f8eba7dc000 ---p 00195000 fe:01 405885
/lib/x86_64-linux-gnu/libc-2.24.so
7f8eba7dc000-7f8eba7e0000 r--p 00195000 fe:01 405885
/lib/x86_64-linux-gnu/libc-2.24.so
7f8eba7e0000-7f8eba7e2000 rw-p 00199000 fe:01 405885
/lib/x86_64-linux-gnu/libc-2.24.so
7f8eba7e2000-7f8eba7e6000 rw-p 00000000 00:00 0
7f8eba7e6000-7f8eba809000 r-xp 00000000 fe:01 405876
/lib/x86_64-linux-gnu/ld-2.24.so
7f8eba9e9000-7f8eba9eb000 rw-p 00000000 00:00 0
7f8ebaa06000-7f8ebaa09000 rw-p 00000000 00:00 0
7f8ebaa09000-7f8ebaa0a000 r--p 00023000 fe:01 405876
/lib/x86_64-linux-gnu/ld-2.24.so
7f8ebaa0a000-7f8ebaa0b000 rw-p 00024000 fe:01 405876
/lib/x86_64-linux-gnu/ld-2.24.so
7f8ebaa0b000-7f8ebaa0c000 rw-p 00000000 00:00 0
7ffcc99fa000-7ffcc9a1b000 rw-p 00000000 00:00 0 [stack]
7ffcc9b44000-7ffcc9b47000 r--p 00000000 00:00 0 [vvar]
7ffcc9b47000-7ffcc9b49000 r-xp 00000000 00:00 0 [vdso]
ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0
[vsyscall]
user@debian:~$ uname -a
Linux debian 4.19.0-rc6+ #181 SMP Wed Oct 3 23:43:42 CEST 2018 x86_64 GNU/Linux
user@debian:~$
As you can see, the first page of the mapping at 0x10001000 was clobbered.
Link: http://lkml.kernel.org/r/20181010152736.99475-1-jannh@google.com
Fixes:
|
||
|
Greg Kroah-Hartman
|
a22dd3629e |
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Ingo writes: "scheduler fix: Cleanup of dead code left over from the recent sched/numa fixes." * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: mm, sched/numa: Remove remaining traces of NUMA rate-limiting |
||
|
Peter Zijlstra
|
a31acd3ee8 |
x86/mm: Page size aware flush_tlb_mm_range()
Use the new tlb_get_unmap_shift() to determine the stride of the INVLPG loop. Cc: Nick Piggin <npiggin@gmail.com> Cc: Will Deacon <will.deacon@arm.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> |
||
|
Peter Zijlstra
|
a5b966ae42 |
Merge branch 'tlb/asm-generic' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into x86/mm
Pull in the generic mmu_gather changes from the ARM64 tree such that we can put x86 specific things on top as well. |
||
|
Srikar Dronamraju
|
e054637597 |
mm, sched/numa: Remove remaining traces of NUMA rate-limiting
Remove the leftover pglist_data::numabalancing_migrate_lock and its
initialization, we stopped using this lock with:
|
||
|
Mike Rapoport
|
6685b35736 |
percpu: stop leaking bitmap metadata blocks
The commit |
||
|
Greg Kroah-Hartman
|
091a1eaa0e |
Merge branch 'akpm'
* akpm: mm: madvise(MADV_DODUMP): allow hugetlbfs pages ocfs2: fix locking for res->tracking and dlm->tracking_list mm/vmscan.c: fix int overflow in callers of do_shrink_slab() mm/vmstat.c: skip NR_TLB_REMOTE_FLUSH* properly mm/vmstat.c: fix outdated vmstat_text proc: restrict kernel stack dumps to root mm/hugetlb: add mmap() encodings for 32MB and 512MB page sizes mm/migrate.c: split only transparent huge pages when allocation fails ipc/shm.c: use ERR_CAST() for shm_lock() error return mm/gup_benchmark: fix unsigned comparison to zero in __gup_benchmark_ioctl mm, thp: fix mlocking THP page with migration enabled ocfs2: fix crash in ocfs2_duplicate_clusters_by_page() hugetlb: take PMD sharing into account when flushing tlb/caches mm: migration: fix migration of huge PMD shared pages |
||
|
Daniel Black
|
d41aa52523 |
mm: madvise(MADV_DODUMP): allow hugetlbfs pages
Reproducer, assuming 2M of hugetlbfs available:
Hugetlbfs mounted, size=2M and option user=testuser
# mount | grep ^hugetlbfs
hugetlbfs on /dev/hugepages type hugetlbfs (rw,pagesize=2M,user=dan)
# sysctl vm.nr_hugepages=1
vm.nr_hugepages = 1
# grep Huge /proc/meminfo
AnonHugePages: 0 kB
ShmemHugePages: 0 kB
HugePages_Total: 1
HugePages_Free: 1
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
Hugetlb: 2048 kB
Code:
#include <sys/mman.h>
#include <stddef.h>
#define SIZE 2*1024*1024
int main()
{
void *ptr;
ptr = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_HUGETLB | MAP_ANONYMOUS, -1, 0);
madvise(ptr, SIZE, MADV_DONTDUMP);
madvise(ptr, SIZE, MADV_DODUMP);
}
Compile and strace:
mmap(NULL, 2097152, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS|MAP_HUGETLB, -1, 0) = 0x7ff7c9200000
madvise(0x7ff7c9200000, 2097152, MADV_DONTDUMP) = 0
madvise(0x7ff7c9200000, 2097152, MADV_DODUMP) = -1 EINVAL (Invalid argument)
hugetlbfs pages have VM_DONTEXPAND in the VmFlags driver pages based on
author testing with analysis from Florian Weimer[1].
The inclusion of VM_DONTEXPAND into the VM_SPECIAL defination was a
consequence of the large useage of VM_DONTEXPAND in device drivers.
A consequence of [2] is that VM_DONTEXPAND marked pages are unable to be
marked DODUMP.
A user could quite legitimately madvise(MADV_DONTDUMP) their hugetlbfs
memory for a while and later request that madvise(MADV_DODUMP) on the same
memory. We correct this omission by allowing madvice(MADV_DODUMP) on
hugetlbfs pages.
[1] https://stackoverflow.com/questions/52548260/madvisedodump-on-the-same-ptr-size-as-a-successful-madvisedontdump-fails-wit
[2] commit
|
||
|
Kirill Tkhai
|
b8e57efa2c |
mm/vmscan.c: fix int overflow in callers of do_shrink_slab()
do_shrink_slab() returns unsigned long value, and the placing into int variable cuts high bytes off. Then we compare ret and 0xfffffffe (since SHRINK_EMPTY is converted to ret type). Thus a large number of objects returned by do_shrink_slab() may be interpreted as SHRINK_EMPTY, if low bytes of their value are equal to 0xfffffffe. Fix that by declaration ret as unsigned long in these functions. Link: http://lkml.kernel.org/r/153813407177.17544.14888305435570723973.stgit@localhost.localdomain Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Reported-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Shakeel Butt <shakeelb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
||
|
Jann Horn
|
58bc4c34d2 |
mm/vmstat.c: skip NR_TLB_REMOTE_FLUSH* properly
|
||
|
Jann Horn
|
28e2c4bb99 |
mm/vmstat.c: fix outdated vmstat_text
|
||
|
Anshuman Khandual
|
e6112fc300 |
mm/migrate.c: split only transparent huge pages when allocation fails
split_huge_page_to_list() fails on HugeTLB pages. I was experimenting
with moving 32MB contig HugeTLB pages on arm64 (with a debug patch
applied) and hit the following stack trace when the kernel crashed.
[ 3732.462797] Call trace:
[ 3732.462835] split_huge_page_to_list+0x3b0/0x858
[ 3732.462913] migrate_pages+0x728/0xc20
[ 3732.462999] soft_offline_page+0x448/0x8b0
[ 3732.463097] __arm64_sys_madvise+0x724/0x850
[ 3732.463197] el0_svc_handler+0x74/0x110
[ 3732.463297] el0_svc+0x8/0xc
[ 3732.463347] Code: d1000400 f90b0e60 f2fbd5a2 a94982a1 (f9000420)
When unmap_and_move[_huge_page]() fails due to lack of memory, the
splitting should happen only for transparent huge pages not for HugeTLB
pages. PageTransHuge() returns true for both THP and HugeTLB pages.
Hence the conditonal check should test PagesHuge() flag to make sure that
given pages is not a HugeTLB one.
Link: http://lkml.kernel.org/r/1537798495-4996-1-git-send-email-anshuman.khandual@arm.com
Fixes:
|
||
|
YueHaibing
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5189686457 |
mm/gup_benchmark: fix unsigned comparison to zero in __gup_benchmark_ioctl
get_user_pages_fast() will return negative value if no pages were pinned,
then be converted to a unsigned, which is compared to zero, giving the
wrong result.
Link: http://lkml.kernel.org/r/20180921095015.26088-1-yuehaibing@huawei.com
Fixes:
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Kirill A. Shutemov
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e125fe405a |
mm, thp: fix mlocking THP page with migration enabled
A transparent huge page is represented by a single entry on an LRU list.
Therefore, we can only make unevictable an entire compound page, not
individual subpages.
If a user tries to mlock() part of a huge page, we want the rest of the
page to be reclaimable.
We handle this by keeping PTE-mapped huge pages on normal LRU lists: the
PMD on border of VM_LOCKED VMA will be split into PTE table.
Introduction of THP migration breaks[1] the rules around mlocking THP
pages. If we had a single PMD mapping of the page in mlocked VMA, the
page will get mlocked, regardless of PTE mappings of the page.
For tmpfs/shmem it's easy to fix by checking PageDoubleMap() in
remove_migration_pmd().
Anon THP pages can only be shared between processes via fork(). Mlocked
page can only be shared if parent mlocked it before forking, otherwise CoW
will be triggered on mlock().
For Anon-THP, we can fix the issue by munlocking the page on removing PTE
migration entry for the page. PTEs for the page will always come after
mlocked PMD: rmap walks VMAs from oldest to newest.
Test-case:
#include <unistd.h>
#include <sys/mman.h>
#include <sys/wait.h>
#include <linux/mempolicy.h>
#include <numaif.h>
int main(void)
{
unsigned long nodemask = 4;
void *addr;
addr = mmap((void *)0x20000000UL, 2UL << 20, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_LOCKED, -1, 0);
if (fork()) {
wait(NULL);
return 0;
}
mlock(addr, 4UL << 10);
mbind(addr, 2UL << 20, MPOL_PREFERRED | MPOL_F_RELATIVE_NODES,
&nodemask, 4, MPOL_MF_MOVE);
return 0;
}
[1] https://lkml.kernel.org/r/CAOMGZ=G52R-30rZvhGxEbkTw7rLLwBGadVYeo--iizcD3upL3A@mail.gmail.com
Link: http://lkml.kernel.org/r/20180917133816.43995-1-kirill.shutemov@linux.intel.com
Fixes:
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Mike Kravetz
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dff11abe28 |
hugetlb: take PMD sharing into account when flushing tlb/caches
When fixing an issue with PMD sharing and migration, it was discovered via code inspection that other callers of huge_pmd_unshare potentially have an issue with cache and tlb flushing. Use the routine adjust_range_if_pmd_sharing_possible() to calculate worst case ranges for mmu notifiers. Ensure that this range is flushed if huge_pmd_unshare succeeds and unmaps a PUD_SUZE area. Link: http://lkml.kernel.org/r/20180823205917.16297-3-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |