There are 3 memory models, FLATMEM, DISCONTIGMEM, SPARSEMEM.
Each arch has its own page_to_pfn(), pfn_to_page() for each models.
But most of them can use the same arithmetic.
This patch adds asm-generic/memory_model.h, which includes generic
page_to_pfn(), pfn_to_page() definitions for each memory model.
When CONFIG_OUT_OF_LINE_PFN_TO_PAGE=y, out-of-line functions are
used instead of macro. This is enabled by some archs and reduces
text size.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial:
drivers/char/ftape/lowlevel/fdc-io.c: Correct a comment
Kconfig help: MTD_JEDECPROBE already supports Intel
Remove ugly debugging stuff
do_mounts.c: Minor ROOT_DEV comment cleanup
BUG_ON() Conversion in drivers/s390/block/dasd_devmap.c
BUG_ON() Conversion in mm/mempool.c
BUG_ON() Conversion in mm/memory.c
BUG_ON() Conversion in kernel/fork.c
BUG_ON() Conversion in ipc/sem.c
BUG_ON() Conversion in fs/ext2/
BUG_ON() Conversion in fs/hfs/
BUG_ON() Conversion in fs/dcache.c
BUG_ON() Conversion in fs/buffer.c
BUG_ON() Conversion in input/serio/hp_sdc_mlc.c
BUG_ON() Conversion in md/dm-table.c
BUG_ON() Conversion in md/dm-path-selector.c
BUG_ON() Conversion in drivers/isdn
BUG_ON() Conversion in drivers/char
BUG_ON() Conversion in drivers/mtd/
Add another allocator to the common mempool code: a kzalloc/kfree allocator
This will be used by the next patch in the series to replace a mempool-backed
kzalloc allocator. It is also very likely that there will be more users in
the future.
Signed-off-by: Matthew Dobson <colpatch@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add another allocator to the common mempool code: a kmalloc/kfree allocator
This will be used by the next patch in the series to replace duplicate
mempool-backed kmalloc allocators in several places in the kernel. It is also
very likely that there will be more users in the future.
Signed-off-by: Matthew Dobson <colpatch@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Convert two mempool users that currently use their own mempool-backed page
allocators to use the generic mempool page allocator.
Also included are 2 trivial whitespace fixes.
Signed-off-by: Matthew Dobson <colpatch@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This will be used by the next patch in the series to replace duplicate
mempool-backed page allocators in 2 places in the kernel. It is also likely
that there will be more users in the future.
Signed-off-by: Matthew Dobson <colpatch@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Currently, get_user_pages() returns fully coherent pages to the kernel for
anything other than anonymous pages. This is a problem for things like
fuse and the SCSI generic ioctl SG_IO which can potentially wish to do DMA
to anonymous pages passed in by users.
The fix is to add a new memory management API: flush_anon_page() which
is used in get_user_pages() to make anonymous pages coherent.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
this changes if() BUG(); constructs to BUG_ON() which is
cleaner, contains unlikely() and can better optimized away.
Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
This fixes problems with very large nodes (over 128GB) filling up all of
the first 4GB with their mem_map and not leaving enough space for the
swiotlb.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Hugh is rightly concerned that the CONFIG_DEBUG_VM coverage has gone too
far in vm_normal_page, considering that we expect production kernels to be
shipped with the option turned off, and that the code has been under some
large changes recently.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: (21 commits)
BUG_ON() Conversion in drivers/video/
BUG_ON() Conversion in drivers/parisc/
BUG_ON() Conversion in drivers/block/
BUG_ON() Conversion in sound/sparc/cs4231.c
BUG_ON() Conversion in drivers/s390/block/dasd.c
BUG_ON() Conversion in lib/swiotlb.c
BUG_ON() Conversion in kernel/cpu.c
BUG_ON() Conversion in ipc/msg.c
BUG_ON() Conversion in block/elevator.c
BUG_ON() Conversion in fs/coda/
BUG_ON() Conversion in fs/binfmt_elf_fdpic.c
BUG_ON() Conversion in input/serio/hil_mlc.c
BUG_ON() Conversion in md/dm-hw-handler.c
BUG_ON() Conversion in md/bitmap.c
The comment describing how MS_ASYNC works in msync.c is confusing
rcu: undeclared variable used in documentation
fix typos "wich" -> "which"
typo patch for fs/ufs/super.c
Fix simple typos
tabify drivers/char/Makefile
...
The "rounded up to nearest power of 2 in size" algorithm in
alloc_large_system_hash is not correct. As coded, it takes an otherwise
acceptable power-of-2 value and doubles it. For example, we see the error
if we boot with thash_entries=2097152 which produces a hash table with
4194304 entries.
Signed-off-by: John Hawkes <hawkes@sgi.com>
Cc: Roland Dreier <rdreier@cisco.com>
Cc: "Chen, Kenneth W" <kenneth.w.chen@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A couple of places are forgetting to take it.
The kswapd case is probably unimportant. keventd_create_kthread() was racy.
The whole thing is a bit flakey: you start a kernel thread, get its pid from
kernel_thread() then look up its task_struct.
a) It assumes that pid recycling takes a "long" time.
b) We get a task_struct but no reference was taken on it. The owner of the
kswapd and kthread task_struct*'s must assume that the new thread won't
exit unexpectedly. Because if it does, they're left holding dead memory
and any attempt to control or stop that task will crash.
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In zone_pcp_init we print out all zones even if they are empty:
On node 0 totalpages: 245760
DMA zone: 245760 pages, LIFO batch:31
DMA32 zone: 0 pages, LIFO batch:0
Normal zone: 0 pages, LIFO batch:0
HighMem zone: 0 pages, LIFO batch:0
To conserve dmesg space why not print only the non zero zones.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The page migration code could function without NUMA but we currently have
no users for the non-NUMA case.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We have had this memory leak for a while now. The situation is complicated
by the use of alloc_kmemlist() as a function to resize various caches by
do_tune_cpucache().
What we do here is first of all make sure that we deallocate properly in
the loop over all the nodes.
If we are just resizing caches then we can simply return with -ENOMEM if an
allocation fails.
If the cache is new then we need to rollback and remove all earlier
allocations.
We detect that a cache is new by checking if the link to the global cache
chain has been setup. This is a bit hackish ....
(also fix up too overlong lines that I added in the last patch...)
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Inspired by Jesper Juhl's patch from today
1. Get rid of err
We do not set it to anything else but zero.
2. Drop the CONFIG_NUMA stuff.
There are definitions for alloc_alien_cache and free_alien_cache()
that do the right thing for the non NUMA case.
3. Better naming of variables.
4. Remove redundant cachep->nodelists[node] expressions.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
__drain_alien_cache() currently drains objects by freeing them to the
(remote) freelists of the original node. However, each node also has a
shared list containing objects to be used on any processor of that node.
We can avoid a number of remote node accesses by copying the pointers to
the free objects directly into the remote shared array.
And while we are at it: Skip alien draining if the alien cache spinlock is
already taken.
Kiran reported that this is a performance benefit.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
slabr_objects() can be used to transfer objects between various object
caches of the slab allocator. It is currently only used during
__cache_alloc() to retrieve elements from the shared array. We will be
using it soon to transfer elements from the alien caches to the remote
shared array.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Convert mm/ to use the new kmem_cache_zalloc allocator.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
As suggested by Eric Dumazet, optimize kzalloc() calls that pass a
compile-time constant size. Please note that the patch increases kernel
text slightly (~200 bytes for defconfig on x86).
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Introduce a memory-zeroing variant of kmem_cache_alloc. The allocator
already exits in XFS and there are potential users for it so this patch
makes the allocator available for the general public.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch series creates a strndup_user() function to easy copying C strings
from userspace. Also we avoid common pitfalls like userspace modifying the
final \0 after the strlen_user().
Signed-off-by: Davi Arnaut <davi.arnaut@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
No need to duplicate all that code.
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
msync() does a strange thing. Essentially:
vma = find_vma();
for ( ; ; ) {
if (!vma)
return -ENOMEM;
...
vma = vma->vm_next;
}
so an msync() request which starts within or before a valid VMA and which ends
within or beyond the final VMA will incorrectly return -ENOMEM.
Fix.
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It seems bad to hold mmap_sem while performing synchronous disk I/O. Alter
the msync(MS_SYNC) code so that the lock is released while we sync the file.
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It seems sensible to perform dirty page throttling in msync: as the application
dirties pages we can kick off pdflush early, or even force the msync() caller
to perform writeout, or even throttle the msync() caller.
The main effect of this is to start disk writeback earlier if we've just
discovered that a large amount of pagecache has been dirtied. (Otherwise it
wouldn't happen for up to five seconds, next time pdflush wakes up).
It also will cause the page-dirtying process to get panalised for dirtying
those pages rather than whacking someone else with the problem.
We should do this for munmap() and possibly even exit(), too.
We drop the mmap_sem while performing the dirty page balancing. It doesn't
seem right to hold mmap_sem for that long.
Note that this patch only affects MS_ASYNC. MS_SYNC will be syncing all the
dirty pages anyway.
We note that msync(MS_SYNC) does a full-file-sync inside mmap_sem, and always
has. We can fix that up...
The patch also tightens up the mmap_sem coverage in sys_msync(): no point in
taking it while we perform the incoming arg checking.
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We need set_page_dirty() to return true if it actually transitioned the page
from a clean to dirty state. This wasn't right in a couple of places. Do a
kernel-wide audit, fix things up.
This leaves open the possibility of returning a negative errno from
set_page_dirty() sometime in the future. But we don't do that at present.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Modify balance_dirty_pages_ratelimited() so that it can take a
number-of-pages-which-I-just-dirtied argument. For msync().
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add two new linux-specific fadvise extensions():
LINUX_FADV_ASYNC_WRITE: start async writeout of any dirty pages between file
offsets `offset' and `offset+len'. Any pages which are currently under
writeout are skipped, whether or not they are dirty.
LINUX_FADV_WRITE_WAIT: wait upon writeout of any dirty pages between file
offsets `offset' and `offset+len'.
By combining these two operations the application may do several things:
LINUX_FADV_ASYNC_WRITE: push some or all of the dirty pages at the disk.
LINUX_FADV_WRITE_WAIT, LINUX_FADV_ASYNC_WRITE: push all of the currently dirty
pages at the disk.
LINUX_FADV_WRITE_WAIT, LINUX_FADV_ASYNC_WRITE, LINUX_FADV_WRITE_WAIT: push all
of the currently dirty pages at the disk, wait until they have been written.
It should be noted that none of these operations write out the file's
metadata. So unless the application is strictly performing overwrites of
already-instantiated disk blocks, there are no guarantees here that the data
will be available after a crash.
To complete this suite of operations I guess we should have a "sync file
metadata only" operation. This gives applications access to all the building
blocks needed for all sorts of sync operations. But sync-metadata doesn't fit
well with the fadvise() interface. Probably it should be a new syscall:
sys_fmetadatasync().
The patch also diddles with the meaning of `endbyte' in sys_fadvise64_64().
It is made to represent that last affected byte in the file (ie: it is
inclusive). Generally, all these byterange and pagerange functions are
inclusive so we can easily represent EOF with -1.
As Ulrich notes, these two functions are somewhat abusive of the fadvise()
concept, which appears to be "set the future policy for this fd".
But these commands are a perfect fit with the fadvise() impementation, and
several of the existing fadvise() commands are synchronous and don't affect
future policy either. I think we can live with the slight incongruity.
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
I had trouble understanding working out whether filemap_fdatawrite_range()'s
`end' parameter describes the last-byte-to-be-written or the last-plus-one.
Clarify that in comments.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The hook in the slab cache allocation path to handle cpuset memory
spreading for tasks in cpusets with 'memory_spread_slab' enabled has a
modest performance bug. The hook calls into the memory spreading handler
alternate_node_alloc() if either of 'memory_spread_slab' or
'memory_spread_page' is enabled, even though the handler does nothing
(albeit harmlessly) for the page case
Fix - drop PF_SPREAD_PAGE from the set of flag bits that are used to
trigger a call to alternate_node_alloc().
The page case is handled by separate hooks -- see the calls conditioned on
cpuset_do_page_mem_spread() in mm/filemap.c
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The hooks in the slab cache allocator code path for support of NUMA
mempolicies and cpuset memory spreading are in an important code path. Many
systems will use neither feature.
This patch optimizes those hooks down to a single check of some bits in the
current tasks task_struct flags. For non NUMA systems, this hook and related
code is already ifdef'd out.
The optimization is done by using another task flag, set if the task is using
a non-default NUMA mempolicy. Taking this flag bit along with the
PF_SPREAD_PAGE and PF_SPREAD_SLAB flag bits added earlier in this 'cpuset
memory spreading' patch set, one can check for the combination of any of these
special case memory placement mechanisms with a single test of the current
tasks task_struct flags.
This patch also tightens up the code, to save a few bytes of kernel text
space, and moves some of it out of line. Due to the nested inlines called
from multiple places, we were ending up with three copies of this code, which
once we get off the main code path (for local node allocation) seems a bit
wasteful of instruction memory.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Provide the slab cache infrastructure to support cpuset memory spreading.
See the previous patches, cpuset_mem_spread, for an explanation of cpuset
memory spreading.
This patch provides a slab cache SLAB_MEM_SPREAD flag. If set in the
kmem_cache_create() call defining a slab cache, then any task marked with the
process state flag PF_MEMSPREAD will spread memory page allocations for that
cache over all the allowed nodes, instead of preferring the local (faulting)
node.
On systems not configured with CONFIG_NUMA, this results in no change to the
page allocation code path for slab caches.
On systems with cpusets configured in the kernel, but the "memory_spread"
cpuset option not enabled for the current tasks cpuset, this adds a call to a
cpuset routine and failed bit test of the processor state flag PF_SPREAD_SLAB.
For tasks so marked, a second inline test is done for the slab cache flag
SLAB_MEM_SPREAD, and if that is set and if the allocation is not
in_interrupt(), this adds a call to to a cpuset routine that computes which of
the tasks mems_allowed nodes should be preferred for this allocation.
==> This patch adds another hook into the performance critical
code path to allocating objects from the slab cache, in the
____cache_alloc() chunk, below. The next patch optimizes this
hook, reducing the impact of the combined mempolicy plus memory
spreading hooks on this critical code path to a single check
against the tasks task_struct flags word.
This patch provides the generic slab flags and logic needed to apply memory
spreading to a particular slab.
A subsequent patch will mark a few specific slab caches for this placement
policy.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Change the page cache allocation calls to support cpuset memory spreading.
See the previous patch, cpuset_mem_spread, for an explanation of cpuset memory
spreading.
On systems without cpusets configured in the kernel, this is no change.
On systems with cpusets configured in the kernel, but the "memory_spread"
cpuset option not enabled for the current tasks cpuset, this adds a call to a
cpuset routine and failed bit test of the processor state flag PF_SPREAD_PAGE.
On tasks in cpusets with "memory_spread" enabled, this adds a call to a cpuset
routine that computes which of the tasks mems_allowed nodes should be
preferred for this allocation.
If memory spreading applies to a particular allocation, then any other NUMA
mempolicy does not apply.
Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If we get under some memory pressure in a cpuset (we only scan zones that
are in the cpuset for memory) then kswapd is woken up for all zones. This
patch only wakes up kswapd in zones that are part of the current cpuset.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make that the internal value for /proc/sys/vm/laptop_mode is stored as
jiffies instead of seconds. Let the sysctl interface do the conversions,
instead of doing on-the-fly conversions every time the value is used.
Add a description of the fact that laptop_mode doubles as a flag and a
timeout to the comment above the laptop_mode variable.
Signed-off-by: Bart Samwel <bart@samwel.tk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make that the internal values for:
/proc/sys/vm/dirty_writeback_centisecs
/proc/sys/vm/dirty_expire_centisecs
are stored as jiffies instead of centiseconds. Let the sysctl interface do
the conversions with full precision using clock_t_to_jiffies, instead of
doing overflow-sensitive on-the-fly conversions every time the values are
used.
Cons: apparent precision loss if HZ is not a multiple of 100, because of
conversion back and forth. This is a common problem for all sysctl values
that use proc_dointvec_userhz_jiffies. (There is only one other in-tree
use, in net/core/neighbour.c.)
Signed-off-by: Bart Samwel <bart@samwel.tk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Linus points out that ext3_readdir's readahead only cuts in when
ext3_readdir() is operating at the very start of the directory. So for large
directories we end up performing no readahead at all and we suck.
So take it all out and use the core VM's page_cache_readahead(). This means
that ext3 directory reads will use all of readahead's dynamic sizing goop.
Note that we're using the directory's filp->f_ra to hold the readahead state,
but readahead is actually being performed against the underlying blockdev's
address_space. Fortunately the readahead code is all set up to handle this.
Tested with printk. It works. I was struggling to find a real workload which
actually cared.
(The patch also exports page_cache_readahead() to GPL modules)
Cc: "Stephen C. Tweedie" <sct@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch introduces a user space interface for swsusp.
The interface is based on a special character device, called the snapshot
device, that allows user space processes to perform suspend and resume-related
operations with the help of some ioctls and the read()/write() functions.
Additionally it allows these processes to allocate free swap pages from a
selected swap partition, called the resume partition, so that they know which
sectors of the resume partition are available to them.
The interface uses the same low-level system memory snapshot-handling
functions that are used by the built-it swap-writing/reading code of swsusp.
The interface documentation is included in the patch.
The patch assumes that the major and minor numbers of the snapshot device will
be 10 (ie. misc device) and 231, the registration of which has already been
requested.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Introduce the low level interface that can be used for handling the
snapshot of the system memory by the in-kernel swap-writing/reading code of
swsusp and the userland interface code (to be introduced shortly).
Also change the way in which swsusp records the allocated swap pages and,
consequently, simplifies the in-kernel swap-writing/reading code (this is
necessary for the userland interface too). To this end, it introduces two
helper functions in mm/swapfile.c, so that the swsusp code does not refer
directly to the swap internals.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Centralize the page migration functions in anticipation of additional
tinkering. Creates a new file mm/migrate.c
1. Extract buffer_migrate_page() from fs/buffer.c
2. Extract central migration code from vmscan.c
3. Extract some components from mempolicy.c
4. Export pageout() and remove_from_swap() from vmscan.c
5. Make it possible to configure NUMA systems without page migration
and non-NUMA systems with page migration.
I had to so some #ifdeffing in mempolicy.c that may need a cleanup.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The alien cache rotor in mm/slab.c assumes that the first online node is
node 0. Eventually for some archs, especially with hotplug, this will no
longer be true.
Fix the interleave rotor to handle the general case of node numbering.
Signed-off-by: Paul Jackson <pj@sgi.com>
Acked-by: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix bogus node loop in hugetlb.c alloc_fresh_huge_page(), which was
assuming that nodes are numbered contiguously from 0 to num_online_nodes().
Once the hotplug folks get this far, that will be false.
Signed-off-by: Paul Jackson <pj@sgi.com>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When we've allocated SWAPFILE_CLUSTER pages, ->cluster_next should be the
first index of swap cluster. But current code probably sets it wrong offset.
Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1. Only disable interrupts if there is actually something to free
2. Only dirty the pcp cacheline if we actually freed something.
3. Disable interrupts for each single pcp and not for cleaning
all the pcps in all zones of a node.
drain_node_pages is called every 2 seconds from cache_reap. This
fix should avoid most disabling of interrupts.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
