Commit Graph

514 Commits

Author SHA1 Message Date
Randy Dunlap 55a4462af5 page_alloc: fix kernel-doc warning
Ummark function as having kernel-doc notation, fixing the kernel-doc
warning.

Warning(mm/page_alloc.c:4519): No description found for parameter 'zone'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:26 -07:00
Shaohua Li 8e7e40d965 memory hotplug: make pages from movable zone always isolatable
Pages on movable zone have two types, MIGRATE_MOVABLE and MIGRATE_RESERVE,
both them can be movable, because only movable memory allocation can get
pages from movable zone.  This makes pages in movable zone always be able
to migrate.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Yakui Zhao <yakui.zhao@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:26 -07:00
Shaohua Li 6fb332fabd memory hotplug: exclude isolated page from pco page alloc
Pages marked as isolated should not be allocated again.  If such pages
reside in pcp list, they can be allocated too, so there is a ping-pong
memory offline frees some pages to pcp list and the pages get allocated
and then memory offline frees them again, this loop will happen again and
again.

This should have no impact in normal code path, because in normal code
path, pages in pcp list aren't isolated, and below loop will break in the
first entry.

Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Yakui Zhao <yakui.zhao@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:25 -07:00
Shaohua Li 112067f090 memory hotplug: update zone pcp at memory online
In my test, 128M memory is hot added, but zone's pcp batch is 0, which is
an obvious error.  When pages are onlined, zone pcp should be updated
accordingly.

[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Yakui Zhao <yakui.zhao@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:25 -07:00
David Rientjes 478b81fd84 mm: remove obsoleted alloc_pages cpuset comment
When a cpuset's nodemask is updated, all attached tasks have their cached
task->mems_allowed updated by a heap instead of requiring an explicit call
to cpuset_update_task_memory_state(), which has since been removed in
58568d2a82 ("cpuset,mm: update tasks'
mems_allowed in time").

Remove the obsoleted comment from the page allocator.

Cc: Paul Menage <menage@google.com>
Acked-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22 07:17:25 -07:00
Wu Fengguang 2a7684a23e HWPOISON: check and isolate corrupted free pages v2
If memory corruption hits the free buddy pages, we can safely ignore them.
No one will access them until page allocation time, then prep_new_page()
will automatically check and isolate PG_hwpoison page for us (for 0-order
allocation).

This patch expands prep_new_page() to check every component page in a high
order page allocation, in order to completely stop PG_hwpoison pages from
being recirculated.

Note that the common case -- only allocating a single page, doesn't
do any more work than before. Allocating > order 0 does a bit more work,
but that's relatively uncommon.

This simple implementation may drop some innocent neighbor pages, hopefully
it is not a big problem because the event should be rare enough.

This patch adds some runtime costs to high order page users.

[AK: Improved description]

v2: Andi Kleen:
Port to -mm code
Move check into separate function.
Don't dump stack in bad_pages for hwpoisoned pages.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-09-16 11:50:12 +02:00
Mel Gorman dd5d241ea9 page-allocator: always change pageblock ownership when anti-fragmentation is disabled
On low-memory systems, anti-fragmentation gets disabled as fragmentation
cannot be avoided on a sufficiently large boundary to be worthwhile.  Once
disabled, there is a period of time when all the pageblocks are marked
MOVABLE and the expectation is that they get marked UNMOVABLE at each call
to __rmqueue_fallback().

However, when MAX_ORDER is large the pageblocks do not change ownership
because the normal criteria are not met.  This has the effect of
prematurely breaking up too many large contiguous blocks.  This is most
serious on NOMMU systems which depend on high-order allocations to boot.
This patch causes pageblocks to change ownership on every fallback when
anti-fragmentation is disabled.  This prevents the large blocks being
prematurely broken up.

This is a fix to commit 49255c619f [page
allocator: move check for disabled anti-fragmentation out of fastpath] and
the problem affects 2.6.31-rc8.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Tested-by: Paul Mundt <lethal@linux-sh.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-05 11:30:42 -07:00
Bo Liu 7f9cfb3103 mm: build_zonelists(): move clear node_load[] to __build_all_zonelists()
If node_load[] is cleared everytime build_zonelists() is
called,node_load[] will have no help to find the next node that should
appear in the given node's fallback list.

Because of the bug, zonelist's node_order is not calculated as expected.
This bug affects on big machine, which has asynmetric node distance.

[synmetric NUMA's node distance]
     0    1    2
0   10   12   12
1   12   10   12
2   12   12   10

[asynmetric NUMA's node distance]
     0    1    2
0   10   12   20
1   12   10   14
2   20   14   10

This (my bug) is very old but no one has reported this for a long time.
Maybe because the number of asynmetric NUMA is very small and they use
cpuset for customizing node memory allocation fallback.

[akpm@linux-foundation.org: fix CONFIG_NUMA=n build]
Signed-off-by: Bo Liu <bo-liu@hotmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-08-18 16:31:13 -07:00
Mel Gorman 1fc28b70fe page-allocator: allow too high-order warning messages to be suppressed with __GFP_NOWARN
The page allocator warns once when an order >= MAX_ORDER is specified.
This is to catch callers of the allocator that are always falling back to
their worst-case when it was not expected.  However, there are cases where
the caller is behaving correctly but cannot suppress the warning.  This
patch allows the warning to be suppressed by the callers by specifying
__GFP_NOWARN.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-29 19:10:35 -07:00
David Rientjes 6583bb64fc mm: avoid endless looping for oom killed tasks
If a task is oom killed and still cannot find memory when trying with
no watermarks, it's better to fail the allocation attempt than to loop
endlessly.  Direct reclaim has already failed and the oom killer will
be a no-op since current has yet to die, so there is no other
alternative for allocations that are not __GFP_NOFAIL.

Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-29 19:10:34 -07:00
Mel Gorman e084b2d95e page-allocator: preserve PFN ordering when __GFP_COLD is set
Fix a post-2.6.24 performace regression caused by
3dfa5721f1 ("page-allocator: preserve PFN
ordering when __GFP_COLD is set").

Narayanan reports "The regression is around 15%.  There is no disk controller
as our setup is based on Samsung OneNAND used as a memory mapped device on a
OMAP2430 based board."

The page allocator tries to preserve contiguous PFN ordering when returning
pages such that repeated callers to the allocator have a strong chance of
getting physically contiguous pages, particularly when external fragmentation
is low.  However, of the bulk of the allocations have __GFP_COLD set as they
are due to aio_read() for example, then the PFNs are in reverse PFN order.
This can cause performance degration when used with IO controllers that could
have merged the requests.

This patch attempts to preserve the contiguous ordering of PFNs for users of
__GFP_COLD.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reported-by: Narayananu Gopalakrishnan <narayanan.g@samsung.com>
Tested-by: Narayanan Gopalakrishnan <narayanan.g@samsung.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-29 19:10:34 -07:00
Linus Torvalds 7638d5322b Merge branch 'kmemleak' of git://linux-arm.org/linux-2.6
* 'kmemleak' of git://linux-arm.org/linux-2.6:
  kmemleak: Remove alloc_bootmem annotations introduced in the past
  kmemleak: Add callbacks to the bootmem allocator
  kmemleak: Allow partial freeing of memory blocks
  kmemleak: Trace the kmalloc_large* functions in slub
  kmemleak: Scan objects allocated during a scanning episode
  kmemleak: Do not acquire scan_mutex in kmemleak_open()
  kmemleak: Remove the reported leaks number limitation
  kmemleak: Add more cond_resched() calls in the scanning thread
  kmemleak: Renice the scanning thread to +10
2009-07-12 12:24:35 -07:00
Jens Axboe 8aa7e847d8 Fix congestion_wait() sync/async vs read/write confusion
Commit 1faa16d228 accidentally broke
the bdi congestion wait queue logic, causing us to wait on congestion
for WRITE (== 1) when we really wanted BLK_RW_ASYNC (== 0) instead.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-07-10 20:31:53 +02:00
Catalin Marinas 264ef8a904 kmemleak: Remove alloc_bootmem annotations introduced in the past
kmemleak_alloc() calls were added in some places where alloc_bootmem was
called. Since now kmemleak tracks bootmem allocations, these explicit
calls should be run.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-07-09 17:07:02 +01:00
Kevin Cernekee 5bfd756097 Fix virt_to_phys() warnings
These warnings were observed on MIPS32 using 2.6.31-rc1 and gcc-4.2.0:

mm/page_alloc.c: In function 'alloc_pages_exact':
mm/page_alloc.c:1986: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast

drivers/usb/mon/mon_bin.c: In function 'mon_alloc_buff':
drivers/usb/mon/mon_bin.c:1264: warning: passing argument 1 of 'virt_to_phys' makes pointer from integer without a cast

[akpm@linux-foundation.org: fix kernel/perf_counter.c too]
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-06 13:57:03 -07:00
Yinghai Lu 66918dcdf9 x86: only clear node_states for 64bit
Nathan reported that

| commit 73d60b7f74
| Author: Yinghai Lu <yinghai@kernel.org>
| Date:   Tue Jun 16 15:33:00 2009 -0700
|
|    page-allocator: clear N_HIGH_MEMORY map before we set it again
|
|    SRAT tables may contains nodes of very small size.  The arch code may
|    decide to not activate such a node.  However, currently the early boot
|    code sets N_HIGH_MEMORY for such nodes.  These nodes therefore seem to be
|    active although these nodes have no present pages.
|
|    For 64bit N_HIGH_MEMORY == N_NORMAL_MEMORY, so that works for 64 bit too

unintentionally and incorrectly clears the cpuset.mems cgroup attribute on
an i386 kvm guest, meaning that cpuset.mems can not be used.

Fix this by only clearing node_states[N_NORMAL_MEMORY] for 64bit only.
and need to do save/restore for that in find_zone_movable_pfn

Reported-by: Nathan Lynch <ntl@pobox.com>
Tested-by: Nathan Lynch <ntl@pobox.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>,
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-30 18:56:01 -07:00
Linus Torvalds 4923abf9f1 Don't warn about order-1 allocations with __GFP_NOFAIL
Traditionally, we never failed small orders (even regardless of any
__GFP_NOFAIL flags), and slab will allocate order-1 allocations even for
small allocations that could fit in a single page (in order to avoid
excessive fragmentation).

Maybe we should remove this warning entirely, but before making that
judgement, at least limit it to bigger allocations.

Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-24 12:16:49 -07:00
Dimitri Sivanich 364df0ebfb mm: fix handling of pagesets for downed cpus
After downing/upping a cpu, an attempt to set
/proc/sys/vm/percpu_pagelist_fraction results in an oops in
percpu_pagelist_fraction_sysctl_handler().

If a processor is downed then we need to set the pageset pointer back to
the boot pageset.

Updates of the high water marks should not access pagesets of unpopulated
zones (those pointer go to the boot pagesets which would be no longer
functional if their size would be increased beyond zero).

Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-23 12:50:05 -07:00
Johannes Weiner c277331d5f mm: page_alloc: clear PG_locked before checking flags on free
da456f1 "page allocator: do not disable interrupts in free_page_mlock()" moved
the PG_mlocked clearing after the flag sanity checking which makes mlocked
pages always trigger 'bad page'.  Fix this by clearing the bit up front.

Reported--and-debugged-by: Peter Chubb <peter.chubb@nicta.com.au>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Tested-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-20 16:08:22 -07:00
Benjamin Herrenschmidt dcce284a25 mm: Extend gfp masking to the page allocator
The page allocator also needs the masking of gfp flags during boot,
so this moves it out of slab/slub and uses it with the page allocator
as well.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-18 13:12:57 -07:00
Linus Torvalds 517d08699b Merge branch 'akpm'
* akpm: (182 commits)
  fbdev: bf54x-lq043fb: use kzalloc over kmalloc/memset
  fbdev: *bfin*: fix __dev{init,exit} markings
  fbdev: *bfin*: drop unnecessary calls to memset
  fbdev: bfin-t350mcqb-fb: drop unused local variables
  fbdev: blackfin has __raw I/O accessors, so use them in fb.h
  fbdev: s1d13xxxfb: add accelerated bitblt functions
  tcx: use standard fields for framebuffer physical address and length
  fbdev: add support for handoff from firmware to hw framebuffers
  intelfb: fix a bug when changing video timing
  fbdev: use framebuffer_release() for freeing fb_info structures
  radeon: P2G2CLK_ALWAYS_ONb tested twice, should 2nd be P2G2CLK_DAC_ALWAYS_ONb?
  s3c-fb: CPUFREQ frequency scaling support
  s3c-fb: fix resource releasing on error during probing
  carminefb: fix possible access beyond end of carmine_modedb[]
  acornfb: remove fb_mmap function
  mb862xxfb: use CONFIG_OF instead of CONFIG_PPC_OF
  mb862xxfb: restrict compliation of platform driver to PPC
  Samsung SoC Framebuffer driver: add Alpha Channel support
  atmel-lcdc: fix pixclock upper bound detection
  offb: use framebuffer_alloc() to allocate fb_info struct
  ...

Manually fix up conflicts due to kmemcheck in mm/slab.c
2009-06-16 19:50:13 -07:00
Mel Gorman fa5e084e43 vmscan: do not unconditionally treat zones that fail zone_reclaim() as full
On NUMA machines, the administrator can configure zone_reclaim_mode that
is a more targetted form of direct reclaim.  On machines with large NUMA
distances for example, a zone_reclaim_mode defaults to 1 meaning that
clean unmapped pages will be reclaimed if the zone watermarks are not
being met.  The problem is that zone_reclaim() failing at all means the
zone gets marked full.

This can cause situations where a zone is usable, but is being skipped
because it has been considered full.  Take a situation where a large tmpfs
mount is occuping a large percentage of memory overall.  The pages do not
get cleaned or reclaimed by zone_reclaim(), but the zone gets marked full
and the zonelist cache considers them not worth trying in the future.

This patch makes zone_reclaim() return more fine-grained information about
what occured when zone_reclaim() failued.  The zone only gets marked full
if it really is unreclaimable.  If it's a case that the scan did not occur
or if enough pages were not reclaimed with the limited reclaim_mode, then
the zone is simply skipped.

There is a side-effect to this patch.  Currently, if zone_reclaim()
successfully reclaimed SWAP_CLUSTER_MAX, an allocation attempt would go
ahead.  With this patch applied, zone watermarks are rechecked after
zone_reclaim() does some work.

This bug was introduced by commit 9276b1bc96
("memory page_alloc zonelist caching speedup") way back in 2.6.19 when the
zonelist_cache was introduced.  It was not intended that zone_reclaim()
aggressively consider the zone to be full when it failed as full direct
reclaim can still be an option.  Due to the age of the bug, it should be
considered a -stable candidate.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:45 -07:00
Yinghai Lu 73d60b7f74 page-allocator: clear N_HIGH_MEMORY map before we set it again
SRAT tables may contains nodes of very small size.  The arch code may
decide to not activate such a node.  However, currently the early boot
code sets N_HIGH_MEMORY for such nodes.  These nodes therefore seem to be
active although these nodes have no present pages.

For 64bit N_HIGH_MEMORY == N_NORMAL_MEMORY, so that works for 64 bit too

Signed-off-by: Yinghai Lu <Yinghai@kernel.org>
Tested-by: Jack Steiner <steiner@sgi.com>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:43 -07:00
David Rientjes 82553a937f oom: invoke oom killer for __GFP_NOFAIL
The oom killer must be invoked regardless of the order if the allocation
is __GFP_NOFAIL, otherwise it will loop forever when reclaim fails to free
some memory.

Cc: Nick Piggin <npiggin@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:43 -07:00
KOSAKI Motohiro 6837765963 mm: remove CONFIG_UNEVICTABLE_LRU config option
Currently, nobody wants to turn UNEVICTABLE_LRU off.  Thus this
configurability is unnecessary.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andi Kleen <andi@firstfloor.org>
Acked-by: Minchan Kim <minchan.kim@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:42 -07:00
Minchan Kim bce7394a3e page-allocator: reset wmark_min and inactive ratio of zone when hotplug happens
Solve two problems.

Whenever memory hotplug sucessfully happens, zone->present_pages
have to be changed.

1) Now memory hotplug calls setup_per_zone_wmark_min only when
   online_pages called, not offline_pages.

   It breaks balance.

2) If zone->present_pages is changed, we also have to change
   zone->inactive_ratio.  That's because inactive_ratio depends on
   zone->present_pages.

Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:42 -07:00
Minchan Kim 96cb4df5dd page-allocator: add inactive ratio calculation function of each zone
Factor the per-zone arithemetic inside setup_per_zone_inactive_ratio()'s
loop into a a separate function, calculate_zone_inactive_ratio().  This
function will be used in a later patch

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:42 -07:00
Minchan Kim bc75d33f0f page-allocator: clean up functions related to pages_min
Change the names of two functions. It doesn't affect behavior.

Presently, setup_per_zone_pages_min() changes low, high of zone as well as
min.  So a better name is setup_per_zone_wmarks().  That's because Mel
changed zone->pages_[hig/low/min] to zone->watermark array in "page
allocator: replace the watermark-related union in struct zone with a
watermark[] array".

 * setup_per_zone_pages_min => setup_per_zone_wmarks

Of course, we have to change init_per_zone_pages_min, too.  There are not
pages_min any more.

 * init_per_zone_pages_min => init_per_zone_wmark_min

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:41 -07:00
Rafael J. Wysocki 7f33d49a2e mm, PM/Freezer: Disable OOM killer when tasks are frozen
Currently, the following scenario appears to be possible in theory:

* Tasks are frozen for hibernation or suspend.
* Free pages are almost exhausted.
* Certain piece of code in the suspend code path attempts to allocate
  some memory using GFP_KERNEL and allocation order less than or
  equal to PAGE_ALLOC_COSTLY_ORDER.
* __alloc_pages_internal() cannot find a free page so it invokes the
  OOM killer.
* The OOM killer attempts to kill a task, but the task is frozen, so
  it doesn't die immediately.
* __alloc_pages_internal() jumps to 'restart', unsuccessfully tries
  to find a free page and invokes the OOM killer.
* No progress can be made.

Although it is now hard to trigger during hibernation due to the memory
shrinking carried out by the hibernation code, it is theoretically
possible to trigger during suspend after the memory shrinking has been
removed from that code path.  Moreover, since memory allocations are
going to be used for the hibernation memory shrinking, it will be even
more likely to happen during hibernation.

To prevent it from happening, introduce the oom_killer_disabled switch
that will cause __alloc_pages_internal() to fail in the situations in
which the OOM killer would have been called and make the freezer set
this switch after tasks have been successfully frozen.

[akpm@linux-foundation.org: be nicer to the namespace]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Fengguang Wu <fengguang.wu@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:40 -07:00
Andrew Morton dab48dab37 page-allocator: warn if __GFP_NOFAIL is used for a large allocation
__GFP_NOFAIL is a bad fiction.  Allocations _can_ fail, and callers should
detect and suitably handle this (and not by lamely moving the infinite
loop up to the caller level either).

Attempting to use __GFP_NOFAIL for a higher-order allocation is even
worse, so add a once-off runtime check for this to slap people around for
even thinking about trying it.

Cc: David Rientjes <rientjes@google.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:40 -07:00
Cyrill Gorcunov e9bb35df6f mm: setup_per_zone_inactive_ratio - fix comment and make it __init
The caller of setup_per_zone_inactive_ratio is an __init function.  There
is no need to keep the callee after it completed as well.  Also fix a
comment.

Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:39 -07:00
Cyrill Gorcunov 5c87eada68 mm: setup_per_zone_inactive_ratio - do not call for int_sqrt if not needed
int_sqrt() returns 0 if its argument is zero so call it if only needed.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:39 -07:00
Wu Fengguang 6e08a369ee vmscan: cleanup the scan batching code
The vmscan batching logic is twisting.  Move it into a standalone function
nr_scan_try_batch() and document it.  No behavior change.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:39 -07:00
Wu Fengguang 20a0307c03 mm: introduce PageHuge() for testing huge/gigantic pages
A series of patches to enhance the /proc/pagemap interface and to add a
userspace executable which can be used to present the pagemap data.

Export 10 more flags to end users (and more for kernel developers):

        11. KPF_MMAP            (pseudo flag) memory mapped page
        12. KPF_ANON            (pseudo flag) memory mapped page (anonymous)
        13. KPF_SWAPCACHE       page is in swap cache
        14. KPF_SWAPBACKED      page is swap/RAM backed
        15. KPF_COMPOUND_HEAD   (*)
        16. KPF_COMPOUND_TAIL   (*)
        17. KPF_HUGE		hugeTLB pages
        18. KPF_UNEVICTABLE     page is in the unevictable LRU list
        19. KPF_HWPOISON        hardware detected corruption
        20. KPF_NOPAGE          (pseudo flag) no page frame at the address

        (*) For compound pages, exporting _both_ head/tail info enables
            users to tell where a compound page starts/ends, and its order.

a simple demo of the page-types tool

# ./page-types -h
page-types [options]
            -r|--raw                  Raw mode, for kernel developers
            -a|--addr    addr-spec    Walk a range of pages
            -b|--bits    bits-spec    Walk pages with specified bits
            -l|--list                 Show page details in ranges
            -L|--list-each            Show page details one by one
            -N|--no-summary           Don't show summay info
            -h|--help                 Show this usage message
addr-spec:
            N                         one page at offset N (unit: pages)
            N+M                       pages range from N to N+M-1
            N,M                       pages range from N to M-1
            N,                        pages range from N to end
            ,M                        pages range from 0 to M
bits-spec:
            bit1,bit2                 (flags & (bit1|bit2)) != 0
            bit1,bit2=bit1            (flags & (bit1|bit2)) == bit1
            bit1,~bit2                (flags & (bit1|bit2)) == bit1
            =bit1,bit2                flags == (bit1|bit2)
bit-names:
          locked              error         referenced           uptodate
           dirty                lru             active               slab
       writeback            reclaim              buddy               mmap
       anonymous          swapcache         swapbacked      compound_head
   compound_tail               huge        unevictable           hwpoison
          nopage           reserved(r)         mlocked(r)    mappedtodisk(r)
         private(r)       private_2(r)   owner_private(r)            arch(r)
        uncached(r)       readahead(o)       slob_free(o)     slub_frozen(o)
      slub_debug(o)
                                   (r) raw mode bits  (o) overloaded bits

# ./page-types
             flags      page-count       MB  symbolic-flags                     long-symbolic-flags
0x0000000000000000          487369     1903  _________________________________
0x0000000000000014               5        0  __R_D____________________________  referenced,dirty
0x0000000000000020               1        0  _____l___________________________  lru
0x0000000000000024              34        0  __R__l___________________________  referenced,lru
0x0000000000000028            3838       14  ___U_l___________________________  uptodate,lru
0x0001000000000028              48        0  ___U_l_______________________I___  uptodate,lru,readahead
0x000000000000002c            6478       25  __RU_l___________________________  referenced,uptodate,lru
0x000100000000002c              47        0  __RU_l_______________________I___  referenced,uptodate,lru,readahead
0x0000000000000040            8344       32  ______A__________________________  active
0x0000000000000060               1        0  _____lA__________________________  lru,active
0x0000000000000068             348        1  ___U_lA__________________________  uptodate,lru,active
0x0001000000000068              12        0  ___U_lA______________________I___  uptodate,lru,active,readahead
0x000000000000006c             988        3  __RU_lA__________________________  referenced,uptodate,lru,active
0x000100000000006c              48        0  __RU_lA______________________I___  referenced,uptodate,lru,active,readahead
0x0000000000004078               1        0  ___UDlA_______b__________________  uptodate,dirty,lru,active,swapbacked
0x000000000000407c              34        0  __RUDlA_______b__________________  referenced,uptodate,dirty,lru,active,swapbacked
0x0000000000000400             503        1  __________B______________________  buddy
0x0000000000000804               1        0  __R________M_____________________  referenced,mmap
0x0000000000000828            1029        4  ___U_l_____M_____________________  uptodate,lru,mmap
0x0001000000000828              43        0  ___U_l_____M_________________I___  uptodate,lru,mmap,readahead
0x000000000000082c             382        1  __RU_l_____M_____________________  referenced,uptodate,lru,mmap
0x000100000000082c              12        0  __RU_l_____M_________________I___  referenced,uptodate,lru,mmap,readahead
0x0000000000000868             192        0  ___U_lA____M_____________________  uptodate,lru,active,mmap
0x0001000000000868              12        0  ___U_lA____M_________________I___  uptodate,lru,active,mmap,readahead
0x000000000000086c             800        3  __RU_lA____M_____________________  referenced,uptodate,lru,active,mmap
0x000100000000086c              31        0  __RU_lA____M_________________I___  referenced,uptodate,lru,active,mmap,readahead
0x0000000000004878               2        0  ___UDlA____M__b__________________  uptodate,dirty,lru,active,mmap,swapbacked
0x0000000000001000             492        1  ____________a____________________  anonymous
0x0000000000005808               4        0  ___U_______Ma_b__________________  uptodate,mmap,anonymous,swapbacked
0x0000000000005868            2839       11  ___U_lA____Ma_b__________________  uptodate,lru,active,mmap,anonymous,swapbacked
0x000000000000586c              30        0  __RU_lA____Ma_b__________________  referenced,uptodate,lru,active,mmap,anonymous,swapbacked
             total          513968     2007

# ./page-types -r
             flags      page-count       MB  symbolic-flags                     long-symbolic-flags
0x0000000000000000          468002     1828  _________________________________
0x0000000100000000           19102       74  _____________________r___________  reserved
0x0000000000008000              41        0  _______________H_________________  compound_head
0x0000000000010000             188        0  ________________T________________  compound_tail
0x0000000000008014               1        0  __R_D__________H_________________  referenced,dirty,compound_head
0x0000000000010014               4        0  __R_D___________T________________  referenced,dirty,compound_tail
0x0000000000000020               1        0  _____l___________________________  lru
0x0000000800000024              34        0  __R__l__________________P________  referenced,lru,private
0x0000000000000028            3794       14  ___U_l___________________________  uptodate,lru
0x0001000000000028              46        0  ___U_l_______________________I___  uptodate,lru,readahead
0x0000000400000028              44        0  ___U_l_________________d_________  uptodate,lru,mappedtodisk
0x0001000400000028               2        0  ___U_l_________________d_____I___  uptodate,lru,mappedtodisk,readahead
0x000000000000002c            6434       25  __RU_l___________________________  referenced,uptodate,lru
0x000100000000002c              47        0  __RU_l_______________________I___  referenced,uptodate,lru,readahead
0x000000040000002c              14        0  __RU_l_________________d_________  referenced,uptodate,lru,mappedtodisk
0x000000080000002c              30        0  __RU_l__________________P________  referenced,uptodate,lru,private
0x0000000800000040            8124       31  ______A_________________P________  active,private
0x0000000000000040             219        0  ______A__________________________  active
0x0000000800000060               1        0  _____lA_________________P________  lru,active,private
0x0000000000000068             322        1  ___U_lA__________________________  uptodate,lru,active
0x0001000000000068              12        0  ___U_lA______________________I___  uptodate,lru,active,readahead
0x0000000400000068              13        0  ___U_lA________________d_________  uptodate,lru,active,mappedtodisk
0x0000000800000068              12        0  ___U_lA_________________P________  uptodate,lru,active,private
0x000000000000006c             977        3  __RU_lA__________________________  referenced,uptodate,lru,active
0x000100000000006c              48        0  __RU_lA______________________I___  referenced,uptodate,lru,active,readahead
0x000000040000006c               5        0  __RU_lA________________d_________  referenced,uptodate,lru,active,mappedtodisk
0x000000080000006c               3        0  __RU_lA_________________P________  referenced,uptodate,lru,active,private
0x0000000c0000006c               3        0  __RU_lA________________dP________  referenced,uptodate,lru,active,mappedtodisk,private
0x0000000c00000068               1        0  ___U_lA________________dP________  uptodate,lru,active,mappedtodisk,private
0x0000000000004078               1        0  ___UDlA_______b__________________  uptodate,dirty,lru,active,swapbacked
0x000000000000407c              34        0  __RUDlA_______b__________________  referenced,uptodate,dirty,lru,active,swapbacked
0x0000000000000400             538        2  __________B______________________  buddy
0x0000000000000804               1        0  __R________M_____________________  referenced,mmap
0x0000000000000828            1029        4  ___U_l_____M_____________________  uptodate,lru,mmap
0x0001000000000828              43        0  ___U_l_____M_________________I___  uptodate,lru,mmap,readahead
0x000000000000082c             382        1  __RU_l_____M_____________________  referenced,uptodate,lru,mmap
0x000100000000082c              12        0  __RU_l_____M_________________I___  referenced,uptodate,lru,mmap,readahead
0x0000000000000868             192        0  ___U_lA____M_____________________  uptodate,lru,active,mmap
0x0001000000000868              12        0  ___U_lA____M_________________I___  uptodate,lru,active,mmap,readahead
0x000000000000086c             800        3  __RU_lA____M_____________________  referenced,uptodate,lru,active,mmap
0x000100000000086c              31        0  __RU_lA____M_________________I___  referenced,uptodate,lru,active,mmap,readahead
0x0000000000004878               2        0  ___UDlA____M__b__________________  uptodate,dirty,lru,active,mmap,swapbacked
0x0000000000001000             492        1  ____________a____________________  anonymous
0x0000000000005008               2        0  ___U________a_b__________________  uptodate,anonymous,swapbacked
0x0000000000005808               4        0  ___U_______Ma_b__________________  uptodate,mmap,anonymous,swapbacked
0x000000000000580c               1        0  __RU_______Ma_b__________________  referenced,uptodate,mmap,anonymous,swapbacked
0x0000000000005868            2839       11  ___U_lA____Ma_b__________________  uptodate,lru,active,mmap,anonymous,swapbacked
0x000000000000586c              29        0  __RU_lA____Ma_b__________________  referenced,uptodate,lru,active,mmap,anonymous,swapbacked
             total          513968     2007

# ./page-types --raw --list --no-summary --bits reserved
offset  count   flags
0       15      _____________________r___________
31      4       _____________________r___________
159     97      _____________________r___________
4096    2067    _____________________r___________
6752    2390    _____________________r___________
9355    3       _____________________r___________
9728    14526   _____________________r___________

This patch:

Introduce PageHuge(), which identifies huge/gigantic pages by their
dedicated compound destructor functions.

Also move prep_compound_gigantic_page() to hugetlb.c and make
__free_pages_ok() non-static.

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:36 -07:00
Mel Gorman a1dd268cf6 mm: use alloc_pages_exact() in alloc_large_system_hash() to avoid duplicated logic
alloc_large_system_hash() has logic for freeing pages at the end of an
excessively large power-of-two buffer that is a duplicate of what is in
alloc_pages_exact().  This patch converts alloc_large_system_hash() to use
alloc_pages_exact().

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:36 -07:00
Mel Gorman 72807a74c0 page allocator: sanity check order in the page allocator slow path
Callers may speculatively call different allocators in order of preference
trying to allocate a buffer of a given size.  The order needed to allocate
this may be larger than what the page allocator can normally handle.
While the allocator mostly does the right thing, it should not direct
reclaim or wakeup kswapd with a bogus order.  This patch sanity checks the
order in the slow path and returns NULL if it is too large.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:36 -07:00
KOSAKI Motohiro 092cead617 page allocator: move free_page_mlock() to page_alloc.c
Currently, free_page_mlock() is only called from page_alloc.c.  Thus, we
can move it to page_alloc.c.

Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:35 -07:00
Christoph Lameter 62bc62a873 page allocator: use a pre-calculated value instead of num_online_nodes() in fast paths
num_online_nodes() is called in a number of places but most often by the
page allocator when deciding whether the zonelist needs to be filtered
based on cpusets or the zonelist cache.  This is actually a heavy function
and touches a number of cache lines.

This patch stores the number of online nodes at boot time and updates the
value when nodes get onlined and offlined.  The value is then used in a
number of important paths in place of num_online_nodes().

[rientjes@google.com: do not override definition of node_set_online() with macro]
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:35 -07:00
Mel Gorman 974709bdb2 page allocator: get the pageblock migratetype without disabling interrupts
Local interrupts are disabled when freeing pages to the PCP list.  Part of
that free checks what the migratetype of the pageblock the page is in but
it checks this with interrupts disabled and interupts should never be
disabled longer than necessary.  This patch checks the pagetype with
interrupts enabled with the impact that it is possible a page is freed to
the wrong list when a pageblock changes type.  As that block is now
already considered mixed from an anti-fragmentation perspective, it's not
of vital importance.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:35 -07:00
Mel Gorman f2260e6b1f page allocator: update NR_FREE_PAGES only as necessary
When pages are being freed to the buddy allocator, the zone NR_FREE_PAGES
counter must be updated.  In the case of bulk per-cpu page freeing, it's
updated once per page.  This retouches cache lines more than necessary.
Update the counters one per per-cpu bulk free.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:35 -07:00
Mel Gorman 418589663d page allocator: use allocation flags as an index to the zone watermark
ALLOC_WMARK_MIN, ALLOC_WMARK_LOW and ALLOC_WMARK_HIGH determin whether
pages_min, pages_low or pages_high is used as the zone watermark when
allocating the pages.  Two branches in the allocator hotpath determine
which watermark to use.

This patch uses the flags as an array index into a watermark array that is
indexed with WMARK_* defines accessed via helpers.  All call sites that
use zone->pages_* are updated to use the helpers for accessing the values
and the array offsets for setting.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:35 -07:00
Nick Piggin a3af9c389a page allocator: do not check for compound pages during the page allocator sanity checks
A number of sanity checks are made on each page allocation and free
including that the page count is zero.  page_count() checks for compound
pages and checks the count of the head page if true.  However, in these
paths, we do not care if the page is compound or not as the count of each
tail page should also be zero.

This patch makes two changes to the use of page_count() in the free path.
It converts one check of page_count() to a VM_BUG_ON() as the count should
have been unconditionally checked earlier in the free path.  It also
avoids checking for compound pages.

[mel@csn.ul.ie: Wrote changelog]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:34 -07:00
Mel Gorman d395b73428 page allocator: do not setup zonelist cache when there is only one node
There is a zonelist cache which is used to track zones that are not in the
allowed cpuset or found to be recently full.  This is to reduce cache
footprint on large machines.  On smaller machines, it just incurs cost for
no gain.  This patch only uses the zonelist cache when there are NUMA
nodes.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:34 -07:00
Mel Gorman da456f14d2 page allocator: do not disable interrupts in free_page_mlock()
free_page_mlock() tests and clears PG_mlocked using locked versions of the
bit operations.  If set, it disables interrupts to update counters and
this happens on every page free even though interrupts are disabled very
shortly afterwards a second time.  This is wasteful.

This patch splits what free_page_mlock() does.  The bit check is still
made.  However, the update of counters is delayed until the interrupts are
disabled and the non-lock version for clearing the bit is used.  One
potential weirdness with this split is that the counters do not get
updated if the bad_page() check is triggered but a system showing bad
pages is getting screwed already.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:34 -07:00
Mel Gorman ed0ae21dc5 page allocator: do not call get_pageblock_migratetype() more than necessary
get_pageblock_migratetype() is potentially called twice for every page
free.  Once, when being freed to the pcp lists and once when being freed
back to buddy.  When freeing from the pcp lists, it is known what the
pageblock type was at the time of free so use it rather than rechecking.
In low memory situations under memory pressure, this might skew
anti-fragmentation slightly but the interference is minimal and decisions
that are fragmenting memory are being made anyway.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:34 -07:00
Mel Gorman 0ac3a4099b page allocator: inline __rmqueue_fallback()
__rmqueue_fallback() is in the slow path but has only one call site.
Because there is only one call-site, this function can then be inlined
without causing text bloat.  On an x86-based config, it made no difference
as the savings were padded out by NOP instructions.  Milage varies but
text will either decrease in size or remain static.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:34 -07:00
Mel Gorman 0a15c3e9f6 page allocator: inline buffered_rmqueue()
buffered_rmqueue() is in the fast path so inline it.  Because it only has
one call site, this function can then be inlined without causing text
bloat.  On an x86-based config, it made no difference as the savings were
padded out by NOP instructions.  Milage varies but text will either
decrease in size or remain static.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:34 -07:00
Mel Gorman 728ec980fb page allocator: inline __rmqueue_smallest()
Inline __rmqueue_smallest by altering flow very slightly so that there is
only one call site.  Because there is only one call-site, this function
can then be inlined without causing text bloat.  On an x86-based config,
this patch reduces text by 16 bytes.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:33 -07:00
Mel Gorman a56f57ff94 page allocator: remove a branch by assuming __GFP_HIGH == ALLOC_HIGH
Allocations that specify __GFP_HIGH get the ALLOC_HIGH flag.  If these
flags are equal to each other, we can eliminate a branch.

[akpm@linux-foundation.org: Suggested the hack]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:33 -07:00
Peter Zijlstra 341ce06f69 page allocator: calculate the alloc_flags for allocation only once
Factor out the mapping between GFP and alloc_flags only once.  Once
factored out, it only needs to be calculated once but some care must be
taken.

[neilb@suse.de says]
As the test:

-       if (((p->flags & PF_MEMALLOC) || unlikely(test_thread_flag(TIF_MEMDIE)))
-                       && !in_interrupt()) {
-               if (!(gfp_mask & __GFP_NOMEMALLOC)) {

has been replaced with a slightly weaker one:

+       if (alloc_flags & ALLOC_NO_WATERMARKS) {

Without care, this would allow recursion into the allocator via direct
reclaim.  This patch ensures we do not recurse when PF_MEMALLOC is set but
TF_MEMDIE callers are now allowed to directly reclaim where they would
have been prevented in the past.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Neil Brown <neilb@suse.de>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:33 -07:00
Mel Gorman 3dd2826698 page allocator: calculate the migratetype for allocation only once
GFP mask is converted into a migratetype when deciding which pagelist to
take a page from.  However, it is happening multiple times per allocation,
at least once per zone traversed.  Calculate it once.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:33 -07:00
Mel Gorman 5117f45d11 page allocator: calculate the preferred zone for allocation only once
get_page_from_freelist() can be called multiple times for an allocation.
Part of this calculates the preferred_zone which is the first usable zone
in the zonelist but the zone depends on the GFP flags specified at the
beginning of the allocation call.  This patch calculates preferred_zone
once.  It's safe to do this because if preferred_zone is NULL at the start
of the call, no amount of direct reclaim or other actions will change the
fact the allocation will fail.

[akpm@linux-foundation.org: remove (void) casts]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:33 -07:00
Mel Gorman 49255c619f page allocator: move check for disabled anti-fragmentation out of fastpath
On low-memory systems, anti-fragmentation gets disabled as there is
nothing it can do and it would just incur overhead shuffling pages between
lists constantly.  Currently the check is made in the free page fast path
for every page.  This patch moves it to a slow path.  On machines with low
memory, there will be small amount of additional overhead as pages get
shuffled between lists but it should quickly settle.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:33 -07:00
Mel Gorman 11e33f6a55 page allocator: break up the allocator entry point into fast and slow paths
The core of the page allocator is one giant function which allocates
memory on the stack and makes calculations that may not be needed for
every allocation.  This patch breaks up the allocator path into fast and
slow paths for clarity.  Note the slow paths are still inlined but the
entry is marked unlikely.  If they were not inlined, it actally increases
text size to generate the as there is only one call site.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:32 -07:00
Mel Gorman 7f82af9742 page allocator: check only once if the zonelist is suitable for the allocation
It is possible with __GFP_THISNODE that no zones are suitable.  This patch
makes sure the check is only made once.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:32 -07:00
Mel Gorman b3c466ce51 page allocator: do not sanity check order in the fast path
No user of the allocator API should be passing in an order >= MAX_ORDER
but we check for it on each and every allocation.  Delete this check and
make it a VM_BUG_ON check further down the call path.

[akpm@linux-foundation.org: s/VM_BUG_ON/WARN_ON_ONCE/]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:32 -07:00
Mel Gorman d239171e4f page allocator: replace __alloc_pages_internal() with __alloc_pages_nodemask()
The start of a large patch series to clean up and optimise the page
allocator.

The performance improvements are in a wide range depending on the exact
machine but the results I've seen so fair are approximately;

kernbench:	0	to	 0.12% (elapsed time)
		0.49%	to	 3.20% (sys time)
aim9:		-4%	to	30% (for page_test and brk_test)
tbench:		-1%	to	 4%
hackbench:	-2.5%	to	 3.45% (mostly within the noise though)
netperf-udp	-1.34%  to	 4.06% (varies between machines a bit)
netperf-tcp	-0.44%  to	 5.22% (varies between machines a bit)

I haven't sysbench figures at hand, but previously they were within the
-0.5% to 2% range.

On netperf, the client and server were bound to opposite number CPUs to
maximise the problems with cache line bouncing of the struct pages so I
expect different people to report different results for netperf depending
on their exact machine and how they ran the test (different machines, same
cpus client/server, shared cache but two threads client/server, different
socket client/server etc).

I also measured the vmlinux sizes for a single x86-based config with
CONFIG_DEBUG_INFO enabled but not CONFIG_DEBUG_VM.  The core of the
.config is based on the Debian Lenny kernel config so I expect it to be
reasonably typical.

This patch:

__alloc_pages_internal is the core page allocator function but essentially
it is an alias of __alloc_pages_nodemask.  Naming a publicly available and
exported function "internal" is also a big ugly.  This patch renames
__alloc_pages_internal() to __alloc_pages_nodemask() and deletes the old
nodemask function.

Warning - This patch renames an exported symbol.  No kernel driver is
affected by external drivers calling __alloc_pages_internal() should
change the call to __alloc_pages_nodemask() without any alteration of
parameters.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:32 -07:00
Hugh Dickins 6c0db4664b mm: alloc_large_system_hash check order
On an x86_64 with 4GB ram, tcp_init()'s call to alloc_large_system_hash(),
to allocate tcp_hashinfo.ehash, is now triggering an mmotm WARN_ON_ONCE on
order >= MAX_ORDER - it's hoping for order 11.  alloc_large_system_hash()
had better make its own check on the order.

Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: David Miller <davem@davemloft.net>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Eric Dumazet <dada1@cosmosbay.com>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:31 -07:00
Miao Xie 58568d2a82 cpuset,mm: update tasks' mems_allowed in time
Fix allocating page cache/slab object on the unallowed node when memory
spread is set by updating tasks' mems_allowed after its cpuset's mems is
changed.

In order to update tasks' mems_allowed in time, we must modify the code of
memory policy.  Because the memory policy is applied in the process's
context originally.  After applying this patch, one task directly
manipulates anothers mems_allowed, and we use alloc_lock in the
task_struct to protect mems_allowed and memory policy of the task.

But in the fast path, we didn't use lock to protect them, because adding a
lock may lead to performance regression.  But if we don't add a lock,the
task might see no nodes when changing cpuset's mems_allowed to some
non-overlapping set.  In order to avoid it, we set all new allowed nodes,
then clear newly disallowed ones.

[lee.schermerhorn@hp.com:
  The rework of mpol_new() to extract the adjusting of the node mask to
  apply cpuset and mpol flags "context" breaks set_mempolicy() and mbind()
  with MPOL_PREFERRED and a NULL nodemask--i.e., explicit local
  allocation.  Fix this by adding the check for MPOL_PREFERRED and empty
  node mask to mpol_new_mpolicy().

  Remove the now unneeded 'nodes = NULL' from mpol_new().

  Note that mpol_new_mempolicy() is always called with a non-NULL
  'nodes' parameter now that it has been removed from mpol_new().
  Therefore, we don't need to test nodes for NULL before testing it for
  'empty'.  However, just to be extra paranoid, add a VM_BUG_ON() to
  verify this assumption.]
[lee.schermerhorn@hp.com:

  I don't think the function name 'mpol_new_mempolicy' is descriptive
  enough to differentiate it from mpol_new().

  This function applies cpuset set context, usually constraining nodes
  to those allowed by the cpuset.  However, when the 'RELATIVE_NODES flag
  is set, it also translates the nodes.  So I settled on
  'mpol_set_nodemask()', because the comment block for mpol_new() mentions
  that we need to call this function to "set nodes".

  Some additional minor line length, whitespace and typo cleanup.]
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Paul Menage <menage@google.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-06-16 19:47:31 -07:00
Vegard Nossum b1eeab6768 kmemcheck: add hooks for the page allocator
This adds support for tracking the initializedness of memory that
was allocated with the page allocator. Highmem requests are not
tracked.

Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>

[build fix for !CONFIG_KMEMCHECK]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
2009-06-15 15:48:33 +02:00
Catalin Marinas dbb1f81ca6 kmemleak: Add kmemleak_alloc callback from alloc_large_system_hash
The alloc_large_system_hash function is called from various places in
the kernel and it contains pointers to other allocated structures. It
therefore needs to be traced by kmemleak.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-06-11 17:03:30 +01:00
Yinghai Lu 888a589f6b mm, x86: remove MEMORY_HOTPLUG_RESERVE related code
after:

 | commit b263295dbf
 | Author: Christoph Lameter <clameter@sgi.com>
 | Date:   Wed Jan 30 13:30:47 2008 +0100
 |
 |    x86: 64-bit, make sparsemem vmemmap the only memory model

we don't have MEMORY_HOTPLUG_RESERVE anymore.

Historically, x86-64 had an architecture-specific method for memory hotplug
whereby it scanned the SRAT for physical memory ranges that could be
potentially used for memory hot-add later. By reserving those ranges
without physical memory, the memmap would be allocated and left dormant
until needed. This depended on the DISCONTIG memory model which has been
removed so the code implementing HOTPLUG_RESERVE is now dead.

This patch removes the dead code used by MEMORY_HOTPLUG_RESERVE.

(Changelog authored by Mel.)

v2: updated changelog, and remove hotadd= in doc

[ Impact: remove dead code ]

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Reviewed-by: Mel Gorman <mel@csn.ul.ie>
Workflow-found-OK-by: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <4A0C4910.7090508@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-05-18 09:13:31 +02:00
David Howells 3a6be87fd1 nommu: clamp zone_batchsize() to 0 under NOMMU conditions
Clamp zone_batchsize() to 0 under NOMMU conditions to stop
free_hot_cold_page() from queueing and batching frees.

The problem is that under NOMMU conditions it is really important to be
able to allocate large contiguous chunks of memory, but when munmap() or
exit_mmap() releases big stretches of memory, return of these to the buddy
allocator can be deferred, and when it does finally happen, it can be in
small chunks.

Whilst the fragmentation this incurs isn't so much of a problem under MMU
conditions as userspace VM is glued together from individual pages with
the aid of the MMU, it is a real problem if there isn't an MMU.

By clamping the page freeing queue size to 0, pages are returned to the
allocator immediately, and the buddy detector is more likely to be able to
glue them together into large chunks immediately, and fragmentation is
less likely to occur.

By disabling batching of frees, and by turning off the trimming of excess
space during boot, Coldfire can manage to boot.

Reported-by: Lanttor Guo <lanttor.guo@freescale.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Lanttor Guo <lanttor.guo@freescale.com>
Cc: Greg Ungerer <gerg@snapgear.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-06 16:36:10 -07:00
David Howells 9155203a5d mm: use roundown_pow_of_two() in zone_batchsize()
Use roundown_pow_of_two(N) in zone_batchsize() rather than (1 <<
(fls(N)-1)) as they are equivalent, and with the former it is easier to
see what is going on.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Lanttor Guo <lanttor.guo@freescale.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-05-06 16:36:10 -07:00
Linus Torvalds 90975ef712 Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-cpumask
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-cpumask: (36 commits)
  cpumask: remove cpumask allocation from idle_balance, fix
  numa, cpumask: move numa_node_id default implementation to topology.h, fix
  cpumask: remove cpumask allocation from idle_balance
  x86: cpumask: x86 mmio-mod.c use cpumask_var_t for downed_cpus
  x86: cpumask: update 32-bit APM not to mug current->cpus_allowed
  x86: microcode: cleanup
  x86: cpumask: use work_on_cpu in arch/x86/kernel/microcode_core.c
  cpumask: fix CONFIG_CPUMASK_OFFSTACK=y cpu hotunplug crash
  numa, cpumask: move numa_node_id default implementation to topology.h
  cpumask: convert node_to_cpumask_map[] to cpumask_var_t
  cpumask: remove x86 cpumask_t uses.
  cpumask: use cpumask_var_t in uv_flush_tlb_others.
  cpumask: remove cpumask_t assignment from vector_allocation_domain()
  cpumask: make Xen use the new operators.
  cpumask: clean up summit's send_IPI functions
  cpumask: use new cpumask functions throughout x86
  x86: unify cpu_callin_mask/cpu_callout_mask/cpu_initialized_mask/cpu_sibling_setup_mask
  cpumask: convert struct cpuinfo_x86's llc_shared_map to cpumask_var_t
  cpumask: convert node_to_cpumask_map[] to cpumask_var_t
  x86: unify 32 and 64-bit node_to_cpumask_map
  ...
2009-04-05 10:33:07 -07:00
Linus Torvalds 811158b147 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (28 commits)
  trivial: Update my email address
  trivial: NULL noise: drivers/mtd/tests/mtd_*test.c
  trivial: NULL noise: drivers/media/dvb/frontends/drx397xD_fw.h
  trivial: Fix misspelling of "Celsius".
  trivial: remove unused variable 'path' in alloc_file()
  trivial: fix a pdlfush -> pdflush typo in comment
  trivial: jbd header comment typo fix for JBD_PARANOID_IOFAIL
  trivial: wusb: Storage class should be before const qualifier
  trivial: drivers/char/bsr.c: Storage class should be before const qualifier
  trivial: h8300: Storage class should be before const qualifier
  trivial: fix where cgroup documentation is not correctly referred to
  trivial: Give the right path in Documentation example
  trivial: MTD: remove EOL from MODULE_DESCRIPTION
  trivial: Fix typo in bio_split()'s documentation
  trivial: PWM: fix of #endif comment
  trivial: fix typos/grammar errors in Kconfig texts
  trivial: Fix misspelling of firmware
  trivial: cgroups: documentation typo and spelling corrections
  trivial: Update contact info for Jochen Hein
  trivial: fix typo "resgister" -> "register"
  ...
2009-04-03 15:24:35 -07:00
KAMEZAWA Hiroyuki 327c0e9686 vmscan: fix it to take care of nodemask
try_to_free_pages() is used for the direct reclaim of up to
SWAP_CLUSTER_MAX pages when watermarks are low.  The caller to
alloc_pages_nodemask() can specify a nodemask of nodes that are allowed to
be used but this is not passed to try_to_free_pages().  This can lead to
unnecessary reclaim of pages that are unusable by the caller and int the
worst case lead to allocation failure as progress was not been make where
it is needed.

This patch passes the nodemask used for alloc_pages_nodemask() to
try_to_free_pages().

Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:15 -07:00
KOSAKI Motohiro ee99c71c59 mm: introduce for_each_populated_zone() macro
Impact: cleanup

In almost cases, for_each_zone() is used with populated_zone().  It's
because almost function doesn't need memoryless node information.
Therefore, for_each_populated_zone() can help to make code simplify.

This patch has no functional change.

[akpm@linux-foundation.org: small cleanup]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01 08:59:11 -07:00
Rusty Russell 558f6ab910 Merge branch 'cpumask-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
Conflicts:

	arch/x86/include/asm/topology.h
	drivers/oprofile/buffer_sync.c
(Both cases: changed in Linus' tree, removed in Ingo's).
2009-03-31 13:33:50 +10:30
Linus Torvalds c4e1aa67ed Merge branch 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (33 commits)
  lockdep: fix deadlock in lockdep_trace_alloc
  lockdep: annotate reclaim context (__GFP_NOFS), fix SLOB
  lockdep: annotate reclaim context (__GFP_NOFS), fix
  lockdep: build fix for !PROVE_LOCKING
  lockstat: warn about disabled lock debugging
  lockdep: use stringify.h
  lockdep: simplify check_prev_add_irq()
  lockdep: get_user_chars() redo
  lockdep: simplify get_user_chars()
  lockdep: add comments to mark_lock_irq()
  lockdep: remove macro usage from mark_held_locks()
  lockdep: fully reduce mark_lock_irq()
  lockdep: merge the !_READ mark_lock_irq() helpers
  lockdep: merge the _READ mark_lock_irq() helpers
  lockdep: simplify mark_lock_irq() helpers #3
  lockdep: further simplify mark_lock_irq() helpers
  lockdep: simplify the mark_lock_irq() helpers
  lockdep: split up mark_lock_irq()
  lockdep: generate usage strings
  lockdep: generate the state bit definitions
  ...
2009-03-30 17:17:35 -07:00
Alexey Zaytsev e713a21d82 trivial: Fix dubious bitwise 'or' usage spotted by sparse.
It doesn't change the semantics, but it looks like
the logical 'or' was meant to be used here.

Signed-off-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-03-30 15:21:56 +02:00
Rusty Russell a70f730282 cpumask: replace node_to_cpumask with cpumask_of_node.
Impact: cleanup

node_to_cpumask (and the blecherous node_to_cpumask_ptr which
contained a declaration) are replaced now everyone implements
cpumask_of_node.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-03-13 14:49:46 +10:30
KAMEZAWA Hiroyuki cc2559bccc mm: fix memmap init for handling memory hole
Now, early_pfn_in_nid(PFN, NID) may returns false if PFN is a hole.
and memmap initialization was not done. This was a trouble for
sparc boot.

To fix this, the PFN should be initialized and marked as PG_reserved.
This patch changes early_pfn_in_nid() return true if PFN is a hole.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reported-by: David Miller <davem@davemlloft.net>
Tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-18 15:37:55 -08:00
KAMEZAWA Hiroyuki f2dbcfa738 mm: clean up for early_pfn_to_nid()
What's happening is that the assertion in mm/page_alloc.c:move_freepages()
is triggering:

	BUG_ON(page_zone(start_page) != page_zone(end_page));

Once I knew this is what was happening, I added some annotations:

	if (unlikely(page_zone(start_page) != page_zone(end_page))) {
		printk(KERN_ERR "move_freepages: Bogus zones: "
		       "start_page[%p] end_page[%p] zone[%p]\n",
		       start_page, end_page, zone);
		printk(KERN_ERR "move_freepages: "
		       "start_zone[%p] end_zone[%p]\n",
		       page_zone(start_page), page_zone(end_page));
		printk(KERN_ERR "move_freepages: "
		       "start_pfn[0x%lx] end_pfn[0x%lx]\n",
		       page_to_pfn(start_page), page_to_pfn(end_page));
		printk(KERN_ERR "move_freepages: "
		       "start_nid[%d] end_nid[%d]\n",
		       page_to_nid(start_page), page_to_nid(end_page));
 ...

And here's what I got:

	move_freepages: Bogus zones: start_page[2207d0000] end_page[2207dffc0] zone[fffff8103effcb00]
	move_freepages: start_zone[fffff8103effcb00] end_zone[fffff8003fffeb00]
	move_freepages: start_pfn[0x81f600] end_pfn[0x81f7ff]
	move_freepages: start_nid[1] end_nid[0]

My memory layout on this box is:

[    0.000000] Zone PFN ranges:
[    0.000000]   Normal   0x00000000 -> 0x0081ff5d
[    0.000000] Movable zone start PFN for each node
[    0.000000] early_node_map[8] active PFN ranges
[    0.000000]     0: 0x00000000 -> 0x00020000
[    0.000000]     1: 0x00800000 -> 0x0081f7ff
[    0.000000]     1: 0x0081f800 -> 0x0081fe50
[    0.000000]     1: 0x0081fed1 -> 0x0081fed8
[    0.000000]     1: 0x0081feda -> 0x0081fedb
[    0.000000]     1: 0x0081fedd -> 0x0081fee5
[    0.000000]     1: 0x0081fee7 -> 0x0081ff51
[    0.000000]     1: 0x0081ff59 -> 0x0081ff5d

So it's a block move in that 0x81f600-->0x81f7ff region which triggers
the problem.

This patch:

Declaration of early_pfn_to_nid() is scattered over per-arch include
files, and it seems it's complicated to know when the declaration is used.
 I think it makes fix-for-memmap-init not easy.

This patch moves all declaration to include/linux/mm.h

After this,
  if !CONFIG_NODES_POPULATES_NODE_MAP && !CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
     -> Use static definition in include/linux/mm.h
  else if !CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
     -> Use generic definition in mm/page_alloc.c
  else
     -> per-arch back end function will be called.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: David Miller <davem@davemlloft.net>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: <stable@kernel.org>		[2.6.25.x, 2.6.26.x, 2.6.27.x, 2.6.28.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-18 15:37:55 -08:00
Nick Piggin cf40bd16fd lockdep: annotate reclaim context (__GFP_NOFS)
Here is another version, with the incremental patch rolled up, and
added reclaim context annotation to kswapd, and allocation tracing
to slab allocators (which may only ever reach the page allocator
in rare cases, so it is good to put annotations here too).

Haven't tested this version as such, but it should be getting closer
to merge worthy ;)

--
After noticing some code in mm/filemap.c accidentally perform a __GFP_FS
allocation when it should not have been, I thought it might be a good idea to
try to catch this kind of thing with lockdep.

I coded up a little idea that seems to work. Unfortunately the system has to
actually be in __GFP_FS page reclaim, then take the lock, before it will mark
it. But at least that might still be some orders of magnitude more common
(and more debuggable) than an actual deadlock condition, so we have some
improvement I hope (the concept is no less complete than discovery of a lock's
interrupt contexts).

I guess we could even do the same thing with __GFP_IO (normal reclaim), and
even GFP_NOIO locks too... but filesystems will have the most locks and fiddly
code paths, so let's start there and see how it goes.

It *seems* to work. I did a quick test.

=================================
[ INFO: inconsistent lock state ]
2.6.28-rc6-00007-ged31348-dirty #26
---------------------------------
inconsistent {in-reclaim-W} -> {ov-reclaim-W} usage.
modprobe/8526 [HC0[0]:SC0[0]:HE1:SE1] takes:
 (testlock){--..}, at: [<ffffffffa0020055>] brd_init+0x55/0x216 [brd]
{in-reclaim-W} state was registered at:
  [<ffffffff80267bdb>] __lock_acquire+0x75b/0x1a60
  [<ffffffff80268f71>] lock_acquire+0x91/0xc0
  [<ffffffff8070f0e1>] mutex_lock_nested+0xb1/0x310
  [<ffffffffa002002b>] brd_init+0x2b/0x216 [brd]
  [<ffffffff8020903b>] _stext+0x3b/0x170
  [<ffffffff80272ebf>] sys_init_module+0xaf/0x1e0
  [<ffffffff8020c3fb>] system_call_fastpath+0x16/0x1b
  [<ffffffffffffffff>] 0xffffffffffffffff
irq event stamp: 3929
hardirqs last  enabled at (3929): [<ffffffff8070f2b5>] mutex_lock_nested+0x285/0x310
hardirqs last disabled at (3928): [<ffffffff8070f089>] mutex_lock_nested+0x59/0x310
softirqs last  enabled at (3732): [<ffffffff8061f623>] sk_filter+0x83/0xe0
softirqs last disabled at (3730): [<ffffffff8061f5b6>] sk_filter+0x16/0xe0

other info that might help us debug this:
1 lock held by modprobe/8526:
 #0:  (testlock){--..}, at: [<ffffffffa0020055>] brd_init+0x55/0x216 [brd]

stack backtrace:
Pid: 8526, comm: modprobe Not tainted 2.6.28-rc6-00007-ged31348-dirty #26
Call Trace:
 [<ffffffff80265483>] print_usage_bug+0x193/0x1d0
 [<ffffffff80266530>] mark_lock+0xaf0/0xca0
 [<ffffffff80266735>] mark_held_locks+0x55/0xc0
 [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
 [<ffffffff802667ca>] trace_reclaim_fs+0x2a/0x60
 [<ffffffff80285005>] __alloc_pages_internal+0x475/0x580
 [<ffffffff8070f29e>] ? mutex_lock_nested+0x26e/0x310
 [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
 [<ffffffffa002006a>] brd_init+0x6a/0x216 [brd]
 [<ffffffffa0020000>] ? brd_init+0x0/0x216 [brd]
 [<ffffffff8020903b>] _stext+0x3b/0x170
 [<ffffffff8070f8b9>] ? mutex_unlock+0x9/0x10
 [<ffffffff8070f83d>] ? __mutex_unlock_slowpath+0x10d/0x180
 [<ffffffff802669ec>] ? trace_hardirqs_on_caller+0x12c/0x190
 [<ffffffff80272ebf>] sys_init_module+0xaf/0x1e0
 [<ffffffff8020c3fb>] system_call_fastpath+0x16/0x1b

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-14 23:27:49 +01:00
KOSAKI Motohiro 6e9015716a mm: introduce zone_reclaim struct
Add zone_reclam_stat struct for later enhancement.

A later patch uses this.  This patch doesn't any behavior change (yet).

Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-08 08:31:07 -08:00
KOSAKI Motohiro 9f572e3f96 mm: remove CONFIG_OUT_OF_LINE_PFN_TO_PAGE
No architectures use CONFIG_OUT_OF_LINE_PFN_TO_PAGE - it can be removed.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:10 -08:00
Hugh Dickins 1e9e63650d badpage: KERN_ALERT BUG instead of KERN_EMERG
bad_page() and rmap Eeek messages have said KERN_EMERG for a few years,
which I've followed in print_bad_pte().  These are serious system errors,
on a par with BUGs, but they're not quite emergencies, and we do our best
to carry on: say KERN_ALERT "BUG: " like the x86 oops does.

And remove the "Trying to fix it up, but a reboot is needed" line: it's
not untrue, but I hope the KERN_ALERT "BUG: " conveys as much.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:08 -08:00
Hugh Dickins d936cf9b39 badpage: ratelimit print_bad_pte and bad_page
print_bad_pte() and bad_page() might each need ratelimiting - especially
for their dump_stacks, almost never of interest, yet not quite
dispensible.  Correlating corruption across neighbouring entries can be
very helpful, so allow a burst of 60 reports before keeping quiet for the
remainder of that minute (or allow a steady drip of one report per
second).

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:07 -08:00
Hugh Dickins 22b31eec63 badpage: vm_normal_page use print_bad_pte
print_bad_pte() is so far being called only when zap_pte_range() finds
negative page_mapcount, or there's a fault on a pte_file where it does not
belong.  That's weak coverage when we suspect pagetable corruption.

Originally, it was called when vm_normal_page() found an invalid pfn: but
pfn_valid is expensive on some architectures and configurations, so 2.6.24
put that under CONFIG_DEBUG_VM (which doesn't help in the field), then
2.6.26 replaced it by a VM_BUG_ON (likewise).

Reinstate the print_bad_pte() in vm_normal_page(), but use a cheaper test
than pfn_valid(): memmap_init_zone() (used in bootup and hotplug) keep a
__read_mostly note of the highest_memmap_pfn, vm_normal_page() then check
pfn against that.  We could call this pfn_plausible() or pfn_sane(), but I
doubt we'll need it elsewhere: of course it's not reliable, but gives much
stronger pagetable validation on many boxes.

Also use print_bad_pte() when the pte_special bit is found outside a
VM_PFNMAP or VM_MIXEDMAP area, instead of VM_BUG_ON.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:07 -08:00
Hugh Dickins 3dc147414c badpage: replace page_remove_rmap Eeek and BUG
Now that bad pages are kept out of circulation, there is no need for the
infamous page_remove_rmap() BUG() - once that page is freed, its negative
mapcount will issue a "Bad page state" message and the page won't be
freed.  Removing the BUG() allows more info, on subsequent pages, to be
gathered.

We do have more info about the page at this point than bad_page() can know
- notably, what the pmd is, which might pinpoint something like low 64kB
corruption - but page_remove_rmap() isn't given the address to find that.

In practice, there is only one call to page_remove_rmap() which has ever
reported anything, that from zap_pte_range() (usually on exit, sometimes
on munmap).  It has all the info, so remove page_remove_rmap()'s "Eeek"
message and leave it all to zap_pte_range().

mm/memory.c already has a hardly used print_bad_pte() function, showing
some of the appropriate info: extend it to show what we want for the rmap
case: pte info, page info (when there is a page) and vma info to compare.
zap_pte_range() already knows the pmd, but print_bad_pte() is easier to
use if it works that out for itself.

Some of this info is also shown in bad_page()'s "Bad page state" message.
Keep them separate, but adjust them to match each other as far as
possible.  Say "Bad page map" in print_bad_pte(), and add a TAINT_BAD_PAGE
there too.

print_bad_pte() show current->comm unconditionally (though it should get
repeated in the usually irrelevant stack trace): sorry, I misled Nick
Piggin to make it conditional on vm_mm == current->mm, but current->mm is
already NULL in the exit case.  Usually current->comm is good, though
exceptionally it may not be that of the mm (when "swapoff" for example).

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:07 -08:00
Hugh Dickins 8cc3b39221 badpage: keep any bad page out of circulation
Until now the bad_page() checkers have special-cased PageReserved, keeping
those pages out of circulation thereafter.  Now extend the special case to
all: we want to keep ANY page with bad state out of circulation - the
"free" page may well be in use by something.

Leave the bad state of those pages untouched, for examination by
debuggers; except for PageBuddy - leaving that set would risk bringing the
page back.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:07 -08:00
Hugh Dickins 79f4b7bf39 badpage: simplify page_alloc flag check+clear
Simplify the PAGE_FLAGS checking and clearing when freeing and allocating
a page: check the same flags as before when freeing, clear ALL the flags
(unless PageReserved) when freeing, check ALL flags off when allocating.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:07 -08:00
KOSAKI Motohiro efab818641 mm: make setup_per_zone_inactive_ratio() static
Sparse output following warning.

mm/page_alloc.c:4301:6: warning: symbol 'setup_per_zone_inactive_ratio' was not declared. Should it be static?

cleanup here.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:05 -08:00
Hugh Dickins b962716b45 mm: optimize get_scan_ratio for no swap
Rik suggests a simplified get_scan_ratio() for !CONFIG_SWAP.  Yes, the gcc
optimizer gives us that, when nr_swap_pages is #defined as 0L.  Move usual
declaration to swapfile.c: it never belonged in page_alloc.c.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Robin Holt <holt@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:04 -08:00
Julia Lawall 58a01a4572 mm/page_alloc.c: eliminate NULL test and memset after alloc_bootmem
As noted by Akinobu Mita in patch b1fceac2b9,
alloc_bootmem and related functions never return NULL and always return a
zeroed region of memory.  Thus a NULL test or memset after calls to these
functions is unnecessary.

This was fixed using the following semantic patch.
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression E;
statement S;
@@

E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\|alloc_bootmem_node\|alloc_bootmem_low_pages_node\|alloc_bootmem_pages_node\)(...)
... when != E
(
- BUG_ON (E == NULL);
|
- if (E == NULL) S
)

@@
expression E,E1;
@@

E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\|alloc_bootmem_node\|alloc_bootmem_low_pages_node\|alloc_bootmem_pages_node\)(...)
... when != E
- memset(E,0,E1);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:02 -08:00
Yinghai Lu 5594c8c813 mm: print out memmap number only if it is not zero
Don't print the size of the zone's memmap array if it does not have one.

Impact: cleanup

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-01-06 15:59:00 -08:00
David Rientjes e33c3b5e17 cpusets: update mems allowed in page allocator
If all allowable memory is unreclaimable, it is possible to loop forever
in the page allocator for ~__GFP_NORETRY allocations.

During this time, it is also possible for a task's cpuset to expand its
set of allowable nodes so that it now includes free memory.  The cached
copy of this set, current->mems_allowed, is stale, however, since there
has not been a subsequent call to cpuset_update_task_memory_state().

The cached copy of the set of allowable nodes is now updated in the page
allocator's slow path so the additional memory is available to
get_page_from_freelist().

[akpm@linux-foundation.org: add comment]
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Paul Menage <menage@google.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-12 17:17:16 -08:00
Andy Whitcroft 18229df5b6 hugetlb: pull gigantic page initialisation out of the default path
As we can determine exactly when a gigantic page is in use we can optimise
the common regular page cases by pulling out gigantic page initialisation
into its own function.  As gigantic pages are never released to buddy we
do not need a destructor.  This effectivly reverts the previous change to
the main buddy allocator.  It also adds a paranoid check to ensure we
never release gigantic pages from hugetlbfs to the main buddy.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Cc: Jon Tollefson <kniht@linux.vnet.ibm.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: <stable@kernel.org>		[2.6.27.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-11-06 15:41:18 -08:00
KAMEZAWA Hiroyuki 52d4b9ac0b memcg: allocate all page_cgroup at boot
Allocate all page_cgroup at boot and remove page_cgroup poitner from
struct page.  This patch adds an interface as

 struct page_cgroup *lookup_page_cgroup(struct page*)

All FLATMEM/DISCONTIGMEM/SPARSEMEM  and MEMORY_HOTPLUG is supported.

Remove page_cgroup pointer reduces the amount of memory by
 - 4 bytes per PAGE_SIZE.
 - 8 bytes per PAGE_SIZE
if memory controller is disabled. (even if configured.)

On usual 8GB x86-32 server, this saves 8MB of NORMAL_ZONE memory.
On my x86-64 server with 48GB of memory, this saves 96MB of memory.
I think this reduction makes sense.

By pre-allocation, kmalloc/kfree in charge/uncharge are removed.
This means
  - we're not necessary to be afraid of kmalloc faiulre.
    (this can happen because of gfp_mask type.)
  - we can avoid calling kmalloc/kfree.
  - we can avoid allocating tons of small objects which can be fragmented.
  - we can know what amount of memory will be used for this extra-lru handling.

I added printk message as

	"allocated %ld bytes of page_cgroup"
        "please try cgroup_disable=memory option if you don't want"

maybe enough informative for users.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:52:39 -07:00
Gerald Schaefer 1125b4e394 setup_per_zone_pages_min(): take zone->lock instead of zone->lru_lock
This replaces zone->lru_lock in setup_per_zone_pages_min() with zone->lock.
There seems to be no need for the lru_lock anymore, but there is a need for
zone->lock instead, because that function may call move_freepages() via
setup_zone_migrate_reserve().

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Tested-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:52:32 -07:00
Yinghai Lu d903ef9f38 mm: print out meminit for memmap
Improve debuggability of memory setup problems.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:52:32 -07:00
Lee Schermerhorn 985737cf2e mlock: count attempts to free mlocked page
Allow free of mlock()ed pages.  This shouldn't happen, but during
developement, it occasionally did.

This patch allows us to survive that condition, while keeping the
statistics and events correct for debug.

Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:52:31 -07:00
Nick Piggin b291f00039 mlock: mlocked pages are unevictable
Make sure that mlocked pages also live on the unevictable LRU, so kswapd
will not scan them over and over again.

This is achieved through various strategies:

1) add yet another page flag--PG_mlocked--to indicate that
   the page is locked for efficient testing in vmscan and,
   optionally, fault path.  This allows early culling of
   unevictable pages, preventing them from getting to
   page_referenced()/try_to_unmap().  Also allows separate
   accounting of mlock'd pages, as Nick's original patch
   did.

   Note:  Nick's original mlock patch used a PG_mlocked
   flag.  I had removed this in favor of the PG_unevictable
   flag + an mlock_count [new page struct member].  I
   restored the PG_mlocked flag to eliminate the new
   count field.

2) add the mlock/unevictable infrastructure to mm/mlock.c,
   with internal APIs in mm/internal.h.  This is a rework
   of Nick's original patch to these files, taking into
   account that mlocked pages are now kept on unevictable
   LRU list.

3) update vmscan.c:page_evictable() to check PageMlocked()
   and, if vma passed in, the vm_flags.  Note that the vma
   will only be passed in for new pages in the fault path;
   and then only if the "cull unevictable pages in fault
   path" patch is included.

4) add try_to_unlock() to rmap.c to walk a page's rmap and
   ClearPageMlocked() if no other vmas have it mlocked.
   Reuses as much of try_to_unmap() as possible.  This
   effectively replaces the use of one of the lru list links
   as an mlock count.  If this mechanism let's pages in mlocked
   vmas leak through w/o PG_mlocked set [I don't know that it
   does], we should catch them later in try_to_unmap().  One
   hopes this will be rare, as it will be relatively expensive.

Original mm/internal.h, mm/rmap.c and mm/mlock.c changes:
Signed-off-by: Nick Piggin <npiggin@suse.de>

splitlru: introduce __get_user_pages():

  New munlock processing need to GUP_FLAGS_IGNORE_VMA_PERMISSIONS.
  because current get_user_pages() can't grab PROT_NONE pages theresore it
  cause PROT_NONE pages can't munlock.

[akpm@linux-foundation.org: fix this for pagemap-pass-mm-into-pagewalkers.patch]
[akpm@linux-foundation.org: untangle patch interdependencies]
[akpm@linux-foundation.org: fix things after out-of-order merging]
[hugh@veritas.com: fix page-flags mess]
[lee.schermerhorn@hp.com: fix munlock page table walk - now requires 'mm']
[kosaki.motohiro@jp.fujitsu.com: build fix]
[kosaki.motohiro@jp.fujitsu.com: fix truncate race and sevaral comments]
[kosaki.motohiro@jp.fujitsu.com: splitlru: introduce __get_user_pages()]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Matt Mackall <mpm@selenic.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:52:30 -07:00
Lee Schermerhorn 7b854121eb Unevictable LRU Page Statistics
Report unevictable pages per zone and system wide.

Kosaki Motohiro added support for memory controller unevictable
statistics.

[riel@redhat.com: fix printk in show_free_areas()]
[akpm@linux-foundation.org: fix units in /proc/vmstats]
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Debugged-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:50:26 -07:00
Rik van Riel 556adecba1 vmscan: second chance replacement for anonymous pages
We avoid evicting and scanning anonymous pages for the most part, but
under some workloads we can end up with most of memory filled with
anonymous pages.  At that point, we suddenly need to clear the referenced
bits on all of memory, which can take ages on very large memory systems.

We can reduce the maximum number of pages that need to be scanned by not
taking the referenced state into account when deactivating an anonymous
page.  After all, every anonymous page starts out referenced, so why
check?

If an anonymous page gets referenced again before it reaches the end of
the inactive list, we move it back to the active list.

To keep the maximum amount of necessary work reasonable, we scale the
active to inactive ratio with the size of memory, using the formula
active:inactive ratio = sqrt(memory in GB * 10).

Kswapd CPU use now seems to scale by the amount of pageout bandwidth,
instead of by the amount of memory present in the system.

[kamezawa.hiroyu@jp.fujitsu.com: fix OOM with memcg]
[kamezawa.hiroyu@jp.fujitsu.com: memcg: lru scan fix]
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:50:25 -07:00
Rik van Riel 4f98a2fee8 vmscan: split LRU lists into anon & file sets
Split the LRU lists in two, one set for pages that are backed by real file
systems ("file") and one for pages that are backed by memory and swap
("anon").  The latter includes tmpfs.

The advantage of doing this is that the VM will not have to scan over lots
of anonymous pages (which we generally do not want to swap out), just to
find the page cache pages that it should evict.

This patch has the infrastructure and a basic policy to balance how much
we scan the anon lists and how much we scan the file lists.  The big
policy changes are in separate patches.

[lee.schermerhorn@hp.com: collect lru meminfo statistics from correct offset]
[kosaki.motohiro@jp.fujitsu.com: prevent incorrect oom under split_lru]
[kosaki.motohiro@jp.fujitsu.com: fix pagevec_move_tail() doesn't treat unevictable page]
[hugh@veritas.com: memcg swapbacked pages active]
[hugh@veritas.com: splitlru: BDI_CAP_SWAP_BACKED]
[akpm@linux-foundation.org: fix /proc/vmstat units]
[nishimura@mxp.nes.nec.co.jp: memcg: fix handling of shmem migration]
[kosaki.motohiro@jp.fujitsu.com: adjust Quicklists field of /proc/meminfo]
[kosaki.motohiro@jp.fujitsu.com: fix style issue of get_scan_ratio()]
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:50:25 -07:00
Rik van Riel b2e185384f define page_file_cache() function
Define page_file_cache() function to answer the question:
	is page backed by a file?

Originally part of Rik van Riel's split-lru patch.  Extracted to make
available for other, independent reclaim patches.

Moved inline function to linux/mm_inline.h where it will be needed by
subsequent "split LRU" and "noreclaim" patches.

Unfortunately this needs to use a page flag, since the PG_swapbacked state
needs to be preserved all the way to the point where the page is last
removed from the LRU.  Trying to derive the status from other info in the
page resulted in wrong VM statistics in earlier split VM patchsets.

The total number of page flags in use on a 32 bit machine after this patch
is 19.

[akpm@linux-foundation.org: fix up out-of-order merge fallout]
[hugh@veritas.com: splitlru: shmem_getpage SetPageSwapBacked sooner[
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: MinChan Kim <minchan.kim@gmail.com>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:50:25 -07:00
Christoph Lameter b69408e88b vmscan: Use an indexed array for LRU variables
Currently we are defining explicit variables for the inactive and active
list.  An indexed array can be more generic and avoid repeating similar
code in several places in the reclaim code.

We are saving a few bytes in terms of code size:

Before:

   text    data     bss     dec     hex filename
4097753  573120 4092484 8763357  85b7dd vmlinux

After:

   text    data     bss     dec     hex filename
4097729  573120 4092484 8763333  85b7c5 vmlinux

Having an easy way to add new lru lists may ease future work on the
reclaim code.

Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-20 08:50:25 -07:00
Andrew Morton db99100d2e mm/page_alloc.c:free_area_init_nodes() fix inappropriate use of enum
Local variable `i' is a) misleadingly-named for an `enum zone_type' and b)
used for indexing zones as well as nodes as well as node_maps.

Make it an `int'.

Reported-by: Frans Pop <elendil@planet.nl>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16 11:21:29 -07:00