Commit graph

5113 commits

Author SHA1 Message Date
Minchan Kim 5db8a73a8d mm/memory-failure.c: fix page isolated count mismatch
Pages isolated for migration are accounted with the vmstat counters
NR_ISOLATE_[ANON|FILE].  Callers of migrate_pages() are expected to
increment these counters when pages are isolated from the LRU.  Once the
pages have been migrated, they are put back on the LRU or freed and the
isolated count is decremented.

Memory failure is not properly accounting for pages it isolates causing
the NR_ISOLATED counters to be negative.  On SMP builds, this goes
unnoticed as negative counters are treated as 0 due to expected per-cpu
drift.  On UP builds, the counter is treated by too_many_isolated() as a
large value causing processes to enter D state during page reclaim or
compaction.  This patch accounts for pages isolated by memory failure
correctly.

[mel@csn.ul.ie: rewrote changelog]
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Acked-by: 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>
2011-06-15 20:04:01 -07:00
KAMEZAWA Hiroyuki fbc29a25e4 memcg: avoid percpu cached charge draining at softlimit
Based on Michal Hocko's comment.

We are not draining per cpu cached charges during soft limit reclaim
because background reclaim doesn't care about charges.  It tries to free
some memory and charges will not give any.

Cached charges might influence only selection of the biggest soft limit
offender but as the call is done only after the selection has been already
done it makes no change.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-15 20:04:01 -07:00
KAMEZAWA Hiroyuki 26fe616844 memcg: fix percpu cached charge draining frequency
For performance, memory cgroup caches some "charge" from res_counter into
per cpu cache.  This works well but because it's cache, it needs to be
flushed in some cases.  Typical cases are

   1. when someone hit limit.

   2. when rmdir() is called and need to charges to be 0.

But "1" has problem.

Recently, with large SMP machines, we see many kworker runs because of
flushing memcg's cache.  Bad things in implementation are that even if a
cpu contains a cache for memcg not related to a memcg which hits limit,
drain code is called.

This patch does
        A) check percpu cache contains a useful data or not.
        B) check other asynchronous percpu draining doesn't run.
        C) don't call local cpu callback.

(*)This patch avoid changing the calling condition with hard-limit.

When I run "cat 1Gfile > /dev/null" under 300M limit memcg,

[Before]
13767 kamezawa  20   0 98.6m  424  416 D 10.0  0.0   0:00.61 cat
   58 root      20   0     0    0    0 S  0.6  0.0   0:00.09 kworker/2:1
   60 root      20   0     0    0    0 S  0.6  0.0   0:00.08 kworker/4:1
    4 root      20   0     0    0    0 S  0.3  0.0   0:00.02 kworker/0:0
   57 root      20   0     0    0    0 S  0.3  0.0   0:00.05 kworker/1:1
   61 root      20   0     0    0    0 S  0.3  0.0   0:00.05 kworker/5:1
   62 root      20   0     0    0    0 S  0.3  0.0   0:00.05 kworker/6:1
   63 root      20   0     0    0    0 S  0.3  0.0   0:00.05 kworker/7:1

[After]
 2676 root      20   0 98.6m  416  416 D  9.3  0.0   0:00.87 cat
 2626 kamezawa  20   0 15192 1312  920 R  0.3  0.0   0:00.28 top
    1 root      20   0 19384 1496 1204 S  0.0  0.0   0:00.66 init
    2 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kthreadd
    3 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ksoftirqd/0
    4 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kworker/0:0

[akpm@linux-foundation.org: make percpu_charge_mutex static, tweak comments]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Tested-by: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-15 20:04:01 -07:00
KAMEZAWA Hiroyuki 7ae534d074 memcg: fix wrong check of noswap with softlimit
Hierarchical reclaim doesn't swap out if memsw and resource limits are
thye same (memsw_is_minimum == true) because we would hit mem+swap limit
anyway (during hard limit reclaim).

If it comes to the soft limit we shouldn't consider memsw_is_minimum at
all because it doesn't make much sense.  Either the soft limit is bellow
the hard limit and then we cannot hit mem+swap limit or the direct reclaim
takes a precedence.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-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>
2011-06-15 20:04:01 -07:00
KAMEZAWA Hiroyuki 37573e8c71 memcg: fix init_page_cgroup nid with sparsemem
Commit 21a3c96468 ("memcg: allocate memory cgroup structures in local
nodes") makes page_cgroup allocation as NUMA aware.  But that caused a
problem https://bugzilla.kernel.org/show_bug.cgi?id=36192.

The problem was getting a NID from invalid struct pages, which was not
initialized because it was out-of-node, out of [node_start_pfn,
node_end_pfn)

Now, with sparsemem, page_cgroup_init scans pfn from 0 to max_pfn.  But
this may scan a pfn which is not on any node and can access memmap which
is not initialized.

This makes page_cgroup_init() for SPARSEMEM node aware and remove a code
to get nid from page->flags.  (Then, we'll use valid NID always.)

[akpm@linux-foundation.org: try to fix up comments]
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>
2011-06-15 20:04:01 -07:00
KAMEZAWA Hiroyuki 8957712710 mm: memory.numa_stat: fix file permission
Commit 406eb0c9ba ("memcg: add memory.numastat api for numa
statistics") adds memory.numa_stat file for memory cgroup.  But the file
permissions are wrong.

  [kamezawa@bluextal linux-2.6]$ ls -l /cgroup/memory/A/memory.numa_stat
  ---------- 1 root root 0 Jun  9 18:36 /cgroup/memory/A/memory.numa_stat

This patch fixes the permission as

  [root@bluextal kamezawa]# ls -l /cgroup/memory/A/memory.numa_stat
  -r--r--r-- 1 root root 0 Jun 10 16:49 /cgroup/memory/A/memory.numa_stat

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-15 20:04:01 -07:00
Rafael Aquini b0320c7b7d mm: fix negative commitlimit when gigantic hugepages are allocated
When 1GB hugepages are allocated on a system, free(1) reports less
available memory than what really is installed in the box.  Also, if the
total size of hugepages allocated on a system is over half of the total
memory size, CommitLimit becomes a negative number.

The problem is that gigantic hugepages (order > MAX_ORDER) can only be
allocated at boot with bootmem, thus its frames are not accounted to
'totalram_pages'.  However, they are accounted to hugetlb_total_pages()

What happens to turn CommitLimit into a negative number is this
calculation, in fs/proc/meminfo.c:

        allowed = ((totalram_pages - hugetlb_total_pages())
                * sysctl_overcommit_ratio / 100) + total_swap_pages;

A similar calculation occurs in __vm_enough_memory() in mm/mmap.c.

Also, every vm statistic which depends on 'totalram_pages' will render
confusing values, as if system were 'missing' some part of its memory.

Impact of this bug:

When gigantic hugepages are allocated and sysctl_overcommit_memory ==
OVERCOMMIT_NEVER.  In a such situation, __vm_enough_memory() goes through
the mentioned 'allowed' calculation and might end up mistakenly returning
-ENOMEM, thus forcing the system to start reclaiming pages earlier than it
would be ususal, and this could cause detrimental impact to overall
system's performance, depending on the workload.

Besides the aforementioned scenario, I can only think of this causing
annoyances with memory reports from /proc/meminfo and free(1).

[akpm@linux-foundation.org: standardize comment layout]
Reported-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Rafael Aquini <aquini@linux.com>
Acked-by: Russ Anderson <rja@sgi.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-15 20:04:01 -07:00
KAMEZAWA Hiroyuki 959ecc48fc mm/memory_hotplug.c: fix building of node hotplug zonelist
During memory hotplug we refresh zonelists when we online a page in a new
zone.  It means that the node's zonelist is not initialized until pages
are onlined.  So for example, "nid" passed by MEM_GOING_ONLINE notifier
will point to NODE_DATA(nid) which has no zone fallback list.  Moreover,
if we hot-add cpu-only nodes, alloc_pages() will do no fallback.

This patch makes a zonelist when a new pgdata is available.

Note: in production, at fujitsu, memory should be onlined before cpu
      and our server didn't have any memory-less nodes and had no problems.

      But recent changes in MEM_GOING_ONLINE+page_cgroup
      will access not initialized zonelist of node.
      Anyway, there are memory-less node and we need some care.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: 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>
2011-06-15 20:04:01 -07:00
Michal Hocko 3957c7768e mm: compaction: fix special case -1 order checks
Commit 56de7263fc ("mm: compaction: direct compact when a high-order
allocation fails") introduced a check for cc->order == -1 in
compact_finished.  We should continue compacting in that case because
the request came from userspace and there is no particular order to
compact for.  Similar check has been added by 82478fb7 (mm: compaction:
prevent division-by-zero during user-requested compaction) for
compaction_suitable.

The check is, however, done after zone_watermark_ok which uses order as a
right hand argument for shifts.  Not only watermark check is pointless if
we can break out without it but it also uses 1 << -1 which is not well
defined (at least from C standard).  Let's move the -1 check above
zone_watermark_ok.

[minchan.kim@gmail.com> - caught compaction_suitable]
Signed-off-by: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hioryu@jp.fujitsu.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-15 20:04:00 -07:00
Steven Rostedt 5f1a19070b mm: fix wrong kunmap_atomic() pointer
Running a ktest.pl test, I hit the following bug on x86_32:

  ------------[ cut here ]------------
  WARNING: at arch/x86/mm/highmem_32.c:81 __kunmap_atomic+0x64/0xc1()
   Hardware name:
  Modules linked in:
  Pid: 93, comm: sh Not tainted 2.6.39-test+ #1
  Call Trace:
   [<c04450da>] warn_slowpath_common+0x7c/0x91
   [<c042f5df>] ? __kunmap_atomic+0x64/0xc1
   [<c042f5df>] ? __kunmap_atomic+0x64/0xc1^M
   [<c0445111>] warn_slowpath_null+0x22/0x24
   [<c042f5df>] __kunmap_atomic+0x64/0xc1
   [<c04d4a22>] unmap_vmas+0x43a/0x4e0
   [<c04d9065>] exit_mmap+0x91/0xd2
   [<c0443057>] mmput+0x43/0xad
   [<c0448358>] exit_mm+0x111/0x119
   [<c044855f>] do_exit+0x1ff/0x5fa
   [<c0454ea2>] ? set_current_blocked+0x3c/0x40
   [<c0454f24>] ? sigprocmask+0x7e/0x8e
   [<c0448b55>] do_group_exit+0x65/0x88
   [<c0448b90>] sys_exit_group+0x18/0x1c
   [<c0c3915f>] sysenter_do_call+0x12/0x38
  ---[ end trace 8055f74ea3c0eb62 ]---

Running a ktest.pl git bisect, found the culprit: commit e303297e6c
("mm: extended batches for generic mmu_gather")

But although this was the commit triggering the bug, it was not the one
originally responsible for the bug.  That was commit d16dfc550f ("mm:
mmu_gather rework").

The code in zap_pte_range() has something that looks like the following:

	pte =  pte_offset_map_lock(mm, pmd, addr, &ptl);
	do {
		[...]
	} while (pte++, addr += PAGE_SIZE, addr != end);
	pte_unmap_unlock(pte - 1, ptl);

The pte starts off pointing at the first element in the page table
directory that was returned by the pte_offset_map_lock().  When it's done
with the page, pte will be pointing to anything between the next entry and
the first entry of the next page inclusive.  By doing a pte - 1, this puts
the pte back onto the original page, which is all that pte_unmap_unlock()
needs.

In most archs (64 bit), this is not an issue as the pte is ignored in the
pte_unmap_unlock().  But on 32 bit archs, where things may be kmapped, it
is essential that the pte passed to pte_unmap_unlock() resides on the same
page that was given by pte_offest_map_lock().

The problem came in d16dfc55 ("mm: mmu_gather rework") where it introduced
a "break;" from the while loop.  This alone did not seem to easily trigger
the bug.  But the modifications made by e303297e6 caused that "break;" to
be hit on the first iteration, before the pte++.

The pte not being incremented will now cause pte_unmap_unlock(pte - 1) to
be pointing to the previous page.  This will cause the wrong page to be
unmapped, and also trigger the warning above.

The simple solution is to just save the pointer given by
pte_offset_map_lock() and use it in the unlock.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Hugh Dickins <hughd@google.com>
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>
2011-06-15 20:04:00 -07:00
KOSAKI Motohiro d7911ef30c vmscan: implement swap token priority aging
While testing for memcg aware swap token, I observed a swap token was
often grabbed an intermittent running process (eg init, auditd) and they
never release a token.

Why?

Some processes (eg init, auditd, audispd) wake up when a process exiting.
And swap token can be get first page-in process when a process exiting
makes no swap token owner.  Thus such above intermittent running process
often get a token.

And currently, swap token priority is only decreased at page fault path.
Then, if the process sleep immediately after to grab swap token, the swap
token priority never be decreased.  That's obviously undesirable.

This patch implement very poor (and lightweight) priority aging.  It only
be affect to the above corner case and doesn't change swap tendency
workload performance (eg multi process qsbench load)

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-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>
2011-06-15 20:03:59 -07:00
KOSAKI Motohiro 83cd81a343 vmscan: implement swap token trace
This is useful for observing swap token activity.

example output:

             zsh-1845  [000]   598.962716: update_swap_token_priority:
mm=ffff88015eaf7700 old_prio=1 new_prio=0
          memtoy-1830  [001]   602.033900: update_swap_token_priority:
mm=ffff880037a45880 old_prio=947 new_prio=949
          memtoy-1830  [000]   602.041509: update_swap_token_priority:
mm=ffff880037a45880 old_prio=949 new_prio=951
          memtoy-1830  [000]   602.051959: update_swap_token_priority:
mm=ffff880037a45880 old_prio=951 new_prio=953
          memtoy-1830  [000]   602.052188: update_swap_token_priority:
mm=ffff880037a45880 old_prio=953 new_prio=955
          memtoy-1830  [001]   602.427184: put_swap_token:
token_mm=ffff880037a45880
             zsh-1789  [000]   602.427281: replace_swap_token:
old_token_mm=          (null) old_prio=0 new_token_mm=ffff88015eaf7018
new_prio=2
             zsh-1789  [001]   602.433456: update_swap_token_priority:
mm=ffff88015eaf7018 old_prio=2 new_prio=4
             zsh-1789  [000]   602.437613: update_swap_token_priority:
mm=ffff88015eaf7018 old_prio=4 new_prio=6
             zsh-1789  [000]   602.443924: update_swap_token_priority:
mm=ffff88015eaf7018 old_prio=6 new_prio=8
             zsh-1789  [000]   602.451873: update_swap_token_priority:
mm=ffff88015eaf7018 old_prio=8 new_prio=10
             zsh-1789  [001]   602.462639: update_swap_token_priority:
mm=ffff88015eaf7018 old_prio=10 new_prio=12

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: Rik van Riel<riel@redhat.com>
Reviewed-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>
2011-06-15 20:03:59 -07:00
KOSAKI Motohiro a433658c30 vmscan,memcg: memcg aware swap token
Currently, memcg reclaim can disable swap token even if the swap token mm
doesn't belong in its memory cgroup.  It's slightly risky.  If an admin
creates very small mem-cgroup and silly guy runs contentious heavy memory
pressure workload, every tasks are going to lose swap token and then
system may become unresponsive.  That's bad.

This patch adds 'memcg' parameter into disable_swap_token().  and if the
parameter doesn't match swap token, VM doesn't disable it.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-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>
2011-06-15 20:03:59 -07:00
Randy Dunlap 0164f69d0c mm/memory.c: fix kernel-doc notation
Fix new kernel-doc warnings in mm/memory.c:

  Warning(mm/memory.c:1327): No description found for parameter 'tlb'
  Warning(mm/memory.c:1327): Excess function parameter 'tlbp' description in 'unmap_vmas'

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>
2011-06-15 20:03:59 -07:00
Andrea Arcangeli f300ea4997 mm: remove khugepaged double thp vmstat update with CONFIG_NUMA=n
Johannes noticed the vmstat update is already taken care of by
khugepaged_alloc_hugepage() internally.  The only places that are required
to update the vmstat are the callers of alloc_hugepage (callers of
khugepaged_alloc_hugepage aren't).

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reported-by: Johannes Weiner <jweiner@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Johannes Weiner <jweiner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-15 20:03:58 -07:00
Linus Torvalds 40779859de Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  SLAB: Record actual last user of freed objects.
  slub: always align cpu_slab to honor cmpxchg_double requirement
2011-06-13 13:00:53 -07:00
Linus Torvalds 8397345172 Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  vfs: make unlink() and rmdir() return ENOENT in preference to EROFS
  lmLogOpen() broken failure exit
  usb: remove bad dput after dentry_unhash
  more conservative S_NOSEC handling
2011-06-07 18:36:59 -07:00
Hugh Dickins e0dcd8a05b mm: fix ENOSPC returned by handle_mm_fault()
Al Viro observes that in the hugetlb case, handle_mm_fault() may return
a value of the kind ENOSPC when its caller is expecting a value of the
kind VM_FAULT_SIGBUS: fix alloc_huge_page()'s failure returns.

Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-06 18:00:27 +09:00
Al Viro 9e1f1de02c more conservative S_NOSEC handling
Caching "we have already removed suid/caps" was overenthusiastic as merged.
On network filesystems we might have had suid/caps set on another client,
silently picked by this client on revalidate, all of that *without* clearing
the S_NOSEC flag.

AFAICS, the only reasonably sane way to deal with that is
	* new superblock flag; unless set, S_NOSEC is not going to be set.
	* local block filesystems set it in their ->mount() (more accurately,
mount_bdev() does, so does btrfs ->mount(), users of mount_bdev() other than
local block ones clear it)
	* if any network filesystem (or a cluster one) wants to use S_NOSEC,
it'll need to set MS_NOSEC in sb->s_flags *AND* take care to clear S_NOSEC when
inode attribute changes are picked from other clients.

It's not an earth-shattering hole (anybody that can set suid on another client
will almost certainly be able to write to the file before doing that anyway),
but it's a bug that needs fixing.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-06-03 18:24:58 -04:00
Suleiman Souhlal a947eb95ea SLAB: Record actual last user of freed objects.
Currently, when using CONFIG_DEBUG_SLAB, we put in kfree() or
kmem_cache_free() as the last user of free objects, which is not
very useful, so change it to the caller of those functions instead.

Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Suleiman Souhlal <suleiman@google.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-06-03 19:33:50 +03:00
Chris Metcalf d4d84fef6d slub: always align cpu_slab to honor cmpxchg_double requirement
On an architecture without CMPXCHG_LOCAL but with DEBUG_VM enabled,
the VM_BUG_ON() in __pcpu_double_call_return_bool() will cause an early
panic during boot unless we always align cpu_slab properly.

In principle we could remove the alignment-testing VM_BUG_ON() for
architectures that don't have CMPXCHG_LOCAL, but leaving it in means
that new code will tend not to break x86 even if it is introduced
on another platform, and it's low cost to require alignment.

Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-06-03 19:33:49 +03:00
Linus Torvalds 1fa7b6a29c Revert "mm: fail GFP_DMA allocations when ZONE_DMA is not configured"
This reverts commit a197b59ae6.

As rmk says:
 "Commit a197b59ae6 (mm: fail GFP_DMA allocations when ZONE_DMA is not
  configured) is causing regressions on ARM with various drivers which
  use GFP_DMA.

  The behaviour up until now has been to silently ignore that flag when
  CONFIG_ZONE_DMA is not enabled, and to allocate from the normal zone.
  However, as a result of the above commit, such allocations now fail
  which causes drivers to fail.  These are regressions compared to the
  previous kernel version."

so just revert it.

Requested-by: Russell King <linux@arm.linux.org.uk>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-02 06:11:24 +09:00
Peter Zijlstra bc658c9603 mm, rmap: Add yet more comments to page_get_anon_vma/page_lock_anon_vma
Inspired by an analysis from Hugh on why again all this doesn't explode
in our face.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-29 09:25:48 -07:00
Hugh Dickins eee0f252c6 mm: fix page_lock_anon_vma leaving mutex locked
On one machine I've been getting hangs, a page fault's anon_vma_prepare()
waiting in anon_vma_lock(), other processes waiting for that page's lock.

This is a replay of last year's f18194275c "mm: fix hang on
anon_vma->root->lock".

The new page_lock_anon_vma() places too much faith in its refcount: when
it has acquired the mutex_trylock(), it's possible that a racing task in
anon_vma_alloc() has just reallocated the struct anon_vma, set refcount
to 1, and is about to reset its anon_vma->root.

Fix this by saving anon_vma->root, and relying on the usual page_mapped()
check instead of a refcount check: if page is still mapped, the anon_vma
is still ours; if page is not still mapped, we're no longer interested.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-28 16:55:32 -07:00
Hugh Dickins 5dbe0af47f mm: fix kernel BUG at mm/rmap.c:1017!
I've hit the "address >= vma->vm_end" check in do_page_add_anon_rmap()
just once.  The stack showed khugepaged allocation trying to compact
pages: the call to page_add_anon_rmap() coming from remove_migration_pte().

That path holds anon_vma lock, but does not hold mmap_sem: it can
therefore race with a split_vma(), and in commit 5f70b962cc "mmap:
avoid unnecessary anon_vma lock" we just took away the anon_vma lock
protection when adjusting vma->vm_end.

I don't think that particular BUG_ON ever caught anything interesting,
so better replace it by a comment, than reinstate the anon_vma locking.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-28 16:09:26 -07:00
Hugh Dickins 826267cf1e tmpfs: fix race between truncate and writepage
While running fsx on tmpfs with a memhog then swapoff, swapoff was hanging
(interruptibly), repeatedly failing to locate the owner of a 0xff entry in
the swap_map.

Although shmem_writepage() does abandon when it sees incoming page index
is beyond eof, there was still a window in which shmem_truncate_range()
could come in between writepage's dropping lock and updating swap_map,
find the half-completed swap_map entry, and in trying to free it,
leave it in a state that swap_shmem_alloc() could not correct.

Arguably a bug in __swap_duplicate()'s and swap_entry_free()'s handling
of the different cases, but easiest to fix by moving swap_shmem_alloc()
under cover of the lock.

More interesting than the bug: it's been there since 2.6.33, why could
I not see it with earlier kernels?  The mmotm of two weeks ago seems to
have some magic for generating races, this is just one of three I found.

With yesterday's git I first saw this in mainline, bisected in search of
that magic, but the easy reproducibility evaporated.  Oh well, fix the bug.

Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-28 16:09:26 -07:00
Linus Torvalds 36947a7682 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (36 commits)
  Cache xattr security drop check for write v2
  fs: block_page_mkwrite should wait for writeback to finish
  mm: Wait for writeback when grabbing pages to begin a write
  configfs: remove unnecessary dentry_unhash on rmdir, dir rename
  fat: remove unnecessary dentry_unhash on rmdir, dir rename
  hpfs: remove unnecessary dentry_unhash on rmdir, dir rename
  minix: remove unnecessary dentry_unhash on rmdir, dir rename
  fuse: remove unnecessary dentry_unhash on rmdir, dir rename
  coda: remove unnecessary dentry_unhash on rmdir, dir rename
  afs: remove unnecessary dentry_unhash on rmdir, dir rename
  affs: remove unnecessary dentry_unhash on rmdir, dir rename
  9p: remove unnecessary dentry_unhash on rmdir, dir rename
  ncpfs: fix rename over directory with dangling references
  ncpfs: document dentry_unhash usage
  ecryptfs: remove unnecessary dentry_unhash on rmdir, dir rename
  hostfs: remove unnecessary dentry_unhash on rmdir, dir rename
  hfsplus: remove unnecessary dentry_unhash on rmdir, dir rename
  hfs: remove unnecessary dentry_unhash on rmdir, dir rename
  omfs: remove unnecessary dentry_unhash on rmdir, dir rneame
  udf: remove unnecessary dentry_unhash from rmdir, dir rename
  ...
2011-05-28 13:03:41 -07:00
Linus Torvalds c4a227d89f Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (25 commits)
  perf: Fix SIGIO handling
  perf top: Don't stop if no kernel symtab is found
  perf top: Handle kptr_restrict
  perf top: Remove unused macro
  perf events: initialize fd array to -1 instead of 0
  perf tools: Make sure kptr_restrict warnings fit 80 col terms
  perf tools: Fix build on older systems
  perf symbols: Handle /proc/sys/kernel/kptr_restrict
  perf: Remove duplicate headers
  ftrace: Add internal recursive checks
  tracing: Update btrfs's tracepoints to use u64 interface
  tracing: Add __print_symbolic_u64 to avoid warnings on 32bit machine
  ftrace: Set ops->flag to enabled even on static function tracing
  tracing: Have event with function tracer check error return
  ftrace: Have ftrace_startup() return failure code
  jump_label: Check entries limit in __jump_label_update
  ftrace/recordmcount: Avoid STT_FUNC symbols as base on ARM
  scripts/tags.sh: Add magic for trace-events for etags too
  scripts/tags.sh: Fix ctags for DEFINE_EVENT()
  x86/ftrace: Fix compiler warning in ftrace.c
  ...
2011-05-28 12:55:55 -07:00
Andi Kleen 69b4573296 Cache xattr security drop check for write v2
Some recent benchmarking on btrfs showed that a major scaling bottleneck
on large systems on btrfs is currently the xattr lookup on every write.

Why xattr lookup on every write I hear you ask?

write wants to drop suid and security related xattrs that could set o
capabilities for executables.  To do that it currently looks up
security.capability on EVERY write (even for non executables) to decide
whether to drop it or not.

In btrfs this causes an additional tree walk, hitting some per file system
locks and quite bad scalability. In a simple read workload on a 8S
system I saw over 90% CPU time in spinlocks related to that.

Chris Mason tells me this is also a problem in ext4, where it hits
the global mbcache lock.

This patch adds a simple per inode to avoid this problem.  We only
do the lookup once per file and then if there is no xattr cache
the decision. All xattr changes clear the flag.

I also used the same flag to avoid the suid check, although
that one is pretty cheap.

A file system can also set this flag when it creates the inode,
if it has a cheap way to do so.  This is done for some common file systems
in followon patches.

With this patch a major part of the lock contention disappears
for btrfs. Some testing on smaller systems didn't show significant
performance changes, but at least it helps the larger systems
and is generally more efficient.

v2: Rename is_sgid. add file system helper.
Cc: chris.mason@oracle.com
Cc: josef@redhat.com
Cc: viro@zeniv.linux.org.uk
Cc: agruen@linbit.com
Cc: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-28 12:02:09 -04:00
Darrick J. Wong 3d08bcc887 mm: Wait for writeback when grabbing pages to begin a write
When grabbing a page for a buffered IO write, the mm should wait for writeback
on the page to complete so that the page does not become writable during the IO
operation.  This change is needed to provide page stability during writes for
all filesystems.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-28 01:03:21 -04:00
Ingo Molnar d6a72fe465 Merge branch 'tip/perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent 2011-05-27 14:28:09 +02:00
Linus Torvalds dc7acbb251 Merge branch 'upstream/tidy-xen-mmu-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen
* 'upstream/tidy-xen-mmu-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
  xen: fix compile without CONFIG_XEN_DEBUG_FS
  Use arbitrary_virt_to_machine() to deal with ioremapped pud updates.
  Use arbitrary_virt_to_machine() to deal with ioremapped pmd updates.
  xen/mmu: remove all ad-hoc stats stuff
  xen: use normal virt_to_machine for ptes
  xen: make a pile of mmu pvop functions static
  vmalloc: remove vmalloc_sync_all() from alloc_vm_area()
  xen: condense everything onto xen_set_pte
  xen: use mmu_update for xen_set_pte_at()
  xen: drop all the special iomap pte paths.
2011-05-26 19:01:15 -07:00
Ying Han 456f998ec8 memcg: add the pagefault count into memcg stats
Two new stats in per-memcg memory.stat which tracks the number of page
faults and number of major page faults.

  "pgfault"
  "pgmajfault"

They are different from "pgpgin"/"pgpgout" stat which count number of
pages charged/discharged to the cgroup and have no meaning of reading/
writing page to disk.

It is valuable to track the two stats for both measuring application's
performance as well as the efficiency of the kernel page reclaim path.
Counting pagefaults per process is useful, but we also need the aggregated
value since processes are monitored and controlled in cgroup basis in
memcg.

Functional test: check the total number of pgfault/pgmajfault of all
memcgs and compare with global vmstat value:

  $ cat /proc/vmstat | grep fault
  pgfault 1070751
  pgmajfault 553

  $ cat /dev/cgroup/memory.stat | grep fault
  pgfault 1071138
  pgmajfault 553
  total_pgfault 1071142
  total_pgmajfault 553

  $ cat /dev/cgroup/A/memory.stat | grep fault
  pgfault 199
  pgmajfault 0
  total_pgfault 199
  total_pgmajfault 0

Performance test: run page fault test(pft) wit 16 thread on faulting in
15G anon pages in 16G container.  There is no regression noticed on the
"flt/cpu/s"

Sample output from pft:

  TAG pft:anon-sys-default:
    Gb  Thr CLine   User     System     Wall    flt/cpu/s fault/wsec
    15   16   1     0.67s   233.41s    14.76s   16798.546 266356.260

  +-------------------------------------------------------------------------+
      N           Min           Max        Median           Avg        Stddev
  x  10     16682.962     17344.027     16913.524     16928.812      166.5362
  +  10     16695.568     16923.896     16820.604     16824.652     84.816568
  No difference proven at 95.0% confidence

[akpm@linux-foundation.org: fix build]
[hughd@google.com: shmem fix]
Signed-off-by: Ying Han <yinghan@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26 17:12:36 -07:00
Ying Han 406eb0c9ba memcg: add memory.numastat api for numa statistics
The new API exports numa_maps per-memcg basis.  This is a piece of useful
information where it exports per-memcg page distribution across real numa
nodes.

One of the usecases is evaluating application performance by combining
this information w/ the cpu allocation to the application.

The output of the memory.numastat tries to follow w/ simiar format of
numa_maps like:

  total=<total pages> N0=<node 0 pages> N1=<node 1 pages> ...
  file=<total file pages> N0=<node 0 pages> N1=<node 1 pages> ...
  anon=<total anon pages> N0=<node 0 pages> N1=<node 1 pages> ...
  unevictable=<total anon pages> N0=<node 0 pages> N1=<node 1 pages> ...

And we have per-node:

  total = file + anon + unevictable

  $ cat /dev/cgroup/memory/memory.numa_stat
  total=250020 N0=87620 N1=52367 N2=45298 N3=64735
  file=225232 N0=83402 N1=46160 N2=40522 N3=55148
  anon=21053 N0=3424 N1=6207 N2=4776 N3=6646
  unevictable=3735 N0=794 N1=0 N2=0 N3=2941

Signed-off-by: Ying Han <yinghan@google.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26 17:12:36 -07:00
Ying Han 1bac180bd2 memcg: rename mem_cgroup_zone_nr_pages() to mem_cgroup_zone_nr_lru_pages()
The caller of the function has been renamed to zone_nr_lru_pages(), and
this is just fixing up in the memcg code.  The current name is easily to
be mis-read as zone's total number of pages.

Signed-off-by: Ying Han <yinghan@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Cc: Balbir Singh <balbir@in.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>
2011-05-26 17:12:35 -07:00
Johannes Weiner 4fd14ebf6e memcg: remove unused retry signal from reclaim
If the memcg reclaim code detects the target memcg below its limit it
exits and returns a guaranteed non-zero value so that the charge is
retried.

Nowadays, the charge side checks the memcg limit itself and does not rely
on this non-zero return value trick.

This patch removes it.  The reclaim code will now always return the true
number of pages it reclaimed on its own.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Rik van Riel<riel@redhat.com>
Acked-by: Ying Han<yinghan@google.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
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>
2011-05-26 17:12:35 -07:00
KAMEZAWA Hiroyuki 246e87a939 memcg: fix get_scan_count() for small targets
During memory reclaim we determine the number of pages to be scanned per
zone as

	(anon + file) >> priority.
Assume
	scan = (anon + file) >> priority.

If scan < SWAP_CLUSTER_MAX, the scan will be skipped for this time and
priority gets higher.  This has some problems.

  1. This increases priority as 1 without any scan.
     To do scan in this priority, amount of pages should be larger than 512M.
     If pages>>priority < SWAP_CLUSTER_MAX, it's recorded and scan will be
     batched, later. (But we lose 1 priority.)
     If memory size is below 16M, pages >> priority is 0 and no scan in
     DEF_PRIORITY forever.

  2. If zone->all_unreclaimabe==true, it's scanned only when priority==0.
     So, x86's ZONE_DMA will never be recoverred until the user of pages
     frees memory by itself.

  3. With memcg, the limit of memory can be small. When using small memcg,
     it gets priority < DEF_PRIORITY-2 very easily and need to call
     wait_iff_congested().
     For doing scan before priorty=9, 64MB of memory should be used.

Then, this patch tries to scan SWAP_CLUSTER_MAX of pages in force...when

  1. the target is enough small.
  2. it's kswapd or memcg reclaim.

Then we can avoid rapid priority drop and may be able to recover
all_unreclaimable in a small zones.  And this patch removes nr_saved_scan.
 This will allow scanning in this priority even when pages >> priority is
very small.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Ying Han <yinghan@google.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
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>
2011-05-26 17:12:35 -07:00
Ying Han 889976dbcb memcg: reclaim memory from nodes in round-robin order
Presently, memory cgroup's direct reclaim frees memory from the current
node.  But this has some troubles.  Usually when a set of threads works in
a cooperative way, they tend to operate on the same node.  So if they hit
limits under memcg they will reclaim memory from themselves, damaging the
active working set.

For example, assume 2 node system which has Node 0 and Node 1 and a memcg
which has 1G limit.  After some work, file cache remains and the usages
are

   Node 0:  1M
   Node 1:  998M.

and run an application on Node 0, it will eat its foot before freeing
unnecessary file caches.

This patch adds round-robin for NUMA and adds equal pressure to each node.
When using cpuset's spread memory feature, this will work very well.

But yes, a better algorithm is needed.

[akpm@linux-foundation.org: comment editing]
[kamezawa.hiroyu@jp.fujitsu.com: fix time comparisons]
Signed-off-by: Ying Han <yinghan@google.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
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>
2011-05-26 17:12:35 -07:00
Namhyung Kim 6a5b18d2bd memcg: move page-freeing code out of lock
Move page-freeing code out of swap_cgroup_mutex in the hope that it could
reduce few of theoretical contentions between swapons and/or swapoffs.

This is just a cleanup, no functional changes.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26 17:12:35 -07:00
Namhyung Kim 33278f7f0a memcg: fix off-by-one when calculating swap cgroup map length
It allocated one more page than necessary if @max_pages was a multiple of
SC_PER_PAGE.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26 17:12:35 -07:00
Namhyung Kim 268433b8e5 memcg: mark init_section_page_cgroup() properly
Commit ca371c0d7e ("memcg: fix page_cgroup fatal error in FLATMEM")
removes call to alloc_bootmem() in the function so that it can be marked
as __meminit to reduce memory usage when MEMORY_HOTPLUG=n.

Also as the new helper function alloc_page_cgroup() is called only in the
function, it should be marked too.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Michal Hocko <mhocko@suse.cz>
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>
2011-05-26 17:12:35 -07:00
Michal Hocko 39cc98f1f8 memcg: remove pointless next_mz nullification in mem_cgroup_soft_limit_reclaim()
next_mz is assigned to NULL if __mem_cgroup_largest_soft_limit_node
selects the same mz.  This doesn't make much sense as we assign to the
variable right in the next loop.

Compiler will probably optimize this out but it is little bit confusing
for the code reading.

Signed-off-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
2011-05-26 17:12:35 -07:00
Ying Han d149e3b25d memcg: add the soft_limit reclaim in global direct reclaim.
We recently added the change in global background reclaim which counts the
return value of soft_limit reclaim.  Now this patch adds the similar logic
on global direct reclaim.

We should skip scanning global LRU on shrink_zone if soft_limit reclaim
does enough work.  This is the first step where we start with counting the
nr_scanned and nr_reclaimed from soft_limit reclaim into global
scan_control.

Signed-off-by: Ying Han <yinghan@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26 17:12:35 -07:00
Ying Han 0ae5e89c60 memcg: count the soft_limit reclaim in global background reclaim
The global kswapd scans per-zone LRU and reclaims pages regardless of the
cgroup. It breaks memory isolation since one cgroup can end up reclaiming
pages from another cgroup. Instead we should rely on memcg-aware target
reclaim including per-memcg kswapd and soft_limit hierarchical reclaim under
memory pressure.

In the global background reclaim, we do soft reclaim before scanning the
per-zone LRU. However, the return value is ignored. This patch is the first
step to skip shrink_zone() if soft_limit reclaim does enough work.

This is part of the effort which tries to reduce reclaiming pages in global
LRU in memcg. The per-memcg background reclaim patchset further enhances the
per-cgroup targetting reclaim, which I should have V4 posted shortly.

Try running multiple memory intensive workloads within seperate memcgs. Watch
the counters of soft_steal in memory.stat.

  $ cat /dev/cgroup/A/memory.stat | grep 'soft'
  soft_steal 240000
  soft_scan 240000
  total_soft_steal 240000
  total_soft_scan 240000

This patch:

In the global background reclaim, we do soft reclaim before scanning the
per-zone LRU.  However, the return value is ignored.

We would like to skip shrink_zone() if soft_limit reclaim does enough
work.  Also, we need to make the memory pressure balanced across per-memcg
zones, like the logic vm-core.  This patch is the first step where we
start with counting the nr_scanned and nr_reclaimed from soft_limit
reclaim into the global scan_control.

Signed-off-by: Ying Han <yinghan@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Acked-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>
2011-05-26 17:12:35 -07:00
Ben Blum f780bdb7c1 cgroups: add per-thread subsystem callbacks
Add cgroup subsystem callbacks for per-thread attachment in atomic contexts

Add can_attach_task(), pre_attach(), and attach_task() as new callbacks
for cgroups's subsystem interface.  Unlike can_attach and attach, these
are for per-thread operations, to be called potentially many times when
attaching an entire threadgroup.

Also, the old "bool threadgroup" interface is removed, as replaced by
this.  All subsystems are modified for the new interface - of note is
cpuset, which requires from/to nodemasks for attach to be globally scoped
(though per-cpuset would work too) to persist from its pre_attach to
attach_task and attach.

This is a pre-patch for cgroup-procs-writable.patch.

Signed-off-by: Ben Blum <bblum@andrew.cmu.edu>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26 17:12:34 -07:00
Linus Torvalds f8d613e2a6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/djm/tmem
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/djm/tmem:
  xen: cleancache shim to Xen Transcendent Memory
  ocfs2: add cleancache support
  ext4: add cleancache support
  btrfs: add cleancache support
  ext3: add cleancache support
  mm/fs: add hooks to support cleancache
  mm: cleancache core ops functions and config
  fs: add field to superblock to support cleancache
  mm/fs: cleancache documentation

Fix up trivial conflict in fs/btrfs/extent_io.c due to includes
2011-05-26 10:50:56 -07:00
KOSAKI Motohiro ca16d140af mm: don't access vm_flags as 'int'
The type of vma->vm_flags is 'unsigned long'. Neither 'int' nor
'unsigned int'. This patch fixes such misuse.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
[ Changed to use a typedef - we'll extend it to cover more cases
  later, since there has been discussion about making it a 64-bit
  type..                      - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26 09:20:31 -07:00
Dan Magenheimer c515e1fd36 mm/fs: add hooks to support cleancache
This fourth patch of eight in this cleancache series provides the
core hooks in VFS for: initializing cleancache per filesystem;
capturing clean pages reclaimed by page cache; attempting to get
pages from cleancache before filesystem read; and ensuring coherency
between pagecache, disk, and cleancache.  Note that the placement
of these hooks was stable from 2.6.18 to 2.6.38; a minor semantic
change was required due to a patchset in 2.6.39.

All hooks become no-ops if CONFIG_CLEANCACHE is unset, or become
a check of a boolean global if CONFIG_CLEANCACHE is set but no
cleancache "backend" has claimed cleancache_ops.

Details and a FAQ can be found in Documentation/vm/cleancache.txt

[v8: minchan.kim@gmail.com: adapt to new remove_from_page_cache function]
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Reviewed-by: Jeremy Fitzhardinge <jeremy@goop.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik Van Riel <riel@redhat.com>
Cc: Jan Beulich <JBeulich@novell.com>
Cc: Andreas Dilger <adilger@sun.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Nitin Gupta <ngupta@vflare.org>
2011-05-26 10:01:43 -06:00
Dan Magenheimer 077b1f83a6 mm: cleancache core ops functions and config
This third patch of eight in this cleancache series provides
the core code for cleancache that interfaces between the hooks in
VFS and individual filesystems and a cleancache backend.  It also
includes build and config patches.

Two new files are added: mm/cleancache.c and include/linux/cleancache.h.

Note that CONFIG_CLEANCACHE can default to on; in systems that do
not provide a cleancache backend, all hooks devolve to a simple
check of a global enable flag, so performance impact should
be negligible but can be reduced to zero impact if config'ed off.
However for this first commit, it defaults to off.

Details and a FAQ can be found in Documentation/vm/cleancache.txt

Credits: Cleancache_ops design derived from Jeremy Fitzhardinge
design for tmem

[v8: dan.magenheimer@oracle.com: fix exportfs call affecting btrfs]
[v8: akpm@linux-foundation.org: use static inline function, not macro]
[v7: dan.magenheimer@oracle.com: cleanup sysfs and remove cleancache prefix]
[v6: JBeulich@novell.com: robustly handle buggy fs encode_fh actor definition]
[v5: jeremy@goop.org: clean up global usage and static var names]
[v5: jeremy@goop.org: simplify init hook and any future fs init changes]
[v5: hch@infradead.org: cleaner non-global interface for ops registration]
[v4: adilger@sun.com: interface must support exportfs FS's]
[v4: hch@infradead.org: interface must support 64-bit FS on 32-bit kernel]
[v3: akpm@linux-foundation.org: use one ops struct to avoid pointer hops]
[v3: akpm@linux-foundation.org: document and ensure PageLocked reqts are met]
[v3: ngupta@vflare.org: fix success/fail codes, change funcs to void]
[v2: viro@ZenIV.linux.org.uk: use sane types]
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Reviewed-by: Jeremy Fitzhardinge <jeremy@goop.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Nitin Gupta <ngupta@vflare.org>
Acked-by: Minchan Kim <minchan.kim@gmail.com>
Acked-by: Andreas Dilger <adilger@sun.com>
Acked-by: Jan Beulich <JBeulich@novell.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Rik Van Riel <riel@redhat.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
2011-05-26 10:01:36 -06:00
Linus Torvalds 49a78d085f slub: remove no-longer used 'unlock_out' label
Commit a71ae47a2c ("slub: Fix double bit unlock in debug mode")
removed the only goto to this label, resulting in

  mm/slub.c: In function '__slab_alloc':
  mm/slub.c:1834: warning: label 'unlock_out' defined but not used

fixed trivially by the removal of the label itself too.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Christoph Lameter <cl@linux.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 18:06:54 -07:00