linux.git/mm/oom_kill.c, branch v2.6.30

oom: fix possible oom_dump_tasks NULL pointer

2009-05-29T15:40:01+00:00

When /proc/sys/vm/oom_dump_tasks is enabled, it is possible to get a NULL
pointer for tasks that have detached mm's since task_lock() is not held
during the tasklist scan.  Add the task_lock().

Acked-by: Nick Piggin 
Acked-by: Mel Gorman 
Cc: Rik van Riel 
Signed-off-by: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

oom: prevent livelock when oom_kill_allocating_task is set

2009-05-06T23:36:09+00:00

When /proc/sys/vm/oom_kill_allocating_task is set for large systems that
want to avoid the lengthy tasklist scan, it's possible to livelock if
current is ineligible for oom kill.  This normally happens when it is set
to OOM_DISABLE, but is also possible if any threads are sharing the same
->mm with a different tgid.

So change __out_of_memory() to fall back to the full task-list scan if it
was unable to kill `current'.

Cc: Nick Piggin 
Signed-off-by: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memcg: show memcg information during OOM

2009-04-03T02:04:55+00:00

Add RSS and swap to OOM output from memcg

Display memcg values like failcnt, usage and limit when an OOM occurs due
to memcg.

Thanks to Johannes Weiner, Li Zefan, David Rientjes, Kamezawa Hiroyuki,
Daisuke Nishimura and KOSAKI Motohiro for review.

Sample output
-------------

Task in /a/x killed as a result of limit of /a
memory: usage 1048576kB, limit 1048576kB, failcnt 4183
memory+swap: usage 1400964kB, limit 9007199254740991kB, failcnt 0

[akpm@linux-foundation.org: compilation fix]
[akpm@linux-foundation.org: fix kerneldoc and whitespace]
[akpm@linux-foundation.org: add printk facility level]
Signed-off-by: Balbir Singh 
Cc: KAMEZAWA Hiroyuki 
Cc: Daisuke Nishimura 
Cc: Li Zefan 
Cc: Paul Menage 
Cc: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

oom_kill: don't call for int_sqrt(0)

2009-04-01T15:59:11+00:00

There is no need to call for int_sqrt if argument is 0.

Signed-off-by: Cyrill Gorcunov 
Cc: Pekka Enberg 
Cc: Christoph Lameter 
Acked-by: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memcg: avoid deadlock caused by race between oom and cpuset_attach

2009-01-08T16:31:09+00:00

mpol_rebind_mm(), which can be called from cpuset_attach(), does
down_write(mm->mmap_sem).  This means down_write(mm->mmap_sem) can be
called under cgroup_mutex.

OTOH, page fault path does down_read(mm->mmap_sem) and calls
mem_cgroup_try_charge_xxx(), which may eventually calls
mem_cgroup_out_of_memory().  And mem_cgroup_out_of_memory() calls
cgroup_lock().  This means cgroup_lock() can be called under
down_read(mm->mmap_sem).

If those two paths race, deadlock can happen.

This patch avoid this deadlock by:
  - remove cgroup_lock() from mem_cgroup_out_of_memory().
  - define new mutex (memcg_tasklist) and serialize mem_cgroup_move_task()
    (->attach handler of memory cgroup) and mem_cgroup_out_of_memory.

Signed-off-by: Daisuke Nishimura 
Reviewed-by: KAMEZAWA Hiroyuki 
Acked-by: Balbir Singh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memcg: avoid unnecessary system-wide-oom-killer

2009-01-08T16:31:06+00:00

Current mmtom has new oom function as pagefault_out_of_memory().  It's
added for select bad process rathar than killing current.

When memcg hit limit and calls OOM at page_fault, this handler called and
system-wide-oom handling happens.  (means kernel panics if panic_on_oom is
true....)

To avoid overkill, check memcg's recent behavior before starting
system-wide-oom.

And this patch also fixes to guarantee "don't accnout against process with
TIF_MEMDIE".  This is necessary for smooth OOM.

[akpm@linux-foundation.org: build fix]
Signed-off-by: KAMEZAWA Hiroyuki 
Cc: Li Zefan 
Cc: Balbir Singh 
Cc: Daisuke Nishimura 
Cc: Badari Pulavarty 
Cc: Jan Blunck 
Cc: Hirokazu Takahashi 
Cc: Nick Piggin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

oom: print triggering task's cpuset and mems allowed

2009-01-06T23:58:59+00:00

When cpusets are enabled, it's necessary to print the triggering task's
set of allowable nodes so the subsequently printed meminfo can be
interpreted correctly.

We also print the task's cpuset name for informational purposes.

[rientjes@google.com: task lock current before dereferencing cpuset]
Cc: Paul Menage 
Cc: Li Zefan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

oom: fix zone_scan_mutex name

2009-01-06T23:58:58+00:00

zone_scan_mutex is actually a spinlock, so name it appropriately.

Signed-off-by: David Rientjes 
Reviewed-by: KOSAKI Motohiro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: invoke oom-killer from page fault

2009-01-06T23:58:58+00:00

Rather than have the pagefault handler kill a process directly if it gets
a VM_FAULT_OOM, have it call into the OOM killer.

With increasingly sophisticated oom behaviour (cpusets, memory cgroups,
oom killing throttling, oom priority adjustment or selective disabling,
panic on oom, etc), it's silly to unconditionally kill the faulting
process at page fault time.  Create a hook for pagefault oom path to call
into instead.

Only converted x86 and uml so far.

[akpm@linux-foundation.org: make __out_of_memory() static]
[akpm@linux-foundation.org: fix comment]
Signed-off-by: Nick Piggin 
Cc: Jeff Dike 
Acked-by: Ingo Molnar 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'master' into next

2008-11-14T00:29:12+00:00

Conflicts:
	security/keys/internal.h
	security/keys/process_keys.c
	security/keys/request_key.c

Fixed conflicts above by using the non 'tsk' versions.

Signed-off-by: James Morris