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| author | David Rientjes <rientjes@google.com> | 2010-10-26 14:21:23 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-10-26 16:52:05 -0700 |
| commit | e18641e19a9204f241f04a5ac700168dcd18de4f (patch) | |
| tree | f1058203588bd31584d217a25fabe4f7085a1f44 /mm | |
| parent | 3d5992d2ac7dc09aed8ab537cba074589f0f0a52 (diff) | |
| download | linux-e18641e19a9204f241f04a5ac700168dcd18de4f.tar.gz linux-e18641e19a9204f241f04a5ac700168dcd18de4f.tar.bz2 linux-e18641e19a9204f241f04a5ac700168dcd18de4f.zip | |
oom: avoid killing a task if a thread sharing its mm cannot be killed
The oom killer's goal is to kill a memory-hogging task so that it may
exit, free its memory, and allow the current context to allocate the
memory that triggered it in the first place. Thus, killing a task is
pointless if other threads sharing its mm cannot be killed because of its
/proc/pid/oom_adj or /proc/pid/oom_score_adj value.
This patch checks whether any other thread sharing p->mm has an
oom_score_adj of OOM_SCORE_ADJ_MIN. If so, the thread cannot be killed
and oom_badness(p) returns 0, meaning it's unkillable.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ying Han <yinghan@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/oom_kill.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 4029583a1024..4395f371bc7c 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -162,10 +162,11 @@ unsigned int oom_badness(struct task_struct *p, struct mem_cgroup *mem, return 0; /* - * Shortcut check for OOM_SCORE_ADJ_MIN so the entire heuristic doesn't - * need to be executed for something that cannot be killed. + * Shortcut check for a thread sharing p->mm that is OOM_SCORE_ADJ_MIN + * so the entire heuristic doesn't need to be executed for something + * that cannot be killed. */ - if (p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) { + if (atomic_read(&p->mm->oom_disable_count)) { task_unlock(p); return 0; } @@ -680,7 +681,7 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, read_lock(&tasklist_lock); if (sysctl_oom_kill_allocating_task && !oom_unkillable_task(current, NULL, nodemask) && - (current->signal->oom_adj != OOM_DISABLE)) { + current->mm && !atomic_read(¤t->mm->oom_disable_count)) { /* * oom_kill_process() needs tasklist_lock held. If it returns * non-zero, current could not be killed so we must fallback to |