diff options
| author | David Rientjes <rientjes@google.com> | 2011-10-31 17:07:15 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-10-31 17:30:45 -0700 |
| commit | c9f01245b6a7d77d17deaa71af10f6aca14fa24e (patch) | |
| tree | 13ffde591a5bcefba39cb6393f09b27f1ebc1a30 /fs/exec.c | |
| parent | 7b0d44fa49b1dcfdcf4897f12ddd12ddeab1a9d7 (diff) | |
oom: remove oom_disable_count
This removes mm->oom_disable_count entirely since it's unnecessary and
currently buggy. The counter was intended to be per-process but it's
currently decremented in the exit path for each thread that exits, causing
it to underflow.
The count was originally intended to prevent oom killing threads that
share memory with threads that cannot be killed since it doesn't lead to
future memory freeing. The counter could be fixed to represent all
threads sharing the same mm, but it's better to remove the count since:
- it is possible that the OOM_DISABLE thread sharing memory with the
victim is waiting on that thread to exit and will actually cause
future memory freeing, and
- there is no guarantee that a thread is disabled from oom killing just
because another thread sharing its mm is oom disabled.
Signed-off-by: David Rientjes <rientjes@google.com>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Ying Han <yinghan@google.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>
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/fs/exec.c b/fs/exec.c index 25dcbe5fc35..36254645b7c 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -841,10 +841,6 @@ static int exec_mmap(struct mm_struct *mm) tsk->mm = mm; tsk->active_mm = mm; activate_mm(active_mm, mm); - if (old_mm && tsk->signal->oom_score_adj == OOM_SCORE_ADJ_MIN) { - atomic_dec(&old_mm->oom_disable_count); - atomic_inc(&tsk->mm->oom_disable_count); - } task_unlock(tsk); arch_pick_mmap_layout(mm); if (old_mm) { |