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| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2016-06-24 23:48:38 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-06-25 02:23:52 +0200 |
| commit | 9df10fb7b80bc2f540956ba01b5e7ee1012001a5 (patch) | |
| tree | a64cab11f81e017ca0b27d785e6922d008231403 /mm | |
| parent | mm,oom_reaper: don't call mmput_async() without atomic_inc_not_zero() (diff) | |
| download | linux-9df10fb7b80bc2f540956ba01b5e7ee1012001a5.tar.xz linux-9df10fb7b80bc2f540956ba01b5e7ee1012001a5.zip | |
oom_reaper: avoid pointless atomic_inc_not_zero usage.
Since commit 36324a990cf5 ("oom: clear TIF_MEMDIE after oom_reaper
managed to unmap the address space") changed to use find_lock_task_mm()
for finding a mm_struct to reap, it is guaranteed that mm->mm_users > 0
because find_lock_task_mm() returns a task_struct with ->mm != NULL.
Therefore, we can safely use atomic_inc().
Link: http://lkml.kernel.org/r/1465024759-8074-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
| -rw-r--r-- | mm/oom_kill.c | 8 |
1 files changed, 1 insertions, 7 deletions
diff --git a/mm/oom_kill.c b/mm/oom_kill.c index be67df3b6569..ddf74487f848 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -474,14 +474,8 @@ static bool __oom_reap_task(struct task_struct *tsk) p = find_lock_task_mm(tsk); if (!p) goto unlock_oom; - mm = p->mm; - if (!atomic_inc_not_zero(&mm->mm_users)) { - task_unlock(p); - mm = NULL; - goto unlock_oom; - } - + atomic_inc(&mm->mm_users); task_unlock(p); if (!down_read_trylock(&mm->mmap_sem)) { |