Re: [patch 03/12] mm: oom_kill: switch test-and-clear of known TIF_MEMDIE to clear

Michal Hocko
2015-03-26T11:57:43Z

On Wed 25-03-15 02:17:07, Johannes Weiner wrote:
> exit_oom_victim() already knows that TIF_MEMDIE is set, and nobody
> else can clear it concurrently. Use clear_thread_flag() directly.

Yeah. This is a left over from the review process. I originally did
unmarking unconditionally but Tejun suggested calling test_thread_flag
before calling here. So the test_and_clear is safe here.

> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>

Acked-by: Michal Hocko <mhocko@suse.cz>

> ---
> mm/oom_kill.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
> index b2f081fe4b1a..4b9547be9170 100644
> --- a/mm/oom_kill.c
> +++ b/mm/oom_kill.c
> @@ -435,8 +435,7 @@ void mark_oom_victim(struct task_struct *tsk)
> */
> void exit_oom_victim(void)
> {
> - if (!test_and_clear_thread_flag(TIF_MEMDIE))
> - return;
> + clear_thread_flag(TIF_MEMDIE);
>
> down_read(&oom_sem);
> /*
> --
> 2.3.3
>

--
Michal Hocko
SUSE Labs