Re: Possible race condition in oom-killer

From: Michal Hocko
Date: Tue Aug 01 2017 - 10:47:57 EST


On Tue 01-08-17 23:16:13, Tetsuo Handa wrote:
> Michal Hocko wrote:
> > Once we merge [1] then the oom victim wouldn't
> > need to get TIF_MEMDIE to access memory reserves.
> >
> > [1] http://lkml.kernel.org/r/20170727090357.3205-2-mhocko@xxxxxxxxxx
>
> False. We are not setting oom_mm to all thread groups (!CLONE_THREAD) sharing
> that mm (CLONE_VM). Thus, one thread from each thread group sharing that mm
> will have to call out_of_memory() in order to set oom_mm, and they will find
> task_will_free_mem() returning false due to MMF_OOM_SKIP already set, and
> after all goes to next OOM victim selection.

Once the patch is merged we can mark_oom_victim all of them as well.
--
Michal Hocko
SUSE Labs