Re: mm, oom_reaper: How to handle race with oom_killer_disable() ?

[Michal Hocko]

On Wed 22-06-16 00:32:29, Tetsuo Handa wrote:
> Michal Hocko wrote:
[...]
> > Hmm, what about the following instead. It is rather a workaround than a
> > full flaged fix but it seems much more easier and shouldn't introduce
> > new issues.
> 
> Yes, I think that will work. But I think below patch (marking signal_struct
> to ignore TIF_MEMDIE instead of clearing TIF_MEMDIE from task_struct) on top of
> current linux.git will implement no-lockup requirement. No race is possible unlike
> "[PATCH 10/10] mm, oom: hide mm which is shared with kthread or global init".

Not really. Because without the exit_oom_victim from oom_reaper you have
no guarantee that the oom_killer_disable will ever return. I have
mentioned that in the changelog. There is simply no guarantee the oom
victim will ever reach exit_mm->exit_oom_victim.
-- 
Michal Hocko
SUSE Labs