Re: [PATCH 1/1] mm, oom_adj: don't loop through tasks in __set_oom_adj when not necessary

Michal Hocko
2020-08-20T11:15:13Z

On Thu 20-08-20 12:32:48, Christian Brauner wrote:
> On Thu, Aug 20, 2020 at 11:09:01AM +0200, Michal Hocko wrote:
> > On Thu 20-08-20 10:46:54, Christian Brauner wrote:
[...]
> > > > which includes processes with multiple threads (sharing mm and signals).
> > > > However for such processes the loop is unnecessary because their signal
> > > > structure is shared as well.
>
> and it seems you want to exclude threads, i.e. only update mm that is
> shared not among threads in the same thread-group.
> But struct signal and struct sighand_struct are different things, i.e.
> they can be shared or not independent of each other. A non-shared
> signal_struct where oom_score_adj{_min} live is only implied by
> !CLONE_THREAD. So shouldn't this be:
>
> if (!(clone_flags & CLONE_THREAD)) rather than CLONE_SIGHAND?

You are right as I have already replied to Oleg.

--
Michal Hocko
SUSE Labs