Re: [v8 0/4] cgroup-aware OOM killer

Michal Hocko
2017-09-13T12:29:14Z

On Mon 11-09-17 13:44:39, David Rientjes wrote:
> On Mon, 11 Sep 2017, Roman Gushchin wrote:
>
> > This patchset makes the OOM killer cgroup-aware.
> >
> > v8:
> > - Do not kill tasks with OOM_SCORE_ADJ -1000
> > - Make the whole thing opt-in with cgroup mount option control
> > - Drop oom_priority for further discussions
>
> Nack, we specifically require oom_priority for this to function correctly,
> otherwise we cannot prefer to kill from low priority leaf memcgs as
> required.

While I understand that your usecase might require priorities I do not
think this part missing is a reason to nack the cgroup based selection
and kill-all parts. This can be done on top. The only important part
right now is the current selection semantic - only leaf memcgs vs. size
of the hierarchy). I strongly believe that comparing only leaf memcgs
is more straightforward and it doesn't lead to unexpected results as
mentioned before (kill a small memcg which is a part of the larger
sub-hierarchy).

I didn't get to read the new version of this series yet and hope to get
to it soon.
--
Michal Hocko
SUSE Labs