Re: [RFC] [PATCH] Cgroup based OOM killer controller

KOSAKI Motohiro
2009-01-27T07:02:47Z

Hi

> > > As Alan Cox suggested/wondered in this thread,
> > > http://lkml.org/lkml/2009/1/12/235 , this is a container group based approach
> > > to override the oom killer selection without losing all the benefits of the
> > > current oom killer heuristics and oom_adj interface.
> > >
> > > It adds a tunable oom.victim to the oom cgroup. The oom killer will kill the
> > > process using the usual badness value but only within the cgroup with the
> > > maximum value for oom.victim before killing any process from a cgroup with a
> > > lesser oom.victim number. Oom killing could be disabled by setting
> > > oom.victim=0.
> >
> > Looking at the patch, I wonder if it is time for user space OOM
> > notifications that were discussed during the containers mini-summit.
> > The idea is to inform user space about OOM's and let user space take
> > action, if no action is taken, the default handler kicks in.
>
> The OLPC folks (Marcelo I believe) posted code for this and I believe
> OLPC is using this functionality internally so that under memory pressure
> (before we actually hit OOM) programs can respond by doing stuff like
> evicting caches.

Confused.

As far as I know, people want the method of flexible cache treating.
but oom seems less flexible than userland notification.

Why do you think notification is bad?