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

Nikanth Karthikesan
2009-01-27T11:11:11Z

On Tuesday 27 January 2009 16:23:00 David Rientjes wrote:
> On Tue, 27 Jan 2009, Nikanth Karthikesan wrote:
> > > As previously stated, I think the heuristic to penalize tasks for not
> > > having an intersection with the set of allowable nodes of the oom
> > > triggering task could be made slightly more severe. That's irrelevant
> > > to your patch, though.
> >
> > But the heuristic makes it non-deterministic, unlike memcg case. And this
> > mandates special handling for cpuset constrained OOM conditions in this
> > patch.
>
> Dividing a badness score by 8 if a task's set of allowable nodes do not
> insect with the oom triggering task's set does not make an otherwise
> deterministic algorithm non-deterministic.
>
> I don't understand what you're arguing for here. Are you suggesting that
> we should not prefer tasks that intersect the set of allowable nodes?
> That makes no sense if the goal is to allow for future memory freeing.
>

No. Actually I am just wondering, will it be possible to check whether a
particular task has memory allocated or mmaped from this node to avoid killing
an innocent task. I compared with memcg, to say that memcg never kills a task
not related to the memcg constrained oom. Sorry if I was unclear, earlier. If
we do this, oom-controller will not require special handling for cpuset
constrained ooms.

Thanks
Nikanth