Re: [PATCH 0/3] introduce memory.oom.group

[Michal Hocko <mhocko@kernel.org>]

On Tue 07-08-18 15:34:58, David Rientjes wrote:
> On Mon, 6 Aug 2018, Roman Gushchin wrote:
> 
> > > In a cgroup-aware oom killer world, yes, we need the ability to specify 
> > > that the usage of the entire subtree should be compared as a single 
> > > entity with other cgroups.  That is necessary for user subtrees but may 
> > > not be necessary for top-level cgroups depending on how you structure your 
> > > unified cgroup hierarchy.  So it needs to be configurable, as you suggest, 
> > > and you are correct it can be different than oom.group.
> > > 
> > > That's not the only thing we need though, as I'm sure you were expecting 
> > > me to say :)
> > > 
> > > We need the ability to preserve existing behavior, i.e. process based and 
> > > not cgroup aware, for subtrees so that our users who have clear 
> > > expectations and tune their oom_score_adj accordingly based on how the oom 
> > > killer has always chosen processes for oom kill do not suddenly regress.
> > 
> > Isn't the combination of oom.group=0 and oom.evaluate_together=1 describing
> > this case? This basically means that if memcg is selected as target,
> > the process inside will be selected using traditional per-process approach.
> > 
> 
> No, that would overload the policy and mechanism.  We want the ability to 
> consider user-controlled subtrees as a single entity for comparison with 
> other user subtrees to select which subtree to target.  This does not 
> imply that users want their entire subtree oom killed.

Yeah, that's why oom.group == 0, no?

Anyway, can we separate this discussion from the current series please?
We are getting more and more tangent.

Or do you still see the current state to be not mergeable?
-- 
Michal Hocko
SUSE Labs