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
