On Wed 13-09-17 14:56:07, Roman Gushchin wrote: > On Wed, Sep 13, 2017 at 02:29:14PM +0200, Michal Hocko wrote: [...] > > 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). > > One of two main goals of this patchset is to introduce cgroup-level > fairness: bigger cgroups should be affected more than smaller, > despite the size of tasks inside. I believe the same principle > should be used for cgroups. Yes bigger cgroups should be preferred but I fail to see why bigger hierarchies should be considered as well if they are not kill-all. And whether non-leaf memcgs should allow kill-all is not entirely clear to me. What would be the usecase? Consider that it might be not your choice (as a user) how deep is your leaf memcg. I can already see how people complain that their memcg has been killed just because it was one level deeper in the hierarchy... I would really start simple and only allow kill-all on leaf memcgs and only compare leaf memcgs & root. If we ever need to kill whole hierarchies then allow kill-all on intermediate memcgs as well and then consider cumulative consumptions only on those that have kill-all enabled. Or do I miss any reasonable usecase that would suffer from such a semantic? -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
