On Tue 26-09-17 13:13:00, Roman Gushchin wrote: > On Tue, Sep 26, 2017 at 01:21:34PM +0200, Michal Hocko wrote: > > On Tue 26-09-17 11:59:25, Roman Gushchin wrote: > > > On Mon, Sep 25, 2017 at 10:25:21PM +0200, Michal Hocko wrote: > > > > On Mon 25-09-17 19:15:33, Roman Gushchin wrote: > > > > [...] > > > > > I'm not against this model, as I've said before. It feels logical, > > > > > and will work fine in most cases. > > > > > > > > > > In this case we can drop any mount/boot options, because it preserves > > > > > the existing behavior in the default configuration. A big advantage. > > > > > > > > I am not sure about this. We still need an opt-in, ragardless, because > > > > selecting the largest process from the largest memcg != selecting the > > > > largest task (just consider memcgs with many processes example). > > > > > > As I understand Johannes, he suggested to compare individual processes with > > > group_oom mem cgroups. In other words, always select a killable entity with > > > the biggest memory footprint. > > > > > > This is slightly different from my v8 approach, where I treat leaf memcgs > > > as indivisible memory consumers independent on group_oom setting, so > > > by default I'm selecting the biggest task in the biggest memcg. > > > > My reading is that he is actually proposing the same thing I've been > > mentioning. Simply select the biggest killable entity (leaf memcg or > > group_oom hierarchy) and either kill the largest task in that entity > > (for !group_oom) or the whole memcg/hierarchy otherwise. > > He wrote the following: > "So I'm leaning toward the second model: compare all oomgroups and > standalone tasks in the system with each other, independent of the > failed hierarchical control structure. Then kill the biggest of them." I will let Johannes to comment but I believe this is just a misunderstanding. If we compared only the biggest task from each memcg then we are basically losing our fairness objective, aren't we? -- 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
