On Tue 10-10-17 14:13:00, David Rientjes wrote: [...] > For these reasons: unfair comparison of root mem cgroup usage to bias > against that mem cgroup from oom kill in system oom conditions, the > ability of users to completely evade the oom killer by attaching all > processes to child cgroups either purposefully or unpurposefully, and the > inability of userspace to effectively control oom victim selection: > > Nacked-by: David Rientjes <rientjes@xxxxxxxxxx> I consider this NACK rather dubious. Evading the heuristic as you describe requires root privileges in default configuration because normal users are not allowed to create subtrees. If you really want to delegate subtree to an untrusted entity then you do not have to opt-in for this oom strategy. We can work on an additional means which would allow to cover those as well (e.g. priority based one which is requested for other usecases). A similar argument applies to the root memcg evaluation. While the proposed behavior is not optimal it would work for general usecase described here where the root memcg doesn't really run any large number of tasks. If somebody who explicitly opts-in for the new strategy and it doesn't work well for that usecase we can enhance the behavior. That alone is not a reason to nack the whole thing. I find it really disturbing that you keep nacking this approach just because it doesn't suite your specific usecase while it doesn't break it. Moreover it has been stated several times already that future improvements are possible and cover what you have described already. -- 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
