On Wed 04-10-17 16:46:35, Roman Gushchin wrote: > Traditionally, the OOM killer is operating on a process level. > Under oom conditions, it finds a process with the highest oom score > and kills it. > > This behavior doesn't suit well the system with many running > containers: > > 1) There is no fairness between containers. A small container with > few large processes will be chosen over a large one with huge > number of small processes. > > 2) Containers often do not expect that some random process inside > will be killed. In many cases much safer behavior is to kill > all tasks in the container. Traditionally, this was implemented > in userspace, but doing it in the kernel has some advantages, > especially in a case of a system-wide OOM. > > To address these issues, the cgroup-aware OOM killer is introduced. > > Under OOM conditions, it looks for the biggest leaf memory cgroup > and kills the biggest task belonging to it. The following patches > will extend this functionality to consider non-leaf memory cgroups > as well, and also provide an ability to kill all tasks belonging > to the victim cgroup. > > The root cgroup is treated as a leaf memory cgroup, so it's score > is compared with leaf memory cgroups. > Due to memcg statistics implementation a special algorithm > is used for estimating it's oom_score: we define it as maximum > oom_score of the belonging tasks. Thanks for separating the group_oom part. This is getting in the mergeable state. I will ack it once the suggested fixes are folded in. There is some clean up potential on top (I find the oc->chosen_memcg quite ugly and will post a patch on top of yours) but that can be done later. > Signed-off-by: Roman Gushchin <guro@xxxxxx> > Cc: Michal Hocko <mhocko@xxxxxxxxxx> > Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> > Cc: Johannes Weiner <hannes@xxxxxxxxxxx> > Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> > Cc: David Rientjes <rientjes@xxxxxxxxxx> > Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> > Cc: Tejun Heo <tj@xxxxxxxxxx> > Cc: kernel-team@xxxxxx > Cc: cgroups@xxxxxxxxxxxxxxx > Cc: linux-doc@xxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx > Cc: linux-mm@xxxxxxxxx -- Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
