On Wed, Oct 04, 2017 at 04:46:36PM +0100, Roman Gushchin wrote: > The cgroup-aware OOM killer treats leaf memory cgroups as memory > consumption entities and performs the victim selection by comparing > them based on their memory footprint. Then it kills the biggest task > inside the selected memory cgroup. > > But there are workloads, which are not tolerant to a such behavior. > Killing a random task may leave the workload in a broken state. > > To solve this problem, memory.oom_group knob is introduced. > It will define, whether a memory group should be treated as an > indivisible memory consumer, compared by total memory consumption > with other memory consumers (leaf memory cgroups and other memory > cgroups with memory.oom_group set), and whether all belonging tasks > should be killed if the cgroup is selected. > > If set on memcg A, it means that in case of system-wide OOM or > memcg-wide OOM scoped to A or any ancestor cgroup, all tasks, > belonging to the sub-tree of A will be killed. If OOM event is > scoped to a descendant cgroup (A/B, for example), only tasks in > that cgroup can be affected. OOM killer will never touch any tasks > outside of the scope of the OOM event. > > Also, tasks with oom_score_adj set to -1000 will not be killed. > > The default value is 0. > > 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 Those semantics make sense to me and the code looks good. Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> -- 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>
