On Fri, Dec 03, 2021 at 04:45:54PM -0800, Shakeel Butt wrote: > On Fri, Dec 3, 2021 at 8:24 AM Dan Schatzberg <schatzberg.dan@xxxxxxxxx> wrote: > > > > Our container agent wants to know when a container exits if it was OOM > > killed or not to report to the user. We use memory.oom.group = 1 to > > ensure that OOM kills within the container's cgroup kill > > everything. Existing memory.events are insufficient for knowing if > > this triggered: > > > > 1) Our current approach reads memory.events oom_kill and reports the > > container was killed if the value is non-zero. This is erroneous in > > some cases where containers create their children cgroups with > > memory.oom.group=1 as such OOM kills will get counted against the > > container cgroup's oom_kill counter despite not actually OOM killing > > the entire container. > > > > 2) Reading memory.events.local will fail to identify OOM kills in leaf > > cgroups (that don't set memory.oom.group) within the container cgroup. > > > > This patch adds a new oom_group_kill event when memory.oom.group > > triggers to allow userspace to cleanly identify when an entire cgroup > > is oom killed. > > > > Signed-off-by: Dan Schatzberg <schatzberg.dan@xxxxxxxxx> > > So, with this patch, will you be watching oom_group_kill from > memory.events or memory.events.local file for your use-case? > > Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx> We will watch from memory.events.local. If containers want to construct their own child cgroups and allow for group oom to occur inside, that's fine - a future container exit should not result in us claiming the container was OOM killed. If the container exits and memory.event.local shows oom_group_kill > 0 then we know the container was OOM killed.
