On Thu 26-01-17 17:18:58, Trevor Cordes wrote:
> On 2017-01-24 Michal Hocko wrote:
> > On Sun 22-01-17 18:45:59, Trevor Cordes wrote:
> > [...]
> > > Also, completely separate from your patch I ran mhocko's 4.9 tree
> > > with mem=2G to see if lower ram amount would help, but it didn't.
> > > Even with 2G the system oom and hung same as usual. So far the
> > > only thing that helps at all was the cgroup_disable=memory option,
> > > which makes the problem disappear completely for me.
> >
> > OK, can we reduce the problem space slightly more and could you boot
> > with kmem accounting enabled? cgroup.memory=nokmem,nosocket
>
> I ran for 30 hours with cgroup.memory=nokmem,nosocket using vanilla
> 4.9.0+ and it oom'd during a big rdiff-backup at 9am. My script was
> able to reboot it before it hung. Only one oom occurred before the
> reboot, which is a bit odd, usually there is 5-50. See attached
> messages log (oom6).
>
> So, still, only cgroup_disable=memory mitigates this bug (so far). If
> you need me to test cgroup.memory=nokmem,nosocket with your since-4.9
> branch specifically, let me know and I'll add it to the to-test list.
OK, that matches the theory that these OOMs are caused by the incorrect
active list aging fixed by b4536f0c829c ("mm, memcg: fix the active list
aging for lowmem requests when memcg is enabled")
--
Michal Hocko
SUSE Labs
