Re: + mm-consider-subtrees-in-memoryevents.patch added to -mm tree

[Johannes Weiner <hannes@cmpxchg.org>]

On Fri, May 17, 2019 at 06:00:11AM -0700, Shakeel Butt wrote:
> On Wed, Feb 13, 2019 at 4:47 AM Michal Hocko <mhocko@kernel.org> wrote:
> > > notifications.
> > >
> > > After this patch, events are propagated up the hierarchy:
> > >
> > >     [root@ktst ~]# cat /sys/fs/cgroup/system.slice/memory.events
> > >     low 0
> > >     high 0
> > >     max 0
> > >     oom 0
> > >     oom_kill 0
> > >     [root@ktst ~]# systemd-run -p MemoryMax=1 true
> > >     Running as unit: run-r251162a189fb4562b9dabfdc9b0422f5.service
> > >     [root@ktst ~]# cat /sys/fs/cgroup/system.slice/memory.events
> > >     low 0
> > >     high 0
> > >     max 7
> > >     oom 1
> > >     oom_kill 1
> > >
> > > As this is a change in behaviour, this can be reverted to the old
> > > behaviour by mounting with the `memory_localevents' flag set.  However, we
> > > use the new behaviour by default as there's a lack of evidence that there
> > > are any current users of memory.events that would find this change
> > > undesirable.
> > >
> > > Link: http://lkml.kernel.org/r/20190208224419.GA24772@chrisdown.name
> > > Signed-off-by: Chris Down <chris@chrisdown.name>
> > > Acked-by: Johannes Weiner <hannes@cmpxchg.org>
> 
> Reviewed-by: Shakeel Butt <shakeelb@google.com>

Thanks, Shakeel.

> However can we please have memory.events.local merged along with this one?

Could I ask you to send a patch for this? It's not really about the
code - that should be trivial. Rather it's about laying out the exact
usecase for that, which is harder for me/Chris/FB since we don't have
one. I imagine simliar arguments could be made for memory.stat.local,
memory.pressure.local etc. since they're also reporting events and
behavior manifesting in different levels of the cgroup subtree?