Messages in this thread | | | Date | Thu, 16 Oct 2014 23:02:21 -0400 | From | Johannes Weiner <> | Subject | Re: [patch 4/5] mm: memcontrol: continue cache reclaim from offlined groups |
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On Wed, Oct 15, 2014 at 05:25:55PM +0200, Michal Hocko wrote: > On Tue 14-10-14 12:20:36, Johannes Weiner wrote: > > On cgroup deletion, outstanding page cache charges are moved to the > > parent group so that they're not lost and can be reclaimed during > > pressure on/inside said parent. But this reparenting is fairly tricky > > and its synchroneous nature has led to several lock-ups in the past. > > > > Since css iterators now also include offlined css, memcg iterators can > > be changed to include offlined children during reclaim of a group, and > > leftover cache can just stay put. > > I think it would be nice to mention c2931b70a32c (cgroup: iterate > cgroup_subsys_states directly) here to have a full context about the > tryget vs tryget_online.
Yes, that commit is probably the most direct dependency.
Andrew, could you update the changelog in place to have that paragraph read
Since c2931b70a32c ("cgroup: iterate cgroup_subsys_states directly") css iterators now also include offlined css, so memcg iterators can be changed to include offlined children during reclaim of a group, and leftover cache can just stay put.
please? Thanks!
> > There is a slight change of behavior in that charges of deleted groups > > no longer show up as local charges in the parent. But they are still > > included in the parent's hierarchical statistics. > > Thank you for pulling drain_stock cleanup out. This made the patch so > much easier to review. > > > Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> > > Acked-by: Michal Hocko <mhocko@suse.cz>
Thanks you!
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