The patch titled
Subject: mm: drain memcg stocks on css offlining
has been added to the -mm tree. Its filename is
mm-drain-memcg-stocks-on-css-offlining.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-drain-memcg-stocks-on-css-offlining.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-drain-memcg-stocks-on-css-offlining.patch
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------------------------------------------------------
From: Roman Gushchin <guro@xxxxxx>
Subject: mm: drain memcg stocks on css offlining
Memcg charge is batched using per-cpu stocks, so an offline memcg can be
pinned by a cached charge up to a moment, when a process belonging to some
other cgroup will charge some memory on the same cpu. In other words,
cached charges can prevent a memory cgroup from being reclaimed for some
time, without any clear need.
Let's optimize it by explicit draining of all stocks on css offlining. As
draining is performed asynchronously, and is skipped if any parallel
draining is happening, it's cheap.
Link: http://lkml.kernel.org/r/20180827162621.30187-2-guro@xxxxxx
Signed-off-by: Roman Gushchin <guro@xxxxxx>
Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Konstantin Khlebnikov <koct9i@xxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 2 ++
1 file changed, 2 insertions(+)
--- a/mm/memcontrol.c~mm-drain-memcg-stocks-on-css-offlining
+++ a/mm/memcontrol.c
@@ -4573,6 +4573,8 @@ static void mem_cgroup_css_offline(struc
memcg_offline_kmem(memcg);
wb_memcg_offline(memcg);
+ drain_all_stock(memcg);
+
mem_cgroup_id_put(memcg);
}
_
Patches currently in -mm which might be from guro@xxxxxx are
mm-rework-memcg-kernel-stack-accounting.patch
mm-drain-memcg-stocks-on-css-offlining.patch
mm-dont-miss-the-last-page-because-of-round-off-error.patch
