Commit 591edfb1 authored by Roman Gushchin's avatar Roman Gushchin Committed by Linus Torvalds

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@fb.comSigned-off-by: default avatarRoman Gushchin <guro@fb.com>
Reviewed-by: default avatarShakeel Butt <shakeelb@google.com>
Acked-by: default avatarMichal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9b6f7e16
...@@ -4573,6 +4573,8 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css) ...@@ -4573,6 +4573,8 @@ static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
memcg_offline_kmem(memcg); memcg_offline_kmem(memcg);
wb_memcg_offline(memcg); wb_memcg_offline(memcg);
drain_all_stock(memcg);
mem_cgroup_id_put(memcg); mem_cgroup_id_put(memcg);
} }
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment