From: Shakeel Butt <shakeelb@xxxxxxxxxx>
Subject: mm, memcg: fix mem_cgroup_swapout() for THPs
d6810d730022 ("memcg, THP, swap: make mem_cgroup_swapout() support THP")
changed mem_cgroup_swapout() to support transparent huge page (THP).
However the patch missed one location which should be changed for
correctly handling THPs. The resulting bug will cause the memory cgroups
whose THPs were swapped out to become zombies on deletion.
Link: http://lkml.kernel.org/r/20171128161941.20931-1-shakeelb@xxxxxxxxxx
Fixes: d6810d730022 ("memcg, THP, swap: make mem_cgroup_swapout() support THP")
Signed-off-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Huang Ying <ying.huang@xxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Cc: Greg Thelen <gthelen@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN mm/memcontrol.c~mm-memcg-fix-mem_cgroup_swapout-for-thps mm/memcontrol.c
--- a/mm/memcontrol.c~mm-memcg-fix-mem_cgroup_swapout-for-thps
+++ a/mm/memcontrol.c
@@ -6044,7 +6044,7 @@ void mem_cgroup_swapout(struct page *pag
memcg_check_events(memcg, page);
if (!mem_cgroup_is_root(memcg))
- css_put(&memcg->css);
+ css_put_many(&memcg->css, nr_entries);
}
/**
_