mm, memcg: fix mem_cgroup_swapout() for THPs

commit d08afa149a upstream.

Commit d6810d7300 ("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@google.com
Fixes: d6810d7300 ("memcg, THP, swap: make mem_cgroup_swapout() support THP")
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Shakeel Butt 2017-11-29 16:11:15 -08:00 committed by Greg Kroah-Hartman
parent 13167cf417
commit d983b6251c

View file

@ -6044,7 +6044,7 @@ void mem_cgroup_swapout(struct page *page, swp_entry_t entry)
memcg_check_events(memcg, page);
if (!mem_cgroup_is_root(memcg))
css_put(&memcg->css);
css_put_many(&memcg->css, nr_entries);
}
/**