memcg: remove redundant check in move_task()

It's guaranteed by cgroup that old_cgrp != cgrp.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 3 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index fba566c51322..7056c3bdb478 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1168,9 +1168,6 @@ static void mem_cgroup_move_task(struct cgroup_subsys *ss,
         mem = mem_cgroup_from_cont(cont);
         old_mem = mem_cgroup_from_cont(old_cont);
 
-        if (mem == old_mem)
-                goto out;
-
         /*
          * Only thread group leaders are allowed to migrate, the mm_struct is
          * in effect owned by the leader