memcg: fix oops in mem_cgroup_shrink_usage

[linux-2.6-omap-h63xx.git] / mm / memcontrol.c

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index fba566c513220dcf8c30133a617e5d27328a23f2..0f1f7a7374bade23cf0052719a349a97322c5af4 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -796,6 +796,8 @@ int mem_cgroup_shrink_usage(struct mm_struct *mm, gfp_t gfp_mask)
 
        if (mem_cgroup_subsys.disabled)
                return 0;
+       if (!mm)
+               return 0;
 
        rcu_read_lock();
        mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
@@ -1168,9 +1170,6 @@ 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