1 files changed, 2 insertions, 4 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f4ede99c8b9b..8a79a6f0f029 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1601,7 +1601,6 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
                          * There is a small race that "from" or "to" can be
                          * freed by rmdir, so we use css_tryget().
                          */
-                        rcu_read_lock();
                         from = mc.from;
                         to = mc.to;
                         if (from && css_tryget(&from->css)) {
@@ -1622,7 +1621,6 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
                                         do_continue = (to == mem_over_limit);
                                 css_put(&to->css);
                         }
-                        rcu_read_unlock();
                         if (do_continue) {
                                 DEFINE_WAIT(wait);
                                 prepare_to_wait(&mc.waitq, &wait,
@@ -2429,11 +2427,11 @@ int mem_cgroup_prepare_migration(struct page *page, struct mem_cgroup **ptr)
         }
         unlock_page_cgroup(pc);
 
+        *ptr = mem;
         if (mem) {
-                ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false);
+                ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, ptr, false);
                 css_put(&mem->css);
         }
-        *ptr = mem;
         return ret;
 }