1 files changed, 13 insertions, 2 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 7bb14fdc780c..81b0ae8183d0 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -994,13 +994,24 @@ nomem:
 static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page)
 {
         struct mem_cgroup *mem;
+        struct page_cgroup *pc;
         swp_entry_t ent;
 
+        VM_BUG_ON(!PageLocked(page));
+
         if (!PageSwapCache(page))
                 return NULL;
 
-        ent.val = page_private(page);
-        mem = lookup_swap_cgroup(ent);
+        pc = lookup_page_cgroup(page);
+        /*
+         * Used bit of swapcache is solid under page lock.
+         */
+        if (PageCgroupUsed(pc))
+                mem = pc->mem_cgroup;
+        else {
+                ent.val = page_private(page);
+                mem = lookup_swap_cgroup(ent);
+        }
         if (!mem)
                 return NULL;
         if (!css_tryget(&mem->css))