1 files changed, 11 insertions, 1 deletions

diff --git a/mm/slab.h b/mm/slab.h
index 0859c4241ba1..72d1f9df71bd 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -163,9 +163,19 @@ static inline const char *cache_name(struct kmem_cache *s)
 static inline struct kmem_cache *
 cache_from_memcg_idx(struct kmem_cache *s, int idx)
 {
+        struct kmem_cache *cachep;
+
         if (!s->memcg_params)
                 return NULL;
-        return s->memcg_params->memcg_caches[idx];
+        cachep = s->memcg_params->memcg_caches[idx];
+
+        /*
+         * Make sure we will access the up-to-date value. The code updating
+         * memcg_caches issues a write barrier to match this (see
+         * memcg_register_cache()).
+         */
+        smp_read_barrier_depends();
+        return cachep;
 }
 
 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)