slab: replace smp_read_barrier_depends() with lockless_dereference()

Recently lockless_dereference() was added which can be used in place of hard-coding smp_read_barrier_depends(). The following PATCH makes the change. Signed-off-by: Pranith Kumar <[email protected]> Cc: "Paul E. McKenney" <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: David Rientjes <[email protected]> Cc: Joonsoo Kim <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
henryhallam · Dec 11, 2014 · 8df0c2d · 8df0c2d
1 parent c871ac4
commit 8df0c2d
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/mm/slab.h b/mm/slab.h
@@ -209,15 +209,15 @@ cache_from_memcg_idx(struct kmem_cache *s, int idx)
 
 	rcu_read_lock();
 	params = rcu_dereference(s->memcg_params);
-	cachep = params->memcg_caches[idx];
-	rcu_read_unlock();
 
 	/*
 	 * 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();
+	cachep = lockless_dereference(params->memcg_caches[idx]);
+	rcu_read_unlock();
+
 	return cachep;
 }