slub: use __cmpxchg_double_slab() at interrupt disabled place

get_freelist(), unfreeze_partials() are only called with interrupt disabled,
so __cmpxchg_double_slab() is suitable.
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <js1304@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

mm/slub.c

@@ -1872,7 +1872,11 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page, void *freel
 	}
 }
 
-/* Unfreeze all the cpu partial slabs */
+/*
+ * Unfreeze all the cpu partial slabs.
+ *
+ * This function must be called with interrupt disabled.
+ */
 static void unfreeze_partials(struct kmem_cache *s)
 {
 	struct kmem_cache_node *n = NULL;
@@ -1928,7 +1932,7 @@ static void unfreeze_partials(struct kmem_cache *s)
 				l = m;
 			}
 
-		} while (!cmpxchg_double_slab(s, page,
+		} while (!__cmpxchg_double_slab(s, page,
 				old.freelist, old.counters,
 				new.freelist, new.counters,
 				"unfreezing slab"));
@@ -2165,6 +2169,8 @@ static inline void *new_slab_objects(struct kmem_cache *s, gfp_t flags,
  * The page is still frozen if the return value is not NULL.
  *
  * If this function returns NULL then the page has been unfrozen.
+ *
+ * This function must be called with interrupt disabled.
  */
 static inline void *get_freelist(struct kmem_cache *s, struct page *page)
 {
@@ -2182,7 +2188,7 @@ static inline void *get_freelist(struct kmem_cache *s, struct page *page)
 		new.inuse = page->objects;
 		new.frozen = freelist != NULL;
 
-	} while (!cmpxchg_double_slab(s, page,
+	} while (!__cmpxchg_double_slab(s, page,
 		freelist, counters,
 		NULL, new.counters,
 		"get_freelist"));