[PATCH] mm/slub: make add_full() condition more explicit

[wuyun.wu]

From: Abel Wu <wuyun.wu@xxxxxxxxxx>

The commit below is incomplete, as it didn't handle the add_full() part.
commit a4d3f8916c65 ("slub: remove useless kmem_cache_debug() before remove_full()")

This patch checks for SLAB_STORE_USER instead of kmem_cache_debug(),
since that should be the only context in which we need the list_lock for
add_full().

Signed-off-by: Abel Wu <wuyun.wu@xxxxxxxxxx>
---
 mm/slub.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mm/slub.c b/mm/slub.c
index f226d66408ee..df93a5a0e9a4 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2182,7 +2182,8 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page,
 		}
 	} else {
 		m = M_FULL;
-		if (kmem_cache_debug(s) && !lock) {
+#ifdef CONFIG_SLUB_DEBUG
+		if ((s->flags & SLAB_STORE_USER) && !lock) {
 			lock = 1;
 			/*
 			 * This also ensures that the scanning of full
@@ -2191,6 +2192,7 @@ static void deactivate_slab(struct kmem_cache *s, struct page *page,
 			 */
 			spin_lock(&n->list_lock);
 		}
+#endif
 	}
 
 	if (l != m) {
-- 
2.28.0.windows.1