[RFC 2/2] mm, slub: add missing kmem_cache_debug() checks

[Vlastimil Babka]

Some debugging checks in SLUB are not hidden behind kmem_cache_debug() check.
Add the check so that those places can also benefit from reduced overhead
thanks to the the static key added by the previous patch.

Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
---
 mm/slub.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/mm/slub.c b/mm/slub.c
index 398e53e16e2e..9d1b0e5e8593 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1086,6 +1086,13 @@ static inline void dec_slabs_node(struct kmem_cache *s, int node, int objects)
 static void setup_object_debug(struct kmem_cache *s, struct page *page,
 								void *object)
 {
+	/*
+	 * __OBJECT_POISON implies SLAB_POISON which is covered by
+	 * kmem_cache_debug()
+	 */
+	if (!kmem_cache_debug(s))
+		return;
+
 	if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON)))
 		return;
 
@@ -1095,6 +1102,9 @@ static void setup_object_debug(struct kmem_cache *s, struct page *page,
 
 static void setup_page_debug(struct kmem_cache *s, void *addr, int order)
 {
+	if (!kmem_cache_debug(s))
+		return;
+
 	if (!(s->flags & SLAB_POISON))
 		return;
 
@@ -1734,7 +1744,7 @@ static void __free_slab(struct kmem_cache *s, struct page *page)
 	int order = compound_order(page);
 	int pages = 1 << order;
 
-	if (s->flags & SLAB_CONSISTENCY_CHECKS) {
+	if (kmem_cache_debug(s) && s->flags & SLAB_CONSISTENCY_CHECKS) {
 		void *p;
 
 		slab_pad_check(s, page);
-- 
2.21.0