[PATCH] mm/slub: mark racy access on slab->freelist

From: linke li
Date: Sat Apr 27 2024 - 04:52:23 EST


In deactivate_slab(), slab->freelist can be changed concurrently. Mark
data race on slab->freelist as benign using READ_ONCE.

This patch is aimed at reducing the number of benign races reported by
KCSAN in order to focus future debugging effort on harmful races.

Signed-off-by: linke li <lilinke99@xxxxxx>
---
mm/slub.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/slub.c b/mm/slub.c
index 0d700f6ca547..bb0e05a321e9 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2813,7 +2813,7 @@ static void deactivate_slab(struct kmem_cache *s, struct slab *slab,
struct slab new;
struct slab old;

- if (slab->freelist) {
+ if (READ_ONCE(slab->freelist)) {
stat(s, DEACTIVATE_REMOTE_FREES);
tail = DEACTIVATE_TO_TAIL;
}
--
2.39.3 (Apple Git-146)