Add a comment to clarify why we don't call kobject_put() when
kobject_init_and_add() fails in sysfs_slab_add().

Per commit 2420baa8e046 ("mm/slab: Allow cache creation to proceed
even if sysfs registration fails"), sysfs failures are treated as
non-fatal and the cache continues to be used. Calling kobject_put()
would trigger slab_kmem_cache_release() which frees the entire
cache structure, so we intentionally skip it.

Suggested-by: Hyeonggon Kim <pictureone@kakao.com>
Signed-off-by: Hongling Zeng <zenghongling@kylinos.cn>
---
 mm/slub.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/mm/slub.c b/mm/slub.c
index 9ec774dc7009..edc822d7d9ea 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -9690,6 +9690,11 @@ static int sysfs_slab_add(struct kmem_cache *s)
 
 	s->kobj.kset = kset;
 	err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name);
+	/*
+	 * Intentionally skip kobject_put(). See commit 2420baa8e046
+	 * ("mm/slab: Allow cache creation to proceed even if sysfs
+	 * registration fails")
+	 */
 	if (err)
 		goto out;
 
-- 
2.25.1