slub: clarify kmem_cache_refill_sheaf() comments

In the in-place refill case, some objects may already have been added
before the function returns -ENOMEM.
Clarify this behavior and polish the rest of the comment for readability.

Acked-by: Harry Yoo (Oracle) <harry@kernel.org>
Signed-off-by: Hao Li <hao.li@linux.dev>
Link: https://patch.msgid.link/20260407120018.42692-1-hao.li@linux.dev
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>

diff --git a/mm/slub.c b/mm/slub.c
index f896cdb4138351bed57c7b0d82034013551b3217..98d473f5c70185a9a33f0c56ac6550af45123cff 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -5120,12 +5120,15 @@ void kmem_cache_return_sheaf(struct kmem_cache *s, gfp_t gfp,
 }
 
 /*
- * refill a sheaf previously returned by kmem_cache_prefill_sheaf to at least
- * the given size
+ * Refill a sheaf previously returned by kmem_cache_prefill_sheaf to at least
+ * the given size.
  *
- * the sheaf might be replaced by a new one when requesting more than
- * s->sheaf_capacity objects if such replacement is necessary, but the refill
- * fails (returning -ENOMEM), the existing sheaf is left intact
+ * Return: 0 on success. The sheaf will contain at least @size objects.
+ * The sheaf might have been replaced with a new one if more than
+ * sheaf->capacity objects are requested.
+ *
+ * Return: -ENOMEM on failure. Some objects might have been added to the sheaf
+ * but the sheaf will not be replaced.
  *
  * In practice we always refill to full sheaf's capacity.
  */