linux-kernel - [PATCH v2] mm/slub: Simplify __kmem_cache

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Message-Id: <20220603143555.41914-1-sxwjean@me.com>
Date:   Fri,  3 Jun 2022 22:35:55 +0800
From:   sxwjean@...com
To:     cl@...ux.com, penberg@...nel.org, rientjes@...gle.com,
        iamjoonsoo.kim@....com, akpm@...ux-foundation.org, vbabka@...e.cz,
        roman.gushchin@...ux.dev, 42.hyeyoo@...il.com,
        songmuchun@...edance.com
Cc:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        Xiongwei Song <xiongwei.song@...driver.com>
Subject: [PATCH v2] mm/slub: Simplify __kmem_cache_alias()

From: Xiongwei Song <xiongwei.song@...driver.com>

There is no need to do anything if sysfs_slab_alias() return nonzero
value after getting a mergeable cache.

Signed-off-by: Xiongwei Song <xiongwei.song@...driver.com>
Reviewed-by: Muchun Song <songmuchun@...edance.com>
---
v2: Collect Reviewed-by tag from Muchun.
---
 mm/slub.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index d8d5abf49f5f..9444277d669a 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4861,6 +4861,9 @@ __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
 
 	s = find_mergeable(size, align, flags, name, ctor);
 	if (s) {
+		if (sysfs_slab_alias(s, name))
+			return NULL;
+
 		s->refcount++;
 
 		/*
@@ -4869,11 +4872,6 @@ __kmem_cache_alias(const char *name, unsigned int size, unsigned int align,
 		 */
 		s->object_size = max(s->object_size, size);
 		s->inuse = max(s->inuse, ALIGN(size, sizeof(void *)));
-
-		if (sysfs_slab_alias(s, name)) {
-			s->refcount--;
-			s = NULL;
-		}
 	}
 
 	return s;
-- 
2.30.2