From: Xiongwei Song <xiongwei.song@windriver.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@windriver.com>
---
 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

On 5/31/22 02:55, sxwjean@me.com wrote:
> From: Xiongwei Song <xiongwei.song@windriver.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@windriver.com>

Thanks, added to slab/for-5.20/cleanup

> ---
>  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;

On Tue, May 31, 2022 at 08:55:50AM +0800, sxwjean@me.com wrote:
> From: Xiongwei Song <xiongwei.song@windriver.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@windriver.com>

Reviewed-by: Muchun Song <songmuchun@bytedance.com>

Thanks.

On Tue, May 31, 2022 at 10:41 AM Muchun Song <songmuchun@bytedance.com> wrote:
>
> On Tue, May 31, 2022 at 08:55:50AM +0800, sxwjean@me.com wrote:
> > From: Xiongwei Song <xiongwei.song@windriver.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@windriver.com>
>
> Reviewed-by: Muchun Song <songmuchun@bytedance.com>

Thanks Muchun.

>
> Thanks.
>