[PATCH] slab: remove unused SL_CPU slab_stat_type

[PATCH] slab: remove unused SL_CPU slab_stat_type

[Seongjun Hong]

Since the removal of the per-cpu slab in commit 32c894c7274b ("slab:
remove struct kmem_cache_cpu"), show_slab_objects() no longer has a
branch handling SO_CPU, so cpu_slabs_show() always produces "0".

Emit "0\n" directly instead, matching the sibling cpu_partial and
slabs_cpu_partial stubs, and remove the now-unused SO_CPU macro and
SL_CPU enum value.

No functional change intended; the cpu_slabs sysfs attribute continues
to read 0.

Signed-off-by: Seongjun Hong <hsj0512@snu.ac.kr>
---
 mm/slub.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index 9ec774dc7009..f2eb60ce0d23 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -8992,14 +8992,12 @@ static void process_slab(struct loc_track *t, struct kmem_cache *s,
 enum slab_stat_type {
 	SL_ALL,			/* All slabs */
 	SL_PARTIAL,		/* Only partially allocated slabs */
-	SL_CPU,			/* Only slabs used for cpu caches */
 	SL_OBJECTS,		/* Determine allocated objects not slabs */
 	SL_TOTAL		/* Determine object capacity not slabs */
 };
 
 #define SO_ALL		(1 << SL_ALL)
 #define SO_PARTIAL	(1 << SL_PARTIAL)
-#define SO_CPU		(1 << SL_CPU)
 #define SO_OBJECTS	(1 << SL_OBJECTS)
 #define SO_TOTAL	(1 << SL_TOTAL)
 
@@ -9188,7 +9186,7 @@ SLAB_ATTR_RO(partial);
 
 static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
 {
-	return show_slab_objects(s, buf, SO_CPU);
+	return sysfs_emit(buf, "0\n");
 }
 SLAB_ATTR_RO(cpu_slabs);
 
-- 
2.43.0

Re: [PATCH] slab: remove unused SL_CPU slab_stat_type

[Harry Yoo]

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On 7/1/26 11:06 PM, Seongjun Hong wrote:
> Since the removal of the per-cpu slab in commit 32c894c7274b ("slab:
> remove struct kmem_cache_cpu"), show_slab_objects() no longer has a
> branch handling SO_CPU, so cpu_slabs_show() always produces "0".
> 
> Emit "0\n" directly instead, matching the sibling cpu_partial and
> slabs_cpu_partial stubs, and remove the now-unused SO_CPU macro and
> SL_CPU enum value.
> 
> No functional change intended; the cpu_slabs sysfs attribute continues
> to read 0.
> 
> Signed-off-by: Seongjun Hong <hsj0512@snu.ac.kr>
> ---

Reviewed-by: Harry Yoo (Oracle) <harry@kernel.org>

-- 
Cheers,
Harry / Hyeonggon

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Re: [PATCH] slab: remove unused SL_CPU slab_stat_type

[Hao Li]

On Wed, Jul 01, 2026 at 02:06:33PM +0000, Seongjun Hong wrote:
> Since the removal of the per-cpu slab in commit 32c894c7274b ("slab:
> remove struct kmem_cache_cpu"), show_slab_objects() no longer has a
> branch handling SO_CPU, so cpu_slabs_show() always produces "0".
> 
> Emit "0\n" directly instead, matching the sibling cpu_partial and
> slabs_cpu_partial stubs, and remove the now-unused SO_CPU macro and
> SL_CPU enum value.
> 
> No functional change intended; the cpu_slabs sysfs attribute continues
> to read 0.
> 
> Signed-off-by: Seongjun Hong <hsj0512@snu.ac.kr>
> ---

Reviewed-by: Hao Li <hao.li@linux.dev>

-- 
Thanks,
Hao

Re: [PATCH] slab: remove unused SL_CPU slab_stat_type

[Vlastimil Babka (SUSE)]

On 7/1/26 16:06, Seongjun Hong wrote:
> Since the removal of the per-cpu slab in commit 32c894c7274b ("slab:
> remove struct kmem_cache_cpu"), show_slab_objects() no longer has a
> branch handling SO_CPU, so cpu_slabs_show() always produces "0".
> 
> Emit "0\n" directly instead, matching the sibling cpu_partial and
> slabs_cpu_partial stubs, and remove the now-unused SO_CPU macro and
> SL_CPU enum value.
> 
> No functional change intended; the cpu_slabs sysfs attribute continues
> to read 0.
> 
> Signed-off-by: Seongjun Hong <hsj0512@snu.ac.kr>

Applied to slab/for-next, thanks!

> ---
>  mm/slub.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/mm/slub.c b/mm/slub.c
> index 9ec774dc7009..f2eb60ce0d23 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -8992,14 +8992,12 @@ static void process_slab(struct loc_track *t, struct kmem_cache *s,
>  enum slab_stat_type {
>  	SL_ALL,			/* All slabs */
>  	SL_PARTIAL,		/* Only partially allocated slabs */
> -	SL_CPU,			/* Only slabs used for cpu caches */
>  	SL_OBJECTS,		/* Determine allocated objects not slabs */
>  	SL_TOTAL		/* Determine object capacity not slabs */
>  };
>  
>  #define SO_ALL		(1 << SL_ALL)
>  #define SO_PARTIAL	(1 << SL_PARTIAL)
> -#define SO_CPU		(1 << SL_CPU)
>  #define SO_OBJECTS	(1 << SL_OBJECTS)
>  #define SO_TOTAL	(1 << SL_TOTAL)
>  
> @@ -9188,7 +9186,7 @@ SLAB_ATTR_RO(partial);
>  
>  static ssize_t cpu_slabs_show(struct kmem_cache *s, char *buf)
>  {
> -	return show_slab_objects(s, buf, SO_CPU);
> +	return sysfs_emit(buf, "0\n");
>  }
>  SLAB_ATTR_RO(cpu_slabs);
>