Re: [PATCH 04/12] mm, slub: retain no free slabs on partial list with CONFIG_SLUB_TINY

[Hyeonggon Yoo]

On Mon, Nov 21, 2022 at 06:11:54PM +0100, Vlastimil Babka wrote:
> SLUB will leave a number of slabs on the partial list even if they are
> empty, to avoid some slab freeing and reallocation. The goal of
> CONFIG_SLUB_TINY is to minimize memory overhead, so set the limits to 0
> for immediate slab page freeing.
> 
> Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
> ---
>  mm/slub.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/mm/slub.c b/mm/slub.c
> index ab085aa2f1f0..917b79278bad 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -241,6 +241,7 @@ static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
>  /* Enable to log cmpxchg failures */
>  #undef SLUB_DEBUG_CMPXCHG
>  
> +#ifndef CONFIG_SLUB_TINY
>  /*
>   * Minimum number of partial slabs. These will be left on the partial
>   * lists even if they are empty. kmem_cache_shrink may reclaim them.
> @@ -253,6 +254,10 @@ static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
>   * sort the partial list by the number of objects in use.
>   */
>  #define MAX_PARTIAL 10
> +#else
> +#define MIN_PARTIAL 0
> +#define MAX_PARTIAL 0
> +#endif
>  
>  #define DEBUG_DEFAULT_FLAGS (SLAB_CONSISTENCY_CHECKS | SLAB_RED_ZONE | \
>  				SLAB_POISON | SLAB_STORE_USER)
> -- 
> 2.38.1
> 

Reviewed-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>

-- 
Thanks,
Hyeonggon