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

From: Hyeonggon Yoo
Date: Thu Nov 24 2022 - 06:39:09 EST


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