Re: [PATCH 1/3] mm, slab: deprecate SLAB_MEM_SPREAD flag

[Chengming Zhou <chengming.zhou@linux.dev>]

On 2024/2/21 00:58, Vlastimil Babka wrote:
> The SLAB_MEM_SPREAD flag used to be implemented in SLAB, which was
> removed.  SLUB instead relies on the page allocator's NUMA policies.
> Change the flag's value to 0 to free up the value it had, and mark it
> for full removal once all users are gone.
> 
> Reported-by: Steven Rostedt <rostedt@goodmis.org>
> Closes: https://lore.kernel.org/all/20240131172027.10f64405@gandalf.local.home/
> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>

Thanks!

> ---
>  include/linux/slab.h | 5 +++--
>  mm/slab.h            | 1 -
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index b5f5ee8308d0..6252f44115c2 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -96,8 +96,6 @@
>   */
>  /* Defer freeing slabs to RCU */
>  #define SLAB_TYPESAFE_BY_RCU	((slab_flags_t __force)0x00080000U)
> -/* Spread some memory over cpuset */
> -#define SLAB_MEM_SPREAD		((slab_flags_t __force)0x00100000U)
>  /* Trace allocations and frees */
>  #define SLAB_TRACE		((slab_flags_t __force)0x00200000U)
>  
> @@ -164,6 +162,9 @@
>  #endif
>  #define SLAB_TEMPORARY		SLAB_RECLAIM_ACCOUNT	/* Objects are short-lived */
>  
> +/* Obsolete unused flag, to be removed */
> +#define SLAB_MEM_SPREAD		0
> +
>  /*
>   * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
>   *
> diff --git a/mm/slab.h b/mm/slab.h
> index 54deeb0428c6..f4534eefb35d 100644
> --- a/mm/slab.h
> +++ b/mm/slab.h
> @@ -469,7 +469,6 @@ static inline bool is_kmalloc_cache(struct kmem_cache *s)
>  			      SLAB_STORE_USER | \
>  			      SLAB_TRACE | \
>  			      SLAB_CONSISTENCY_CHECKS | \
> -			      SLAB_MEM_SPREAD | \
>  			      SLAB_NOLEAKTRACE | \
>  			      SLAB_RECLAIM_ACCOUNT | \
>  			      SLAB_TEMPORARY | \
>