Re: [PATCH v2 14/15] slab: remove kmem_cache_create_rcu()

[Mike Rapoport <rppt@kernel.org>]

On Tue, Sep 03, 2024 at 04:20:55PM +0200, Christian Brauner wrote:
> Since we have kmem_cache_setup() and have ported kmem_cache_create_rcu()
> users over to it is unused and can be removed.
> 
> Signed-off-by: Christian Brauner <brauner@kernel.org>

Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>

> ---
>  include/linux/slab.h |  3 ---
>  mm/slab_common.c     | 43 -------------------------------------------
>  2 files changed, 46 deletions(-)
> 
> diff --git a/include/linux/slab.h b/include/linux/slab.h
> index 4292d67094c3..1176b30cd4b2 100644
> --- a/include/linux/slab.h
> +++ b/include/linux/slab.h
> @@ -270,9 +270,6 @@ struct kmem_cache *kmem_cache_create_usercopy(const char *name,
>  			slab_flags_t flags,
>  			unsigned int useroffset, unsigned int usersize,
>  			void (*ctor)(void *));
> -struct kmem_cache *kmem_cache_create_rcu(const char *name, unsigned int size,
> -					 unsigned int freeptr_offset,
> -					 slab_flags_t flags);
>  
>  #define kmem_cache_create(__name, __object_size, __args, ...)           \
>  	_Generic((__args),                                              \
> diff --git a/mm/slab_common.c b/mm/slab_common.c
> index 418459927670..9133b9fafcb1 100644
> --- a/mm/slab_common.c
> +++ b/mm/slab_common.c
> @@ -420,49 +420,6 @@ struct kmem_cache *__kmem_cache_create(const char *name, unsigned int size,
>  }
>  EXPORT_SYMBOL(__kmem_cache_create);
>  
> -/**
> - * kmem_cache_create_rcu - Create a SLAB_TYPESAFE_BY_RCU cache.
> - * @name: A string which is used in /proc/slabinfo to identify this cache.
> - * @size: The size of objects to be created in this cache.
> - * @freeptr_offset: The offset into the memory to the free pointer
> - * @flags: SLAB flags
> - *
> - * Cannot be called within an interrupt, but can be interrupted.
> - *
> - * See kmem_cache_create() for an explanation of possible @flags.
> - *
> - * By default SLAB_TYPESAFE_BY_RCU caches place the free pointer outside
> - * of the object. This might cause the object to grow in size. Callers
> - * that have a reason to avoid this can specify a custom free pointer
> - * offset in their struct where the free pointer will be placed.
> - *
> - * Note that placing the free pointer inside the object requires the
> - * caller to ensure that no fields are invalidated that are required to
> - * guard against object recycling (See SLAB_TYPESAFE_BY_RCU for
> - * details.).
> - *
> - * Using zero as a value for @freeptr_offset is valid. To request no
> - * offset UINT_MAX must be specified.
> - *
> - * Note that @ctor isn't supported with custom free pointers as a @ctor
> - * requires an external free pointer.
> - *
> - * Return: a pointer to the cache on success, NULL on failure.
> - */
> -struct kmem_cache *kmem_cache_create_rcu(const char *name, unsigned int size,
> -					 unsigned int freeptr_offset,
> -					 slab_flags_t flags)
> -{
> -	struct kmem_cache_args kmem_args = {
> -		.freeptr_offset		= freeptr_offset,
> -		.use_freeptr_offset	= true,
> -	};
> -
> -	return __kmem_cache_create_args(name, size, &kmem_args,
> -					flags | SLAB_TYPESAFE_BY_RCU);
> -}
> -EXPORT_SYMBOL(kmem_cache_create_rcu);
> -
>  static struct kmem_cache *kmem_buckets_cache __ro_after_init;
>  
>  /**
> 
> -- 
> 2.45.2
> 

-- 
Sincerely yours,
Mike.