Re: [PATCH 1/1] mm, slab: move prepare_slab_obj_exts_hook under CONFIG_MEM_ALLOC_PROFILING

[Vlastimil Babka <vbabka@suse.cz>]

On 7/11/24 7:02 PM, Suren Baghdasaryan wrote:
> The only place prepare_slab_obj_exts_hook() is currently being used is
> from alloc_tagging_slab_alloc_hook() when CONFIG_MEM_ALLOC_PROFILING=y.
> Move its definition under CONFIG_MEM_ALLOC_PROFILING to prevent unused
> function warning for CONFIG_SLAB_OBJ_EXT=n case.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202407050845.zNONqauD-lkp@intel.com/

Hm so that's a mainline report, but being a clang-only W=1 warning I think
it can just wait for the merge window and no need for last-minute 6.10 fix.

> Signed-off-by: Suren Baghdasaryan <surenb@google.com>
> Cc: Vlastimil Babka <vbabka@suse.cz>
> ---
> Applied over slab/for-next because of the refactoring [1] in that branch.

And thus took it there. thanks.

> 
> [1] 302a3ea38aec ("mm, slab: move allocation tagging code in the alloc path into a hook")
> 
>  mm/slub.c | 48 +++++++++++++++++++++---------------------------
>  1 file changed, 21 insertions(+), 27 deletions(-)
> 
> diff --git a/mm/slub.c b/mm/slub.c
> index ce39544acf7c..829a1f08e8a2 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -2027,6 +2027,27 @@ static inline bool need_slab_obj_ext(void)
>  	return false;
>  }
>  
> +#else /* CONFIG_SLAB_OBJ_EXT */
> +
> +static int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
> +			       gfp_t gfp, bool new_slab)
> +{
> +	return 0;
> +}
> +
> +static inline void free_slab_obj_exts(struct slab *slab)
> +{
> +}
> +
> +static inline bool need_slab_obj_ext(void)
> +{
> +	return false;
> +}
> +
> +#endif /* CONFIG_SLAB_OBJ_EXT */
> +
> +#ifdef CONFIG_MEM_ALLOC_PROFILING
> +
>  static inline struct slabobj_ext *
>  prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p)
>  {
> @@ -2051,33 +2072,6 @@ prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p)
>  	return slab_obj_exts(slab) + obj_to_index(s, slab, p);
>  }
>  
> -#else /* CONFIG_SLAB_OBJ_EXT */
> -
> -static int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s,
> -			       gfp_t gfp, bool new_slab)
> -{
> -	return 0;
> -}
> -
> -static inline void free_slab_obj_exts(struct slab *slab)
> -{
> -}
> -
> -static inline bool need_slab_obj_ext(void)
> -{
> -	return false;
> -}
> -
> -static inline struct slabobj_ext *
> -prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p)
> -{
> -	return NULL;
> -}
> -
> -#endif /* CONFIG_SLAB_OBJ_EXT */
> -
> -#ifdef CONFIG_MEM_ALLOC_PROFILING
> -
>  static inline void
>  alloc_tagging_slab_alloc_hook(struct kmem_cache *s, void *object, gfp_t flags)
>  {
> 
> base-commit: fe4e761669ab4d8b388fdb6e9dbe9a110eed8009