Re: [PATCH v2 10/21] mm/slab: move struct kmem_cache_cpu declaration to slub.c

Hyeonggon Yoo
2023-12-06T09:35:50Z

On Mon, Nov 20, 2023 at 07:34:21PM +0100, Vlastimil Babka wrote:
> Nothing outside SLUB itself accesses the struct kmem_cache_cpu fields so
> it does not need to be declared in slub_def.h. This allows also to move
> enum stat_item.
>
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
> ---
> include/linux/slub_def.h | 54 ------------------------------------------------
> mm/slub.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 54 insertions(+), 54 deletions(-)
>
> diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
> index deb90cf4bffb..a0229ea42977 100644
> --- a/include/linux/slub_def.h
> +++ b/include/linux/slub_def.h
> @@ -12,60 +12,6 @@
> #include <linux/reciprocal_div.h>
> #include <linux/local_lock.h>
>
> -enum stat_item {
> - ALLOC_FASTPATH, /* Allocation from cpu slab */
> - ALLOC_SLOWPATH, /* Allocation by getting a new cpu slab */
> - FREE_FASTPATH, /* Free to cpu slab */
> - FREE_SLOWPATH, /* Freeing not to cpu slab */
> - FREE_FROZEN, /* Freeing to frozen slab */
> - FREE_ADD_PARTIAL, /* Freeing moves slab to partial list */
> - FREE_REMOVE_PARTIAL, /* Freeing removes last object */
> - ALLOC_FROM_PARTIAL, /* Cpu slab acquired from node partial list */
> - ALLOC_SLAB, /* Cpu slab acquired from page allocator */
> - ALLOC_REFILL, /* Refill cpu slab from slab freelist */
> - ALLOC_NODE_MISMATCH, /* Switching cpu slab */
> - FREE_SLAB, /* Slab freed to the page allocator */
> - CPUSLAB_FLUSH, /* Abandoning of the cpu slab */
> - DEACTIVATE_FULL, /* Cpu slab was full when deactivated */
> - DEACTIVATE_EMPTY, /* Cpu slab was empty when deactivated */
> - DEACTIVATE_TO_HEAD, /* Cpu slab was moved to the head of partials */
> - DEACTIVATE_TO_TAIL, /* Cpu slab was moved to the tail of partials */
> - DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
> - DEACTIVATE_BYPASS, /* Implicit deactivation */
> - ORDER_FALLBACK, /* Number of times fallback was necessary */
> - CMPXCHG_DOUBLE_CPU_FAIL,/* Failure of this_cpu_cmpxchg_double */
> - CMPXCHG_DOUBLE_FAIL, /* Number of times that cmpxchg double did not match */
> - CPU_PARTIAL_ALLOC, /* Used cpu partial on alloc */
> - CPU_PARTIAL_FREE, /* Refill cpu partial on free */
> - CPU_PARTIAL_NODE, /* Refill cpu partial from node partial */
> - CPU_PARTIAL_DRAIN, /* Drain cpu partial to node partial */
> - NR_SLUB_STAT_ITEMS
> -};
> -
> -#ifndef CONFIG_SLUB_TINY
> -/*
> - * When changing the layout, make sure freelist and tid are still compatible
> - * with this_cpu_cmpxchg_double() alignment requirements.
> - */
> -struct kmem_cache_cpu {
> - union {
> - struct {
> - void **freelist; /* Pointer to next available object */
> - unsigned long tid; /* Globally unique transaction id */
> - };
> - freelist_aba_t freelist_tid;
> - };
> - struct slab *slab; /* The slab from which we are allocating */
> -#ifdef CONFIG_SLUB_CPU_PARTIAL
> - struct slab *partial; /* Partially allocated frozen slabs */
> -#endif
> - local_lock_t lock; /* Protects the fields above */
> -#ifdef CONFIG_SLUB_STATS
> - unsigned stat[NR_SLUB_STAT_ITEMS];
> -#endif
> -};
> -#endif /* CONFIG_SLUB_TINY */
> -
> #ifdef CONFIG_SLUB_CPU_PARTIAL
> #define slub_percpu_partial(c) ((c)->partial)
>
> diff --git a/mm/slub.c b/mm/slub.c
> index 3e01731783df..979932d046fd 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -330,6 +330,60 @@ static void debugfs_slab_add(struct kmem_cache *);
> static inline void debugfs_slab_add(struct kmem_cache *s) { }
> #endif
>
> +enum stat_item {
> + ALLOC_FASTPATH, /* Allocation from cpu slab */
> + ALLOC_SLOWPATH, /* Allocation by getting a new cpu slab */
> + FREE_FASTPATH, /* Free to cpu slab */
> + FREE_SLOWPATH, /* Freeing not to cpu slab */
> + FREE_FROZEN, /* Freeing to frozen slab */
> + FREE_ADD_PARTIAL, /* Freeing moves slab to partial list */
> + FREE_REMOVE_PARTIAL, /* Freeing removes last object */
> + ALLOC_FROM_PARTIAL, /* Cpu slab acquired from node partial list */
> + ALLOC_SLAB, /* Cpu slab acquired from page allocator */
> + ALLOC_REFILL, /* Refill cpu slab from slab freelist */
> + ALLOC_NODE_MISMATCH, /* Switching cpu slab */
> + FREE_SLAB, /* Slab freed to the page allocator */
> + CPUSLAB_FLUSH, /* Abandoning of the cpu slab */
> + DEACTIVATE_FULL, /* Cpu slab was full when deactivated */
> + DEACTIVATE_EMPTY, /* Cpu slab was empty when deactivated */
> + DEACTIVATE_TO_HEAD, /* Cpu slab was moved to the head of partials */
> + DEACTIVATE_TO_TAIL, /* Cpu slab was moved to the tail of partials */
> + DEACTIVATE_REMOTE_FREES,/* Slab contained remotely freed objects */
> + DEACTIVATE_BYPASS, /* Implicit deactivation */
> + ORDER_FALLBACK, /* Number of times fallback was necessary */
> + CMPXCHG_DOUBLE_CPU_FAIL,/* Failures of this_cpu_cmpxchg_double */
> + CMPXCHG_DOUBLE_FAIL, /* Failures of slab freelist update */
> + CPU_PARTIAL_ALLOC, /* Used cpu partial on alloc */
> + CPU_PARTIAL_FREE, /* Refill cpu partial on free */
> + CPU_PARTIAL_NODE, /* Refill cpu partial from node partial */
> + CPU_PARTIAL_DRAIN, /* Drain cpu partial to node partial */
> + NR_SLUB_STAT_ITEMS
> +};
> +
> +#ifndef CONFIG_SLUB_TINY
> +/*
> + * When changing the layout, make sure freelist and tid are still compatible
> + * with this_cpu_cmpxchg_double() alignment requirements.
> + */
> +struct kmem_cache_cpu {
> + union {
> + struct {
> + void **freelist; /* Pointer to next available object */
> + unsigned long tid; /* Globally unique transaction id */
> + };
> + freelist_aba_t freelist_tid;
> + };
> + struct slab *slab; /* The slab from which we are allocating */
> +#ifdef CONFIG_SLUB_CPU_PARTIAL
> + struct slab *partial; /* Partially allocated frozen slabs */
> +#endif
> + local_lock_t lock; /* Protects the fields above */
> +#ifdef CONFIG_SLUB_STATS
> + unsigned int stat[NR_SLUB_STAT_ITEMS];
> +#endif
> +};
> +#endif /* CONFIG_SLUB_TINY */
> +
> static inline void stat(const struct kmem_cache *s, enum stat_item si)
> {
> #ifdef CONFIG_SLUB_STATS

Looks good to me,
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>

>
> --
> 2.42.1
>
>