From a8c0f9a41f88da703ade33f9c1626a55c786e8bb Mon Sep 17 00:00:00 2001 From: Pekka Enberg Date: Sat, 25 Mar 2006 03:06:42 -0800 Subject: [PATCH] [PATCH] slab: introduce kmem_cache_zalloc allocator Introduce a memory-zeroing variant of kmem_cache_alloc. The allocator already exits in XFS and there are potential users for it so this patch makes the allocator available for the general public. Signed-off-by: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/slab.h | 2 ++ mm/slab.c | 17 +++++++++++++++++ mm/slob.c | 10 ++++++++++ 3 files changed, 29 insertions(+) diff --git a/include/linux/slab.h b/include/linux/slab.h index f88e08a5802..1216b09e07b 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -64,6 +64,7 @@ extern kmem_cache_t *kmem_cache_create(const char *, size_t, size_t, unsigned lo extern int kmem_cache_destroy(kmem_cache_t *); extern int kmem_cache_shrink(kmem_cache_t *); extern void *kmem_cache_alloc(kmem_cache_t *, gfp_t); +extern void *kmem_cache_zalloc(struct kmem_cache *, gfp_t); extern void kmem_cache_free(kmem_cache_t *, void *); extern unsigned int kmem_cache_size(kmem_cache_t *); extern const char *kmem_cache_name(kmem_cache_t *); @@ -156,6 +157,7 @@ struct kmem_cache *kmem_cache_create(const char *c, size_t, size_t, void (*)(void *, struct kmem_cache *, unsigned long)); int kmem_cache_destroy(struct kmem_cache *c); void *kmem_cache_alloc(struct kmem_cache *c, gfp_t flags); +void *kmem_cache_zalloc(struct kmem_cache *, gfp_t); void kmem_cache_free(struct kmem_cache *c, void *b); const char *kmem_cache_name(struct kmem_cache *); void *kmalloc(size_t size, gfp_t flags); diff --git a/mm/slab.c b/mm/slab.c index a5047161084..6f5aeebd430 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -3107,6 +3107,23 @@ void *kmem_cache_alloc(struct kmem_cache *cachep, gfp_t flags) } EXPORT_SYMBOL(kmem_cache_alloc); +/** + * kmem_cache_alloc - Allocate an object. The memory is set to zero. + * @cache: The cache to allocate from. + * @flags: See kmalloc(). + * + * Allocate an object from this cache and set the allocated memory to zero. + * The flags are only relevant if the cache has no available objects. + */ +void *kmem_cache_zalloc(struct kmem_cache *cache, gfp_t flags) +{ + void *ret = __cache_alloc(cache, flags, __builtin_return_address(0)); + if (ret) + memset(ret, 0, obj_size(cache)); + return ret; +} +EXPORT_SYMBOL(kmem_cache_zalloc); + /** * kmem_ptr_validate - check if an untrusted pointer might * be a slab entry. diff --git a/mm/slob.c b/mm/slob.c index a1f42bdc024..9bcc7e2cabf 100644 --- a/mm/slob.c +++ b/mm/slob.c @@ -294,6 +294,16 @@ void *kmem_cache_alloc(struct kmem_cache *c, gfp_t flags) } EXPORT_SYMBOL(kmem_cache_alloc); +void *kmem_cache_zalloc(struct kmem_cache *c, gfp_t flags) +{ + void *ret = kmem_cache_alloc(c, flags); + if (ret) + memset(ret, 0, c->size); + + return ret; +} +EXPORT_SYMBOL(kmem_cache_zalloc); + void kmem_cache_free(struct kmem_cache *c, void *b) { if (c->dtor)