From 16025177e1e16529451108faed257db95c7c9d6a Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Thu, 24 Oct 2013 10:07:46 +0900 Subject: [PATCH] slab: remove kmem_bufctl_t Now, we changed the management method of free objects of the slab and there is no need to use special value, BUFCTL_END, BUFCTL_FREE and BUFCTL_ACTIVE. So remove them. Acked-by: Andi Kleen Signed-off-by: Joonsoo Kim Signed-off-by: Pekka Enberg --- mm/slab.c | 42 +++++++++++------------------------------- 1 file changed, 11 insertions(+), 31 deletions(-) diff --git a/mm/slab.c b/mm/slab.c index 05fe37eb4a57..6ced1ccf8abb 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -163,27 +163,7 @@ */ static bool pfmemalloc_active __read_mostly; -/* - * kmem_bufctl_t: - * - * Bufctl's are used for linking objs within a slab - * linked offsets. - * - * This implementation relies on "struct page" for locating the cache & - * slab an object belongs to. - * This allows the bufctl structure to be small (one int), but limits - * the number of objects a slab (not a cache) can contain when off-slab - * bufctls are used. The limit is the size of the largest general cache - * that does not use off-slab slabs. - * For 32bit archs with 4 kB pages, is this 56. - * This is not serious, as it is only for large objects, when it is unwise - * to have too many per slab. - * Note: This limit can be raised by introducing a general cache whose size - * is less than 512 (PAGE_SIZE<<3), but greater than 256. - */ - -typedef unsigned int kmem_bufctl_t; -#define SLAB_LIMIT (((kmem_bufctl_t)(~0U))-3) +#define SLAB_LIMIT (((unsigned int)(~0U))-1) /* * struct slab @@ -197,7 +177,7 @@ struct slab { struct list_head list; void *s_mem; /* including colour offset */ unsigned int inuse; /* num of objs active in slab */ - kmem_bufctl_t free; + unsigned int free; }; }; @@ -613,7 +593,7 @@ static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep) static size_t slab_mgmt_size(size_t nr_objs, size_t align) { - return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align); + return ALIGN(sizeof(struct slab)+nr_objs*sizeof(unsigned int), align); } /* @@ -633,7 +613,7 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size, * slab is used for: * * - The struct slab - * - One kmem_bufctl_t for each object + * - One unsigned int for each object * - Padding to respect alignment of @align * - @buffer_size bytes for each object * @@ -658,7 +638,7 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size, * into account. */ nr_objs = (slab_size - sizeof(struct slab)) / - (buffer_size + sizeof(kmem_bufctl_t)); + (buffer_size + sizeof(unsigned int)); /* * This calculated number will be either the right @@ -2068,7 +2048,7 @@ static size_t calculate_slab_order(struct kmem_cache *cachep, * looping condition in cache_grow(). */ offslab_limit = size - sizeof(struct slab); - offslab_limit /= sizeof(kmem_bufctl_t); + offslab_limit /= sizeof(unsigned int); if (num > offslab_limit) break; @@ -2309,7 +2289,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) if (!cachep->num) return -E2BIG; - slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t) + slab_size = ALIGN(cachep->num * sizeof(unsigned int) + sizeof(struct slab), cachep->align); /* @@ -2324,7 +2304,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags) if (flags & CFLGS_OFF_SLAB) { /* really off slab. No need for manual alignment */ slab_size = - cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab); + cachep->num * sizeof(unsigned int) + sizeof(struct slab); #ifdef CONFIG_PAGE_POISONING /* If we're going to use the generic kernel_map_pages() @@ -2603,9 +2583,9 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, return slabp; } -static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp) +static inline unsigned int *slab_bufctl(struct slab *slabp) { - return (kmem_bufctl_t *) (slabp + 1); + return (unsigned int *) (slabp + 1); } static void cache_init_objs(struct kmem_cache *cachep, @@ -2684,7 +2664,7 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp, { unsigned int objnr = obj_to_index(cachep, slabp, objp); #if DEBUG - kmem_bufctl_t i; + unsigned int i; /* Verify that the slab belongs to the intended node */ WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid); -- 2.30.2