From 8fea4e96a8f29ccc34c244f54574680ce9b43631 Mon Sep 17 00:00:00 2001 From: Pekka Enberg Date: Wed, 22 Mar 2006 00:08:10 -0800 Subject: [PATCH] [PATCH] slab: object to index mapping cleanup Clean up the object to index mapping that has been spread around mm/slab.c. Signed-off-by: Pekka Enberg Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/slab.c | 34 +++++++++++++++++++++++----------- 1 file changed, 23 insertions(+), 11 deletions(-) diff --git a/mm/slab.c b/mm/slab.c index 5988adf010c5..3d18b711ab82 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -609,6 +609,18 @@ static inline struct slab *virt_to_slab(const void *obj) return page_get_slab(page); } +static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab, + unsigned int idx) +{ + return slab->s_mem + cache->buffer_size * idx; +} + +static inline unsigned int obj_to_index(struct kmem_cache *cache, + struct slab *slab, void *obj) +{ + return (unsigned)(obj - slab->s_mem) / cache->buffer_size; +} + /* These are the default caches for kmalloc. Custom caches can have other sizes. */ struct cache_sizes malloc_sizes[] = { #define CACHE(x) { .cs_size = (x) }, @@ -1568,18 +1580,18 @@ static void check_poison_obj(struct kmem_cache *cachep, void *objp) * exist: */ struct slab *slabp = virt_to_slab(objp); - int objnr; + unsigned int objnr; - objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size; + objnr = obj_to_index(cachep, slabp, objp); if (objnr) { - objp = slabp->s_mem + (objnr - 1) * cachep->buffer_size; + objp = index_to_obj(cachep, slabp, objnr - 1); realobj = (char *)objp + obj_offset(cachep); printk(KERN_ERR "Prev obj: start=%p, len=%d\n", realobj, size); print_objinfo(cachep, objp, 2); } if (objnr + 1 < cachep->num) { - objp = slabp->s_mem + (objnr + 1) * cachep->buffer_size; + objp = index_to_obj(cachep, slabp, objnr + 1); realobj = (char *)objp + obj_offset(cachep); printk(KERN_ERR "Next obj: start=%p, len=%d\n", realobj, size); @@ -1598,7 +1610,7 @@ static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp) { int i; for (i = 0; i < cachep->num; i++) { - void *objp = slabp->s_mem + cachep->buffer_size * i; + void *objp = index_to_obj(cachep, slabp, i); if (cachep->flags & SLAB_POISON) { #ifdef CONFIG_DEBUG_PAGEALLOC @@ -1631,7 +1643,7 @@ static void slab_destroy_objs(struct kmem_cache *cachep, struct slab *slabp) if (cachep->dtor) { int i; for (i = 0; i < cachep->num; i++) { - void *objp = slabp->s_mem + cachep->buffer_size * i; + void *objp = index_to_obj(cachep, slabp, i); (cachep->dtor) (objp, cachep, 0); } } @@ -2307,7 +2319,7 @@ static void cache_init_objs(struct kmem_cache *cachep, int i; for (i = 0; i < cachep->num; i++) { - void *objp = slabp->s_mem + cachep->buffer_size * i; + void *objp = index_to_obj(cachep, slabp, i); #if DEBUG /* need to poison the objs? */ if (cachep->flags & SLAB_POISON) @@ -2363,7 +2375,7 @@ static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags) static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp, int nodeid) { - void *objp = slabp->s_mem + (slabp->free * cachep->buffer_size); + void *objp = index_to_obj(cachep, slabp, slabp->free); kmem_bufctl_t next; slabp->inuse++; @@ -2380,7 +2392,7 @@ static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp, int nod static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp, void *objp, int nodeid) { - unsigned int objnr = (unsigned)(objp-slabp->s_mem) / cachep->buffer_size; + unsigned int objnr = obj_to_index(cachep, slabp, objp); #if DEBUG /* Verify that the slab belongs to the intended node */ @@ -2565,10 +2577,10 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp, if (cachep->flags & SLAB_STORE_USER) *dbg_userword(cachep, objp) = caller; - objnr = (unsigned)(objp - slabp->s_mem) / cachep->buffer_size; + objnr = obj_to_index(cachep, slabp, objp); BUG_ON(objnr >= cachep->num); - BUG_ON(objp != slabp->s_mem + objnr * cachep->buffer_size); + BUG_ON(objp != index_to_obj(cachep, slabp, objnr)); if (cachep->flags & SLAB_DEBUG_INITIAL) { /* Need to call the slab's constructor so the