diff options
Diffstat (limited to 'mm/slub.c')
| -rw-r--r-- | mm/slub.c | 132 |
1 files changed, 81 insertions, 51 deletions
diff --git a/mm/slub.c b/mm/slub.c index e15aa7f193c9..e841d8921c22 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -281,11 +281,40 @@ static inline int slab_index(void *p, struct kmem_cache *s, void *addr) return (p - addr) / s->size; } +static inline size_t slab_ksize(const struct kmem_cache *s) +{ +#ifdef CONFIG_SLUB_DEBUG + /* + * Debugging requires use of the padding between object + * and whatever may come after it. + */ + if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) + return s->objsize; + +#endif + /* + * If we have the need to store the freelist pointer + * back there or track user information then we can + * only use the space before that information. + */ + if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER)) + return s->inuse; + /* + * Else we can use all the padding etc for the allocation + */ + return s->size; +} + +static inline int order_objects(int order, unsigned long size, int reserved) +{ + return ((PAGE_SIZE << order) - reserved) / size; +} + static inline struct kmem_cache_order_objects oo_make(int order, - unsigned long size) + unsigned long size, int reserved) { struct kmem_cache_order_objects x = { - (order << OO_SHIFT) + (PAGE_SIZE << order) / size + (order << OO_SHIFT) + order_objects(order, size, reserved) }; return x; @@ -617,7 +646,7 @@ static int slab_pad_check(struct kmem_cache *s, struct page *page) return 1; start = page_address(page); - length = (PAGE_SIZE << compound_order(page)); + length = (PAGE_SIZE << compound_order(page)) - s->reserved; end = start + length; remainder = length % s->size; if (!remainder) @@ -698,7 +727,7 @@ static int check_slab(struct kmem_cache *s, struct page *page) return 0; } - maxobj = (PAGE_SIZE << compound_order(page)) / s->size; + maxobj = order_objects(compound_order(page), s->size, s->reserved); if (page->objects > maxobj) { slab_err(s, page, "objects %u > max %u", s->name, page->objects, maxobj); @@ -748,7 +777,7 @@ static int on_freelist(struct kmem_cache *s, struct page *page, void *search) nr++; } - max_objects = (PAGE_SIZE << compound_order(page)) / s->size; + max_objects = order_objects(compound_order(page), s->size, s->reserved); if (max_objects > MAX_OBJS_PER_PAGE) max_objects = MAX_OBJS_PER_PAGE; @@ -800,7 +829,7 @@ static inline int slab_pre_alloc_hook(struct kmem_cache *s, gfp_t flags) static inline void slab_post_alloc_hook(struct kmem_cache *s, gfp_t flags, void *object) { flags &= gfp_allowed_mask; - kmemcheck_slab_alloc(s, flags, object, s->objsize); + kmemcheck_slab_alloc(s, flags, object, slab_ksize(s)); kmemleak_alloc_recursive(object, s->objsize, 1, s->flags, flags); } @@ -1249,21 +1278,38 @@ static void __free_slab(struct kmem_cache *s, struct page *page) __free_pages(page, order); } +#define need_reserve_slab_rcu \ + (sizeof(((struct page *)NULL)->lru) < sizeof(struct rcu_head)) + static void rcu_free_slab(struct rcu_head *h) { struct page *page; - page = container_of((struct list_head *)h, struct page, lru); + if (need_reserve_slab_rcu) + page = virt_to_head_page(h); + else + page = container_of((struct list_head *)h, struct page, lru); + __free_slab(page->slab, page); } static void free_slab(struct kmem_cache *s, struct page *page) { if (unlikely(s->flags & SLAB_DESTROY_BY_RCU)) { - /* - * RCU free overloads the RCU head over the LRU - */ - struct rcu_head *head = (void *)&page->lru; + struct rcu_head *head; + + if (need_reserve_slab_rcu) { + int order = compound_order(page); + int offset = (PAGE_SIZE << order) - s->reserved; + + VM_BUG_ON(s->reserved != sizeof(*head)); + head = page_address(page) + offset; + } else { + /* + * RCU free overloads the RCU head over the LRU + */ + head = (void *)&page->lru; + } call_rcu(head, rcu_free_slab); } else @@ -1988,13 +2034,13 @@ static int slub_nomerge; * the smallest order which will fit the object. */ static inline int slab_order(int size, int min_objects, - int max_order, int fract_leftover) + int max_order, int fract_leftover, int reserved) { int order; int rem; int min_order = slub_min_order; - if ((PAGE_SIZE << min_order) / size > MAX_OBJS_PER_PAGE) + if (order_objects(min_order, size, reserved) > MAX_OBJS_PER_PAGE) return get_order(size * MAX_OBJS_PER_PAGE) - 1; for (order = max(min_order, @@ -2003,10 +2049,10 @@ static inline int slab_order(int size, int min_objects, unsigned long slab_size = PAGE_SIZE << order; - if (slab_size < min_objects * size) + if (slab_size < min_objects * size + reserved) continue; - rem = slab_size % size; + rem = (slab_size - reserved) % size; if (rem <= slab_size / fract_leftover) break; @@ -2016,7 +2062,7 @@ static inline int slab_order(int size, int min_objects, return order; } -static inline int calculate_order(int size) +static inline int calculate_order(int size, int reserved) { int order; int min_objects; @@ -2034,14 +2080,14 @@ static inline int calculate_order(int size) min_objects = slub_min_objects; if (!min_objects) min_objects = 4 * (fls(nr_cpu_ids) + 1); - max_objects = (PAGE_SIZE << slub_max_order)/size; + max_objects = order_objects(slub_max_order, size, reserved); min_objects = min(min_objects, max_objects); while (min_objects > 1) { fraction = 16; while (fraction >= 4) { order = slab_order(size, min_objects, - slub_max_order, fraction); + slub_max_order, fraction, reserved); if (order <= slub_max_order) return order; fraction /= 2; @@ -2053,14 +2099,14 @@ static inline int calculate_order(int size) * We were unable to place multiple objects in a slab. Now * lets see if we can place a single object there. */ - order = slab_order(size, 1, slub_max_order, 1); + order = slab_order(size, 1, slub_max_order, 1, reserved); if (order <= slub_max_order) return order; /* * Doh this slab cannot be placed using slub_max_order. */ - order = slab_order(size, 1, MAX_ORDER, 1); + order = slab_order(size, 1, MAX_ORDER, 1, reserved); if (order < MAX_ORDER) return order; return -ENOSYS; @@ -2311,7 +2357,7 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order) if (forced_order >= 0) order = forced_order; else - order = calculate_order(size); + order = calculate_order(size, s->reserved); if (order < 0) return 0; @@ -2329,8 +2375,8 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order) /* * Determine the number of objects per slab */ - s->oo = oo_make(order, size); - s->min = oo_make(get_order(size), size); + s->oo = oo_make(order, size, s->reserved); + s->min = oo_make(get_order(size), size, s->reserved); if (oo_objects(s->oo) > oo_objects(s->max)) s->max = s->oo; @@ -2349,6 +2395,10 @@ static int kmem_cache_open(struct kmem_cache *s, s->objsize = size; s->align = align; s->flags = kmem_cache_flags(size, flags, name, ctor); + s->reserved = 0; + + if (need_reserve_slab_rcu && (s->flags & SLAB_DESTROY_BY_RCU)) + s->reserved = sizeof(struct rcu_head); if (!calculate_sizes(s, -1)) goto error; @@ -2399,12 +2449,6 @@ unsigned int kmem_cache_size(struct kmem_cache *s) } EXPORT_SYMBOL(kmem_cache_size); -const char *kmem_cache_name(struct kmem_cache *s) -{ - return s->name; -} -EXPORT_SYMBOL(kmem_cache_name); - static void list_slab_objects(struct kmem_cache *s, struct page *page, const char *text) { @@ -2696,7 +2740,6 @@ EXPORT_SYMBOL(__kmalloc_node); size_t ksize(const void *object) { struct page *page; - struct kmem_cache *s; if (unlikely(object == ZERO_SIZE_PTR)) return 0; @@ -2707,28 +2750,8 @@ size_t ksize(const void *object) WARN_ON(!PageCompound(page)); return PAGE_SIZE << compound_order(page); } - s = page->slab; - -#ifdef CONFIG_SLUB_DEBUG - /* - * Debugging requires use of the padding between object - * and whatever may come after it. - */ - if (s->flags & (SLAB_RED_ZONE | SLAB_POISON)) - return s->objsize; -#endif - /* - * If we have the need to store the freelist pointer - * back there or track user information then we can - * only use the space before that information. - */ - if (s->flags & (SLAB_DESTROY_BY_RCU | SLAB_STORE_USER)) - return s->inuse; - /* - * Else we can use all the padding etc for the allocation - */ - return s->size; + return slab_ksize(page->slab); } EXPORT_SYMBOL(ksize); @@ -4017,6 +4040,12 @@ static ssize_t destroy_by_rcu_show(struct kmem_cache *s, char *buf) } SLAB_ATTR_RO(destroy_by_rcu); +static ssize_t reserved_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", s->reserved); +} +SLAB_ATTR_RO(reserved); + #ifdef CONFIG_SLUB_DEBUG static ssize_t slabs_show(struct kmem_cache *s, char *buf) { @@ -4303,6 +4332,7 @@ static struct attribute *slab_attrs[] = { &reclaim_account_attr.attr, &destroy_by_rcu_attr.attr, &shrink_attr.attr, + &reserved_attr.attr, #ifdef CONFIG_SLUB_DEBUG &total_objects_attr.attr, &slabs_attr.attr, |