diff options
| -rw-r--r-- | include/linux/slub_def.h | 16 | ||||
| -rw-r--r-- | mm/slub.c | 15 |
2 files changed, 21 insertions, 10 deletions
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h index d2153789bd9f..30e91c83d401 100644 --- a/include/linux/slub_def.h +++ b/include/linux/slub_def.h @@ -8,6 +8,7 @@ * (C) 2007 SGI, Christoph Lameter */ #include <linux/kobject.h> +#include <linux/reciprocal_div.h> enum stat_item { ALLOC_FASTPATH, /* Allocation from cpu slab */ @@ -86,6 +87,7 @@ struct kmem_cache { unsigned long min_partial; unsigned int size; /* The size of an object including metadata */ unsigned int object_size;/* The size of an object without metadata */ + struct reciprocal_value reciprocal_size; unsigned int offset; /* Free pointer offset */ #ifdef CONFIG_SLUB_CPU_PARTIAL /* Number of per cpu partial objects to keep around */ @@ -182,4 +184,18 @@ static inline void *nearest_obj(struct kmem_cache *cache, struct page *page, return result; } +/* Determine object index from a given position */ +static inline unsigned int __obj_to_index(const struct kmem_cache *cache, + void *addr, void *obj) +{ + return reciprocal_divide(kasan_reset_tag(obj) - addr, + cache->reciprocal_size); +} + +static inline unsigned int obj_to_index(const struct kmem_cache *cache, + const struct page *page, void *obj) +{ + return __obj_to_index(cache, page_address(page), obj); +} + #endif /* _LINUX_SLUB_DEF_H */ diff --git a/mm/slub.c b/mm/slub.c index 2d73d677f7ac..2a3075538f26 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -317,12 +317,6 @@ static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp) __p < (__addr) + (__objects) * (__s)->size; \ __p += (__s)->size) -/* Determine object index from a given position */ -static inline unsigned int slab_index(void *p, struct kmem_cache *s, void *addr) -{ - return (kasan_reset_tag(p) - addr) / s->size; -} - static inline unsigned int order_objects(unsigned int order, unsigned int size) { return ((unsigned int)PAGE_SIZE << order) / size; @@ -465,7 +459,7 @@ static unsigned long *get_map(struct kmem_cache *s, struct page *page) bitmap_zero(object_map, page->objects); for (p = page->freelist; p; p = get_freepointer(s, p)) - set_bit(slab_index(p, s, addr), object_map); + set_bit(__obj_to_index(s, addr, p), object_map); return object_map; } @@ -3754,6 +3748,7 @@ static int calculate_sizes(struct kmem_cache *s, int forced_order) */ size = ALIGN(size, s->align); s->size = size; + s->reciprocal_size = reciprocal_value(size); if (forced_order >= 0) order = forced_order; else @@ -3858,7 +3853,7 @@ static void list_slab_objects(struct kmem_cache *s, struct page *page, map = get_map(s, page); for_each_object(p, s, addr, page->objects) { - if (!test_bit(slab_index(p, s, addr), map)) { + if (!test_bit(__obj_to_index(s, addr, p), map)) { pr_err("INFO: Object 0x%p @offset=%tu\n", p, p - addr); print_tracking(s, p); } @@ -4574,7 +4569,7 @@ static void validate_slab(struct kmem_cache *s, struct page *page) /* Now we know that a valid freelist exists */ map = get_map(s, page); for_each_object(p, s, addr, page->objects) { - u8 val = test_bit(slab_index(p, s, addr), map) ? + u8 val = test_bit(__obj_to_index(s, addr, p), map) ? SLUB_RED_INACTIVE : SLUB_RED_ACTIVE; if (!check_object(s, page, p, val)) @@ -4765,7 +4760,7 @@ static void process_slab(struct loc_track *t, struct kmem_cache *s, map = get_map(s, page); for_each_object(p, s, addr, page->objects) - if (!test_bit(slab_index(p, s, addr), map)) + if (!test_bit(__obj_to_index(s, addr, p), map)) add_location(t, s, get_track(s, p, alloc)); put_map(map); } |