From 5f80b13ae45df7da6646d1881da186318e70b6b6 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Fri, 15 Apr 2011 14:48:13 -0500 Subject: [PATCH] slub: get_map() function to establish map of free objects in a slab The bit map of free objects in a slab page is determined in various functions if debugging is enabled. Provide a common function for that purpose. Signed-off-by: Christoph Lameter Signed-off-by: Pekka Enberg --- mm/slub.c | 34 ++++++++++++++++++++++------------ 1 file changed, 22 insertions(+), 12 deletions(-) diff --git a/mm/slub.c b/mm/slub.c index 5284fb779670..837f932671a1 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -271,10 +271,6 @@ static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp) for (__p = (__addr); __p < (__addr) + (__objects) * (__s)->size;\ __p += (__s)->size) -/* Scan freelist */ -#define for_each_free_object(__p, __s, __free) \ - for (__p = (__free); __p; __p = get_freepointer((__s), __p)) - /* Determine object index from a given position */ static inline int slab_index(void *p, struct kmem_cache *s, void *addr) { @@ -330,6 +326,21 @@ static inline int oo_objects(struct kmem_cache_order_objects x) return x.x & OO_MASK; } +/* + * Determine a map of object in use on a page. + * + * Slab lock or node listlock must be held to guarantee that the page does + * not vanish from under us. + */ +static void get_map(struct kmem_cache *s, struct page *page, unsigned long *map) +{ + void *p; + void *addr = page_address(page); + + for (p = page->freelist; p; p = get_freepointer(s, p)) + set_bit(slab_index(p, s, addr), map); +} + #ifdef CONFIG_SLUB_DEBUG /* * Debug settings: @@ -2673,9 +2684,8 @@ static void list_slab_objects(struct kmem_cache *s, struct page *page, return; slab_err(s, page, "%s", text); slab_lock(page); - for_each_free_object(p, s, page->freelist) - set_bit(slab_index(p, s, addr), map); + get_map(s, page, map); for_each_object(p, s, addr, page->objects) { if (!test_bit(slab_index(p, s, addr), map)) { @@ -3610,10 +3620,11 @@ static int validate_slab(struct kmem_cache *s, struct page *page, /* Now we know that a valid freelist exists */ bitmap_zero(map, page->objects); - for_each_free_object(p, s, page->freelist) { - set_bit(slab_index(p, s, addr), map); - if (!check_object(s, page, p, SLUB_RED_INACTIVE)) - return 0; + get_map(s, page, map); + for_each_object(p, s, addr, page->objects) { + if (test_bit(slab_index(p, s, addr), map)) + if (!check_object(s, page, p, SLUB_RED_INACTIVE)) + return 0; } for_each_object(p, s, addr, page->objects) @@ -3821,8 +3832,7 @@ static void process_slab(struct loc_track *t, struct kmem_cache *s, void *p; bitmap_zero(map, page->objects); - for_each_free_object(p, s, page->freelist) - set_bit(slab_index(p, s, addr), map); + get_map(s, page, map); for_each_object(p, s, addr, page->objects) if (!test_bit(slab_index(p, s, addr), map))