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Commit 7656c72b authored by Christoph Lameter's avatar Christoph Lameter Committed by Linus Torvalds
Browse files

SLUB: add macros for scanning objects in a slab 



Scanning of objects happens in a number of functions.  Consolidate that code.
DECLARE_BITMAP instead of coding the declaration for bitmaps.

Signed-off-by: default avatarChristoph Lameter <clameter@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 672bba3a

mm/slub.c

+44 −31
Original line number Diff line number Diff line
@@ -208,6 +208,38 @@ static inline struct kmem_cache_node *get_node(struct kmem_cache *s, int node) 
#endif

}



/*

 * Slow version of get and set free pointer.

 *

 * This version requires touching the cache lines of kmem_cache which

 * we avoid to do in the fast alloc free paths. There we obtain the offset

 * from the page struct.

 */

static inline void *get_freepointer(struct kmem_cache *s, void *object)

{

	return *(void **)(object + s->offset);

}



static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)

{

	*(void **)(object + s->offset) = fp;

}



/* Loop over all objects in a slab */

#define for_each_object(__p, __s, __addr) \

	for (__p = (__addr); __p < (__addr) + (__s)->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)

{

	return (p - addr) / s->size;

}



/*

 * Object debugging

 */
@@ -243,23 +275,6 @@ static void print_section(char *text, u8 *addr, unsigned int length) 
	}

}



/*

 * Slow version of get and set free pointer.

 *

 * This version requires touching the cache lines of kmem_cache which

 * we avoid to do in the fast alloc free paths. There we obtain the offset

 * from the page struct.

 */

static void *get_freepointer(struct kmem_cache *s, void *object)

{

	return *(void **)(object + s->offset);

}



static void set_freepointer(struct kmem_cache *s, void *object, void *fp)

{

	*(void **)(object + s->offset) = fp;

}



/*

 * Tracking user of a slab.

 */
@@ -852,7 +867,7 @@ static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node) 
		memset(start, POISON_INUSE, PAGE_SIZE << s->order);



	last = start;

	for (p = start + s->size; p < end; p += s->size) {

	for_each_object(p, s, start) {

		setup_object(s, page, last);

		set_freepointer(s, last, p);

		last = p;
@@ -873,12 +888,10 @@ static void __free_slab(struct kmem_cache *s, struct page *page) 
	int pages = 1 << s->order;



	if (unlikely(PageError(page) || s->dtor)) {

		void *start = page_address(page);

		void *end = start + (pages << PAGE_SHIFT);

		void *p;



		slab_pad_check(s, page);

		for (p = start; p <= end - s->size; p += s->size) {

		for_each_object(p, s, page_address(page)) {

			if (s->dtor)

				s->dtor(p, s, 0);

			check_object(s, page, p, 0);
@@ -2583,7 +2596,7 @@ static int validate_slab(struct kmem_cache *s, struct page *page) 
{

	void *p;

	void *addr = page_address(page);

	unsigned long map[BITS_TO_LONGS(s->objects)];

	DECLARE_BITMAP(map, s->objects);



	if (!check_slab(s, page) ||

			!on_freelist(s, page, NULL))
@@ -2592,14 +2605,14 @@ static int validate_slab(struct kmem_cache *s, struct page *page) 
	/* Now we know that a valid freelist exists */

	bitmap_zero(map, s->objects);



	for(p = page->freelist; p; p = get_freepointer(s, p)) {

		set_bit((p - addr) / s->size, map);

	for_each_free_object(p, s, page->freelist) {

		set_bit(slab_index(p, s, addr), map);

		if (!check_object(s, page, p, 0))

			return 0;

	}



	for(p = addr; p < addr + s->objects * s->size; p += s->size)

		if (!test_bit((p - addr) / s->size, map))

	for_each_object(p, s, addr)

		if (!test_bit(slab_index(p, s, addr), map))

			if (!check_object(s, page, p, 1))

				return 0;

	return 1;
@@ -2771,15 +2784,15 @@ static void process_slab(struct loc_track *t, struct kmem_cache *s, 
		struct page *page, enum track_item alloc)

{

	void *addr = page_address(page);

	unsigned long map[BITS_TO_LONGS(s->objects)];

	DECLARE_BITMAP(map, s->objects);

	void *p;



	bitmap_zero(map, s->objects);

	for (p = page->freelist; p; p = get_freepointer(s, p))

		set_bit((p - addr) / s->size, map);

	for_each_free_object(p, s, page->freelist)

		set_bit(slab_index(p, s, addr), map);



	for (p = addr; p < addr + s->objects * s->size; p += s->size)

		if (!test_bit((p - addr) / s->size, map)) {

	for_each_object(p, s, addr)

		if (!test_bit(slab_index(p, s, addr), map)) {

			void *addr = get_track(s, p, alloc)->addr;



			add_location(t, s, addr);