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: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Christoph Lameter 2007-05-09 02:32:40 -07:00 committed by Linus Torvalds
parent 672bba3a4b
commit 7656c72b5a

View File

@ -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);