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>
diff --git a/mm/slub.c b/mm/slub.c
index 15189d8..e97627b 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -209,6 +209,38 @@
}
/*
+ * 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
*/
static void print_section(char *text, u8 *addr, unsigned int length)
@@ -244,23 +276,6 @@
}
/*
- * 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.
*/
struct track {
@@ -852,7 +867,7 @@
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 @@
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 @@
{
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 @@
/* 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 @@
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);