diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index bfee0bd1d435..34023c65d466 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -64,10 +64,7 @@ struct page {
#if NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS
spinlock_t ptl;
#endif
- struct {
- struct kmem_cache *slab; /* SLUB: Pointer to slab */
- void *end; /* SLUB: end marker */
- };
+ struct kmem_cache *slab; /* SLUB: Pointer to slab */
struct page *first_page; /* Compound tail pages */
};
union {
diff --git a/mm/slub.c b/mm/slub.c
index 74c65af0a54f..a873953e5a11 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -291,32 +291,15 @@ static inline struct kmem_cache_cpu *get_cpu_slab(struct kmem_cache *s, int cpu)
#endif
}
-/*
- * The end pointer in a slab is special. It points to the first object in the
- * slab but has bit 0 set to mark it.
- *
- * Note that SLUB relies on page_mapping returning NULL for pages with bit 0
- * in the mapping set.
- */
-static inline int is_end(void *addr)
-{
- return (unsigned long)addr & PAGE_MAPPING_ANON;
-}
-
-static void *slab_address(struct page *page)
-{
- return page->end - PAGE_MAPPING_ANON;
-}
-
static inline int check_valid_pointer(struct kmem_cache *s,
struct page *page, const void *object)
{
void *base;
- if (object == page->end)
+ if (!object)
return 1;
- base = slab_address(page);
+ base = page_address(page);
if (object < base || object >= base + s->objects * s->size ||
(object - base) % s->size) {
return 0;
@@ -349,8 +332,7 @@ static inline void set_freepointer(struct kmem_cache *s, void *object, void *fp)
/* Scan freelist */
#define for_each_free_object(__p, __s, __free) \
- for (__p = (__free); (__p) != page->end; __p = get_freepointer((__s),\
- __p))
+ 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)
@@ -502,7 +484,7 @@ static void slab_fix(struct kmem_cache *s, char *fmt, ...)
static void print_trailer(struct kmem_cache *s, struct page *page, u8 *p)
{
unsigned int off; /* Offset of last byte */
- u8 *addr = slab_address(page);
+ u8 *addr = page_address(page);
print_tracking(s, p);
@@ -680,7 +662,7 @@ static int slab_pad_check(struct kmem_cache *s, struct page *page)
if (!(s->flags & SLAB_POISON))
return 1;
- start = slab_address(page);
+ start = page_address(page);
end = start + (PAGE_SIZE << s->order);
length = s->objects * s->size;
remainder = end - (start + length);
@@ -748,7 +730,7 @@ static int check_object(struct kmem_cache *s, struct page *page,
* of the free objects in this slab. May cause
* another error because the object count is now wrong.
*/
- set_freepointer(s, p, page->end);
+ set_freepointer(s, p, NULL);
return 0;
}
return 1;
@@ -782,18 +764,18 @@ static int on_freelist(struct kmem_cache *s, struct page *page, void *search)
void *fp = page->freelist;
void *object = NULL;
- while (fp != page->end && nr <= s->objects) {
+ while (fp && nr <= s->objects) {
if (fp == search)
return 1;
if (!check_valid_pointer(s, page, fp)) {
if (object) {
object_err(s, page, object,
"Freechain corrupt");
- set_freepointer(s, object, page->end);
+ set_freepointer(s, object, NULL);
break;
} else {
slab_err(s, page, "Freepointer corrupt");
- page->freelist = page->end;
+ page->freelist = NULL;
page->inuse = s->objects;
slab_fix(s, "Freelist cleared");
return 0;
@@ -899,7 +881,7 @@ bad:
*/
slab_fix(s, "Marking all objects used");
page->inuse = s->objects;
- page->freelist = page->end;
+ page->freelist = NULL;
}
return 0;
}
@@ -939,7 +921,7 @@ static int free_debug_processing(struct kmem_cache *s, struct page *page,
}
/* Special debug activities for freeing objects */
- if (!SlabFrozen(page) && page->freelist == page->end)
+ if (!SlabFrozen(page) && !page->freelist)
remove_full(s, page);
if (s->flags & SLAB_STORE_USER)
set_track(s, object, TRACK_FREE, addr);
@@ -1124,7 +1106,6 @@ static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
SetSlabDebug(page);
start = page_address(page);
- page->end = start + 1;
if (unlikely(s->flags & SLAB_POISON))
memset(start, POISON_INUSE, PAGE_SIZE << s->order);
@@ -1136,7 +1117,7 @@ static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
last = p;
}
setup_object(s, page, last);
- set_freepointer(s, last, page->end);
+ set_freepointer(s, last, NULL);
page->freelist = start;
page->inuse = 0;
@@ -1152,7 +1133,7 @@ static void __free_slab(struct kmem_cache *s, struct page *page)
void *p;
slab_pad_check(s, page);
- for_each_object(p, s, slab_address(page))
+ for_each_object(p, s, page_address(page))
check_object(s, page, p, 0);
ClearSlabDebug(page);
}
@@ -1162,7 +1143,6 @@ static void __free_slab(struct kmem_cache *s, struct page *page)
NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
-pages);
- page->mapping = NULL;
__free_pages(page, s->order);
}
@@ -1366,7 +1346,7 @@ static void unfreeze_slab(struct kmem_cache *s, struct page *page, int tail)
ClearSlabFrozen(page);
if (page->inuse) {
- if (page->freelist != page->end) {
+ if (page->freelist) {
add_partial(n, page, tail);
stat(c, tail ? DEACTIVATE_TO_TAIL : DEACTIVATE_TO_HEAD);
} else {
@@ -1410,12 +1390,8 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c)
* Merge cpu freelist into freelist. Typically we get here
* because both freelists are empty. So this is unlikely
* to occur.
- *
- * We need to use _is_end here because deactivate slab may
- * be called for a debug slab. Then c->freelist may contain
- * a dummy pointer.
*/
- while (unlikely(!is_end(c->freelist))) {
+ while (unlikely(c->freelist)) {
void **object;
tail = 0; /* Hot objects. Put the slab first */
@@ -1517,7 +1493,7 @@ static void *__slab_alloc(struct kmem_cache *s,
stat(c, ALLOC_REFILL);
load_freelist:
object = c->page->freelist;
- if (unlikely(object == c->page->end))
+ if (unlikely(!object))
goto another_slab;
if (unlikely(SlabDebug(c->page)))
goto debug;
@@ -1525,7 +1501,7 @@ load_freelist:
object = c->page->freelist;
c->freelist = object[c->offset];
c->page->inuse = s->objects;
- c->page->freelist = c->page->end;
+ c->page->freelist = NULL;
c->node = page_to_nid(c->page);
unlock_out:
slab_unlock(c->page);
@@ -1607,7 +1583,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s,
local_irq_save(flags);
c = get_cpu_slab(s, smp_processor_id());
- if (unlikely(is_end(c->freelist) || !node_match(c, node)))
+ if (unlikely(!c->freelist || !node_match(c, node)))
object = __slab_alloc(s, gfpflags, node, addr, c);
@@ -1677,7 +1653,7 @@ checks_ok:
* was not on the partial list before
* then add it.
*/
- if (unlikely(prior == page->end)) {
+ if (unlikely(!prior)) {
add_partial(get_node(s, page_to_nid(page)), page, 1);
stat(c, FREE_ADD_PARTIAL);
}
@@ -1687,7 +1663,7 @@ out_unlock:
return;
slab_empty:
- if (prior != page->end) {
+ if (prior) {
/*
* Slab still on the partial list.
*/
@@ -1910,7 +1886,7 @@ static void init_kmem_cache_cpu(struct kmem_cache *s,
struct kmem_cache_cpu *c)
{
c->page = NULL;
- c->freelist = (void *)PAGE_MAPPING_ANON;
+ c->freelist = NULL;
c->node = 0;
c->offset = s->offset / sizeof(void *);
c->objsize = s->objsize;
@@ -3199,7 +3175,7 @@ static int validate_slab(struct kmem_cache *s, struct page *page,
unsigned long *map)
{
void *p;
- void *addr = slab_address(page);
+ void *addr = page_address(page);
if (!check_slab(s, page) ||
!on_freelist(s, page, NULL))
@@ -3482,7 +3458,7 @@ static int add_location(struct loc_track *t, struct kmem_cache *s,
static void process_slab(struct loc_track *t, struct kmem_cache *s,
struct page *page, enum track_item alloc)
{
- void *addr = slab_address(page);
+ void *addr = page_address(page);
DECLARE_BITMAP(map, s->objects);
void *p;