*
* Overloading of page flags that are otherwise used for LRU management.
*
- * PageActive The slab is used as a cpu cache. Allocations
- * may be performed from the slab. The slab is not
- * on any slab list and cannot be moved onto one.
- * The cpu slab may be equipped with an additioanl
+ * PageActive The slab is frozen and exempt from list processing.
+ * This means that the slab is dedicated to a purpose
+ * such as satisfying allocations for a specific
+ * processor. Objects may be freed in the slab while
+ * it is frozen but slab_free will then skip the usual
+ * list operations. It is up to the processor holding
+ * the slab to integrate the slab into the slab lists
+ * when the slab is no longer needed.
+ *
+ * One use of this flag is to mark slabs that are
+ * used for allocations. Then such a slab becomes a cpu
+ * slab. The cpu slab may be equipped with an additional
* lockless_freelist that allows lockless access to
* free objects in addition to the regular freelist
* that requires the slab lock.
* the fast path and disables lockless freelists.
*/
-static inline int SlabDebug(struct page *page)
-{
+#define FROZEN (1 << PG_active)
+
#ifdef CONFIG_SLUB_DEBUG
- return PageError(page);
+#define SLABDEBUG (1 << PG_error)
#else
- return 0;
+#define SLABDEBUG 0
#endif
+
+static inline int SlabFrozen(struct page *page)
+{
+ return page->flags & FROZEN;
+}
+
+static inline void SetSlabFrozen(struct page *page)
+{
+ page->flags |= FROZEN;
+}
+
+static inline void ClearSlabFrozen(struct page *page)
+{
+ page->flags &= ~FROZEN;
+}
+
+static inline int SlabDebug(struct page *page)
+{
+ return page->flags & SLABDEBUG;
}
static inline void SetSlabDebug(struct page *page)
{
-#ifdef CONFIG_SLUB_DEBUG
- SetPageError(page);
-#endif
+ page->flags |= SLABDEBUG;
}
static inline void ClearSlabDebug(struct page *page)
{
-#ifdef CONFIG_SLUB_DEBUG
- ClearPageError(page);
-#endif
+ page->flags &= ~SLABDEBUG;
}
/*
return search == NULL;
}
+static void trace(struct kmem_cache *s, struct page *page, void *object, int alloc)
+{
+ if (s->flags & SLAB_TRACE) {
+ printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
+ s->name,
+ alloc ? "alloc" : "free",
+ object, page->inuse,
+ page->freelist);
+
+ if (!alloc)
+ print_section("Object", (void *)object, s->objsize);
+
+ dump_stack();
+ }
+}
+
/*
* Tracking of fully allocated slabs for debugging purposes.
*/
spin_unlock(&n->list_lock);
}
-static int alloc_object_checks(struct kmem_cache *s, struct page *page,
- void *object)
+static void setup_object_debug(struct kmem_cache *s, struct page *page,
+ void *object)
+{
+ if (!(s->flags & (SLAB_STORE_USER|SLAB_RED_ZONE|__OBJECT_POISON)))
+ return;
+
+ init_object(s, object, 0);
+ init_tracking(s, object);
+}
+
+static int alloc_debug_processing(struct kmem_cache *s, struct page *page,
+ void *object, void *addr)
{
if (!check_slab(s, page))
goto bad;
goto bad;
}
- if (!object)
- return 1;
-
- if (!check_object(s, page, object, 0))
+ if (object && !check_object(s, page, object, 0))
goto bad;
+ /* Success perform special debug activities for allocs */
+ if (s->flags & SLAB_STORE_USER)
+ set_track(s, object, TRACK_ALLOC, addr);
+ trace(s, page, object, 1);
+ init_object(s, object, 1);
return 1;
+
bad:
if (PageSlab(page)) {
/*
return 0;
}
-static int free_object_checks(struct kmem_cache *s, struct page *page,
- void *object)
+static int free_debug_processing(struct kmem_cache *s, struct page *page,
+ void *object, void *addr)
{
if (!check_slab(s, page))
goto fail;
"to slab %s", object, page->slab->name);
goto fail;
}
+
+ /* Special debug activities for freeing objects */
+ if (!SlabFrozen(page) && !page->freelist)
+ remove_full(s, page);
+ if (s->flags & SLAB_STORE_USER)
+ set_track(s, object, TRACK_FREE, addr);
+ trace(s, page, object, 0);
+ init_object(s, object, 0);
return 1;
+
fail:
printk(KERN_ERR "@@@ SLUB: %s slab 0x%p object at 0x%p not freed.\n",
s->name, page, object);
return 0;
}
-static void trace(struct kmem_cache *s, struct page *page, void *object, int alloc)
-{
- if (s->flags & SLAB_TRACE) {
- printk(KERN_INFO "TRACE %s %s 0x%p inuse=%d fp=0x%p\n",
- s->name,
- alloc ? "alloc" : "free",
- object, page->inuse,
- page->freelist);
-
- if (!alloc)
- print_section("Object", (void *)object, s->objsize);
-
- dump_stack();
- }
-}
-
static int __init setup_slub_debug(char *str)
{
if (!str || *str != '=')
* Debugging or ctor may create a need to move the free
* pointer. Fail if this happens.
*/
- if (s->size >= 65535 * sizeof(void *)) {
+ if (s->objsize >= 65535 * sizeof(void *)) {
BUG_ON(s->flags & (SLAB_RED_ZONE | SLAB_POISON |
SLAB_STORE_USER | SLAB_DESTROY_BY_RCU));
BUG_ON(s->ctor);
s->flags |= slub_debug;
}
#else
+static inline void setup_object_debug(struct kmem_cache *s,
+ struct page *page, void *object) {}
-static inline int alloc_object_checks(struct kmem_cache *s,
- struct page *page, void *object) { return 0; }
+static inline int alloc_debug_processing(struct kmem_cache *s,
+ struct page *page, void *object, void *addr) { return 0; }
-static inline int free_object_checks(struct kmem_cache *s,
- struct page *page, void *object) { return 0; }
+static inline int free_debug_processing(struct kmem_cache *s,
+ struct page *page, void *object, void *addr) { return 0; }
-static inline void add_full(struct kmem_cache_node *n, struct page *page) {}
-static inline void remove_full(struct kmem_cache *s, struct page *page) {}
-static inline void trace(struct kmem_cache *s, struct page *page,
- void *object, int alloc) {}
-static inline void init_object(struct kmem_cache *s,
- void *object, int active) {}
-static inline void init_tracking(struct kmem_cache *s, void *object) {}
static inline int slab_pad_check(struct kmem_cache *s, struct page *page)
{ return 1; }
static inline int check_object(struct kmem_cache *s, struct page *page,
void *object, int active) { return 1; }
-static inline void set_track(struct kmem_cache *s, void *object,
- enum track_item alloc, void *addr) {}
+static inline void add_full(struct kmem_cache_node *n, struct page *page) {}
static inline void kmem_cache_open_debug_check(struct kmem_cache *s) {}
#define slub_debug 0
#endif
static void setup_object(struct kmem_cache *s, struct page *page,
void *object)
{
- if (SlabDebug(page)) {
- init_object(s, object, 0);
- init_tracking(s, object);
- }
-
+ setup_object_debug(s, page, object);
if (unlikely(s->ctor))
- s->ctor(object, s, SLAB_CTOR_CONSTRUCTOR);
+ s->ctor(object, s, 0);
}
static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node)
*
* Must hold list_lock.
*/
-static int lock_and_del_slab(struct kmem_cache_node *n, struct page *page)
+static inline int lock_and_freeze_slab(struct kmem_cache_node *n, struct page *page)
{
if (slab_trylock(page)) {
list_del(&page->lru);
n->nr_partial--;
+ SetSlabFrozen(page);
return 1;
}
return 0;
spin_lock(&n->list_lock);
list_for_each_entry(page, &n->partial, lru)
- if (lock_and_del_slab(n, page))
+ if (lock_and_freeze_slab(n, page))
goto out;
page = NULL;
out:
*
* On exit the slab lock will have been dropped.
*/
-static void putback_slab(struct kmem_cache *s, struct page *page)
+static void unfreeze_slab(struct kmem_cache *s, struct page *page)
{
struct kmem_cache_node *n = get_node(s, page_to_nid(page));
+ ClearSlabFrozen(page);
if (page->inuse) {
if (page->freelist)
page->inuse--;
}
s->cpu_slab[cpu] = NULL;
- ClearPageActive(page);
-
- putback_slab(s, page);
+ unfreeze_slab(s, page);
}
static void flush_slab(struct kmem_cache *s, struct page *page, int cpu)
new_slab:
page = get_partial(s, gfpflags, node);
if (page) {
-have_slab:
s->cpu_slab[cpu] = page;
- SetPageActive(page);
goto load_freelist;
}
flush_slab(s, s->cpu_slab[cpu], cpu);
}
slab_lock(page);
- goto have_slab;
+ SetSlabFrozen(page);
+ s->cpu_slab[cpu] = page;
+ goto load_freelist;
}
return NULL;
debug:
object = page->freelist;
- if (!alloc_object_checks(s, page, object))
+ if (!alloc_debug_processing(s, page, object, addr))
goto another_slab;
- if (s->flags & SLAB_STORE_USER)
- set_track(s, object, TRACK_ALLOC, addr);
- trace(s, page, object, 1);
- init_object(s, object, 1);
page->inuse++;
page->freelist = object[page->offset];
page->freelist = object;
page->inuse--;
- if (unlikely(PageActive(page)))
- /*
- * Cpu slabs are never on partial lists and are
- * never freed.
- */
+ if (unlikely(SlabFrozen(page)))
goto out_unlock;
if (unlikely(!page->inuse))
return;
debug:
- if (!free_object_checks(s, page, x))
+ if (!free_debug_processing(s, page, x, addr))
goto out_unlock;
- if (!PageActive(page) && !page->freelist)
- remove_full(s, page);
- if (s->flags & SLAB_STORE_USER)
- set_track(s, x, TRACK_FREE, addr);
- trace(s, page, object, 0);
- init_object(s, object, 0);
goto checks_ok;
}
page->freelist = get_freepointer(kmalloc_caches, n);
page->inuse++;
kmalloc_caches->node[node] = n;
- init_object(kmalloc_caches, n, 1);
+ setup_object_debug(kmalloc_caches, page, n);
init_kmem_cache_node(n);
atomic_long_inc(&n->nr_slabs);
add_partial(n, page);
*/
s->inuse = size;
-#ifdef CONFIG_SLUB_DEBUG
if (((flags & (SLAB_DESTROY_BY_RCU | SLAB_POISON)) ||
s->ctor)) {
/*
size += sizeof(void *);
}
+#ifdef CONFIG_SLUB_DEBUG
if (flags & SLAB_STORE_USER)
/*
* Need to store information about allocs and frees after
if (s)
return slab_alloc(s, flags, -1, __builtin_return_address(0));
- return NULL;
+ return ZERO_SIZE_PTR;
}
EXPORT_SYMBOL(__kmalloc);
if (s)
return slab_alloc(s, flags, node, __builtin_return_address(0));
- return NULL;
+ return ZERO_SIZE_PTR;
}
EXPORT_SYMBOL(__kmalloc_node);
#endif
size_t ksize(const void *object)
{
- struct page *page = get_object_page(object);
+ struct page *page;
struct kmem_cache *s;
+ if (object == ZERO_SIZE_PTR)
+ return 0;
+
+ page = get_object_page(object);
BUG_ON(!page);
s = page->slab;
BUG_ON(!s);
struct kmem_cache *s;
struct page *page;
- if (!x)
+ /*
+ * This has to be an unsigned comparison. According to Linus
+ * some gcc version treat a pointer as a signed entity. Then
+ * this comparison would be true for all "negative" pointers
+ * (which would cover the whole upper half of the address space).
+ */
+ if ((unsigned long)x <= (unsigned long)ZERO_SIZE_PTR)
return;
page = virt_to_head_page(x);
void *ret;
size_t ks;
- if (unlikely(!p))
+ if (unlikely(!p || p == ZERO_SIZE_PTR))
return kmalloc(new_size, flags);
if (unlikely(!new_size)) {
kfree(p);
- return NULL;
+ return ZERO_SIZE_PTR;
}
ks = ksize(p);
void __init kmem_cache_init(void)
{
int i;
+ int caches = 0;
#ifdef CONFIG_NUMA
/*
*/
create_kmalloc_cache(&kmalloc_caches[0], "kmem_cache_node",
sizeof(struct kmem_cache_node), GFP_KERNEL);
+ kmalloc_caches[0].refcount = -1;
+ caches++;
#endif
/* Able to allocate the per node structures */
slab_state = PARTIAL;
/* Caches that are not of the two-to-the-power-of size */
- create_kmalloc_cache(&kmalloc_caches[1],
+ if (KMALLOC_MIN_SIZE <= 64) {
+ create_kmalloc_cache(&kmalloc_caches[1],
"kmalloc-96", 96, GFP_KERNEL);
- create_kmalloc_cache(&kmalloc_caches[2],
+ caches++;
+ }
+ if (KMALLOC_MIN_SIZE <= 128) {
+ create_kmalloc_cache(&kmalloc_caches[2],
"kmalloc-192", 192, GFP_KERNEL);
+ caches++;
+ }
- for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++)
+ for (i = KMALLOC_SHIFT_LOW; i <= KMALLOC_SHIFT_HIGH; i++) {
create_kmalloc_cache(&kmalloc_caches[i],
"kmalloc", 1 << i, GFP_KERNEL);
+ caches++;
+ }
slab_state = UP;
nr_cpu_ids * sizeof(struct page *);
printk(KERN_INFO "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
- " Processors=%d, Nodes=%d\n",
- KMALLOC_SHIFT_HIGH, cache_line_size(),
+ " CPUs=%d, Nodes=%d\n",
+ caches, cache_line_size(),
slub_min_order, slub_max_order, slub_min_objects,
nr_cpu_ids, nr_node_ids);
}
if (s->ctor)
return 1;
+ /*
+ * We may have set a slab to be unmergeable during bootstrap.
+ */
+ if (s->refcount < 0)
+ return 1;
+
return 0;
}
up_read(&slub_lock);
}
+/*
+ * Version of __flush_cpu_slab for the case that interrupts
+ * are enabled.
+ */
+static void cpu_slab_flush(struct kmem_cache *s, int cpu)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __flush_cpu_slab(s, cpu);
+ local_irq_restore(flags);
+}
+
/*
* Use the cpu notifier to insure that the cpu slabs are flushed when
* necessary.
case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
case CPU_DEAD_FROZEN:
- for_all_slabs(__flush_cpu_slab, cpu);
+ for_all_slabs(cpu_slab_flush, cpu);
break;
default:
break;
struct kmem_cache *s = get_slab(size, gfpflags);
if (!s)
- return NULL;
+ return ZERO_SIZE_PTR;
return slab_alloc(s, gfpflags, -1, caller);
}
struct kmem_cache *s = get_slab(size, gfpflags);
if (!s)
- return NULL;
+ return ZERO_SIZE_PTR;
return slab_alloc(s, gfpflags, node, caller);
}
order = get_order(sizeof(struct location) * max);
- l = (void *)__get_free_pages(GFP_KERNEL, order);
+ l = (void *)__get_free_pages(GFP_ATOMIC, order);
if (!l)
return 0;
git.samba.org / sfrench / cifs-2.6.git / blobdiff