/* Enable to test recovery from slab corruption on boot */
#undef SLUB_RESILIENCY_TEST
-/*
- * Currently fastpath is not supported if preemption is enabled.
- */
-#if defined(CONFIG_FAST_CMPXCHG_LOCAL) && !defined(CONFIG_PREEMPT)
-#define SLUB_FASTPATH
-#endif
-
#if PAGE_SHIFT <= 12
/*
/* Internal SLUB flags */
#define __OBJECT_POISON 0x80000000 /* Poison object */
#define __SYSFS_ADD_DEFERRED 0x40000000 /* Not yet visible via sysfs */
+#define __KMALLOC_CACHE 0x20000000 /* objects freed using kfree */
+#define __PAGE_ALLOC_FALLBACK 0x10000000 /* Allow fallback to page alloc */
/* Not all arches define cache_line_size */
#ifndef cache_line_size
#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;
/* 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)
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);
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);
* 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;
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;
*/
slab_fix(s, "Marking all objects used");
page->inuse = s->objects;
- page->freelist = page->end;
+ page->freelist = NULL;
}
return 0;
}
}
/* 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);
SetSlabDebug(page);
start = page_address(page);
- page->end = start + 1;
if (unlikely(s->flags & SLAB_POISON))
memset(start, POISON_INUSE, PAGE_SIZE << s->order);
last = p;
}
setup_object(s, page, last);
- set_freepointer(s, last, page->end);
+ set_freepointer(s, last, NULL);
page->freelist = start;
page->inuse = 0;
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);
}
NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
-pages);
- page->mapping = NULL;
__free_pages(page, s->order);
}
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 {
* 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 */
{
void **object;
struct page *new;
-#ifdef SLUB_FASTPATH
- unsigned long flags;
- local_irq_save(flags);
-#endif
if (!c->page)
goto new_slab;
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;
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);
stat(c, ALLOC_SLOWPATH);
-out:
-#ifdef SLUB_FASTPATH
- local_irq_restore(flags);
-#endif
return object;
another_slab:
c->page = new;
goto load_freelist;
}
- object = NULL;
- goto out;
+
+ /*
+ * No memory available.
+ *
+ * If the slab uses higher order allocs but the object is
+ * smaller than a page size then we can fallback in emergencies
+ * to the page allocator via kmalloc_large. The page allocator may
+ * have failed to obtain a higher order page and we can try to
+ * allocate a single page if the object fits into a single page.
+ * That is only possible if certain conditions are met that are being
+ * checked when a slab is created.
+ */
+ if (!(gfpflags & __GFP_NORETRY) && (s->flags & __PAGE_ALLOC_FALLBACK))
+ return kmalloc_large(s->objsize, gfpflags);
+
+ return NULL;
debug:
object = c->page->freelist;
if (!alloc_debug_processing(s, c->page, object, addr))
{
void **object;
struct kmem_cache_cpu *c;
-
-/*
- * The SLUB_FASTPATH path is provisional and is currently disabled if the
- * kernel is compiled with preemption or if the arch does not support
- * fast cmpxchg operations. There are a couple of coming changes that will
- * simplify matters and allow preemption. Ultimately we may end up making
- * SLUB_FASTPATH the default.
- *
- * 1. The introduction of the per cpu allocator will avoid array lookups
- * through get_cpu_slab(). A special register can be used instead.
- *
- * 2. The introduction of per cpu atomic operations (cpu_ops) means that
- * we can realize the logic here entirely with per cpu atomics. The
- * per cpu atomic ops will take care of the preemption issues.
- */
-
-#ifdef SLUB_FASTPATH
- c = get_cpu_slab(s, raw_smp_processor_id());
- do {
- object = c->freelist;
- if (unlikely(is_end(object) || !node_match(c, node))) {
- object = __slab_alloc(s, gfpflags, node, addr, c);
- break;
- }
- stat(c, ALLOC_FASTPATH);
- } while (cmpxchg_local(&c->freelist, object, object[c->offset])
- != object);
-#else
unsigned long flags;
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);
stat(c, ALLOC_FASTPATH);
}
local_irq_restore(flags);
-#endif
if (unlikely((gfpflags & __GFP_ZERO) && object))
memset(object, 0, c->objsize);
void **object = (void *)x;
struct kmem_cache_cpu *c;
-#ifdef SLUB_FASTPATH
- unsigned long flags;
-
- local_irq_save(flags);
-#endif
c = get_cpu_slab(s, raw_smp_processor_id());
stat(c, FREE_SLOWPATH);
slab_lock(page);
* 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);
}
out_unlock:
slab_unlock(page);
-#ifdef SLUB_FASTPATH
- local_irq_restore(flags);
-#endif
return;
slab_empty:
- if (prior != page->end) {
+ if (prior) {
/*
* Slab still on the partial list.
*/
}
slab_unlock(page);
stat(c, FREE_SLAB);
-#ifdef SLUB_FASTPATH
- local_irq_restore(flags);
-#endif
discard_slab(s, page);
return;
{
void **object = (void *)x;
struct kmem_cache_cpu *c;
-
-#ifdef SLUB_FASTPATH
- void **freelist;
-
- c = get_cpu_slab(s, raw_smp_processor_id());
- debug_check_no_locks_freed(object, s->objsize);
- do {
- freelist = c->freelist;
- barrier();
- /*
- * If the compiler would reorder the retrieval of c->page to
- * come before c->freelist then an interrupt could
- * change the cpu slab before we retrieve c->freelist. We
- * could be matching on a page no longer active and put the
- * object onto the freelist of the wrong slab.
- *
- * On the other hand: If we already have the freelist pointer
- * then any change of cpu_slab will cause the cmpxchg to fail
- * since the freelist pointers are unique per slab.
- */
- if (unlikely(page != c->page || c->node < 0)) {
- __slab_free(s, page, x, addr, c->offset);
- break;
- }
- object[c->offset] = freelist;
- stat(c, FREE_FASTPATH);
- } while (cmpxchg_local(&c->freelist, freelist, object) != freelist);
-#else
unsigned long flags;
local_irq_save(flags);
__slab_free(s, page, x, addr, c->offset);
local_irq_restore(flags);
-#endif
}
void kmem_cache_free(struct kmem_cache *s, void *x)
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;
size = ALIGN(size, align);
s->size = size;
- s->order = calculate_order(size);
+ if ((flags & __KMALLOC_CACHE) &&
+ PAGE_SIZE / size < slub_min_objects) {
+ /*
+ * Kmalloc cache that would not have enough objects in
+ * an order 0 page. Kmalloc slabs can fallback to
+ * page allocator order 0 allocs so take a reasonably large
+ * order that will allows us a good number of objects.
+ */
+ s->order = max(slub_max_order, PAGE_ALLOC_COSTLY_ORDER);
+ s->flags |= __PAGE_ALLOC_FALLBACK;
+ s->allocflags |= __GFP_NOWARN;
+ } else
+ s->order = calculate_order(size);
+
if (s->order < 0)
return 0;
* Kmalloc subsystem
*******************************************************************/
-struct kmem_cache kmalloc_caches[PAGE_SHIFT] __cacheline_aligned;
+struct kmem_cache kmalloc_caches[PAGE_SHIFT + 1] __cacheline_aligned;
EXPORT_SYMBOL(kmalloc_caches);
#ifdef CONFIG_ZONE_DMA
-static struct kmem_cache *kmalloc_caches_dma[PAGE_SHIFT];
+static struct kmem_cache *kmalloc_caches_dma[PAGE_SHIFT + 1];
#endif
static int __init setup_slub_min_order(char *str)
down_write(&slub_lock);
if (!kmem_cache_open(s, gfp_flags, name, size, ARCH_KMALLOC_MINALIGN,
- flags, NULL))
+ flags | __KMALLOC_CACHE, NULL))
goto panic;
list_add(&s->list, &slab_caches);
{
struct kmem_cache *s;
- if (unlikely(size > PAGE_SIZE / 2))
+ if (unlikely(size > PAGE_SIZE))
return kmalloc_large(size, flags);
s = get_slab(size, flags);
{
struct kmem_cache *s;
- if (unlikely(size > PAGE_SIZE / 2))
+ if (unlikely(size > PAGE_SIZE))
return kmalloc_large(size, flags);
s = get_slab(size, flags);
caches++;
}
- for (i = KMALLOC_SHIFT_LOW; i < PAGE_SHIFT; i++) {
+ for (i = KMALLOC_SHIFT_LOW; i <= PAGE_SHIFT; i++) {
create_kmalloc_cache(&kmalloc_caches[i],
"kmalloc", 1 << i, GFP_KERNEL);
caches++;
slab_state = UP;
/* Provide the correct kmalloc names now that the caches are up */
- for (i = KMALLOC_SHIFT_LOW; i < PAGE_SHIFT; i++)
+ for (i = KMALLOC_SHIFT_LOW; i <= PAGE_SHIFT; i++)
kmalloc_caches[i]. name =
kasprintf(GFP_KERNEL, "kmalloc-%d", 1 << i);
if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
return 1;
+ if ((s->flags & __PAGE_ALLOC_FALLBACK))
+ return 1;
+
if (s->ctor)
return 1;
{
struct kmem_cache *s;
- if (unlikely(size > PAGE_SIZE / 2))
+ if (unlikely(size > PAGE_SIZE))
return kmalloc_large(size, gfpflags);
s = get_slab(size, gfpflags);
{
struct kmem_cache *s;
- if (unlikely(size > PAGE_SIZE / 2))
+ if (unlikely(size > PAGE_SIZE))
return kmalloc_large(size, gfpflags);
s = get_slab(size, gfpflags);
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))
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;
projects / linux-2.6-omap-h63xx.git / blobdiff