/* 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
return (unsigned long)addr & PAGE_MAPPING_ANON;
}
-void *slab_address(struct page *page)
+static void *slab_address(struct page *page)
{
return page->end - PAGE_MAPPING_ANON;
}
endobject, red, s->inuse - s->objsize))
return 0;
} else {
- if ((s->flags & SLAB_POISON) && s->objsize < s->inuse)
- check_bytes_and_report(s, page, p, "Alignment padding", endobject,
- POISON_INUSE, s->inuse - s->objsize);
+ if ((s->flags & SLAB_POISON) && s->objsize < s->inuse) {
+ check_bytes_and_report(s, page, p, "Alignment padding",
+ endobject, POISON_INUSE, s->inuse - s->objsize);
+ }
}
if (s->flags & SLAB_POISON) {
return 0;
if (unlikely(s != page->slab)) {
- if (!PageSlab(page))
+ if (!PageSlab(page)) {
slab_err(s, page, "Attempt to free object(0x%p) "
"outside of slab", object);
- else
- if (!page->slab) {
+ } else if (!page->slab) {
printk(KERN_ERR
"SLUB <none>: no slab for object 0x%p.\n",
object);
*/
if (slub_debug && (!slub_debug_slabs ||
strncmp(slub_debug_slabs, name,
- strlen(slub_debug_slabs)) == 0))
+ strlen(slub_debug_slabs)) == 0))
flags |= slub_debug;
}
struct page *page;
int pages = 1 << s->order;
- if (s->order)
- flags |= __GFP_COMP;
-
- if (s->flags & SLAB_CACHE_DMA)
- flags |= SLUB_DMA;
-
- if (s->flags & SLAB_RECLAIM_ACCOUNT)
- flags |= __GFP_RECLAIMABLE;
+ flags |= s->allocflags;
if (node == -1)
page = alloc_pages(flags, s->order);
static __always_inline void slab_unlock(struct page *page)
{
- bit_spin_unlock(PG_locked, &page->flags);
+ __bit_spin_unlock(PG_locked, &page->flags);
}
static __always_inline int slab_trylock(struct page *page)
get_cycles() % 1024 > s->remote_node_defrag_ratio)
return NULL;
- zonelist = &NODE_DATA(slab_node(current->mempolicy))
- ->node_zonelists[gfp_zone(flags)];
+ zonelist = &NODE_DATA(
+ slab_node(current->mempolicy))->node_zonelists[gfp_zone(flags)];
for (z = zonelist->zones; *z; z++) {
struct kmem_cache_node *n;
unlock_out:
slab_unlock(c->page);
stat(c, ALLOC_SLOWPATH);
-out:
#ifdef SLUB_FASTPATH
local_irq_restore(flags);
#endif
c->page = new;
goto load_freelist;
}
- object = NULL;
- goto out;
+#ifdef SLUB_FASTPATH
+ local_irq_restore(flags);
+#endif
+ /*
+ * 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))
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;
+ s->allocflags = 0;
+ if (s->order)
+ s->allocflags |= __GFP_COMP;
+
+ if (s->flags & SLAB_CACHE_DMA)
+ s->allocflags |= SLUB_DMA;
+
+ if (s->flags & SLAB_RECLAIM_ACCOUNT)
+ s->allocflags |= __GFP_RECLAIMABLE;
+
/*
* Determine the number of objects per slab
*/
* 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);
goto unlock_out;
realsize = kmalloc_caches[index].objsize;
- text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d", (unsigned int)realsize),
+ text = kasprintf(flags & ~SLUB_DMA, "kmalloc_dma-%d",
+ (unsigned int)realsize);
s = kmalloc(kmem_size, flags & ~SLUB_DMA);
if (!s || !text || !kmem_cache_open(s, flags, text,
{
struct kmem_cache *s;
- if (unlikely(size > PAGE_SIZE / 2))
- return (void *)__get_free_pages(flags | __GFP_COMP,
- get_order(size));
+ 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))
- return (void *)__get_free_pages(flags | __GFP_COMP,
- get_order(size));
+ 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);
#endif
- printk(KERN_INFO "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
+ printk(KERN_INFO
+ "SLUB: Genslabs=%d, HWalign=%d, Order=%d-%d, MinObjects=%d,"
" CPUs=%d, Nodes=%d\n",
caches, cache_line_size(),
slub_min_order, slub_max_order, slub_min_objects,
if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
return 1;
+ if ((s->flags & __PAGE_ALLOC_FALLBACK))
+ return 1;
+
if (s->ctor)
return 1;
}
static struct notifier_block __cpuinitdata slab_notifier = {
- &slab_cpuup_callback, NULL, 0
+ .notifier_call = slab_cpuup_callback
};
#endif
{
struct kmem_cache *s;
- if (unlikely(size > PAGE_SIZE / 2))
- return (void *)__get_free_pages(gfpflags | __GFP_COMP,
- get_order(size));
+ if (unlikely(size > PAGE_SIZE))
+ return kmalloc_large(size, gfpflags);
+
s = get_slab(size, gfpflags);
if (unlikely(ZERO_OR_NULL_PTR(s)))
{
struct kmem_cache *s;
- if (unlikely(size > PAGE_SIZE / 2))
- return (void *)__get_free_pages(gfpflags | __GFP_COMP,
- get_order(size));
+ if (unlikely(size > PAGE_SIZE))
+ return kmalloc_large(size, gfpflags);
+
s = get_slab(size, gfpflags);
if (unlikely(ZERO_OR_NULL_PTR(s)))
p = kzalloc(32, GFP_KERNEL);
p[32 + sizeof(void *)] = 0x34;
printk(KERN_ERR "\n2. kmalloc-32: Clobber next pointer/next slab"
- " 0x34 -> -0x%p\n", p);
- printk(KERN_ERR "If allocated object is overwritten then not detectable\n\n");
+ " 0x34 -> -0x%p\n", p);
+ printk(KERN_ERR
+ "If allocated object is overwritten then not detectable\n\n");
validate_slab_cache(kmalloc_caches + 5);
p = kzalloc(64, GFP_KERNEL);
*p = 0x56;
printk(KERN_ERR "\n3. kmalloc-64: corrupting random byte 0x56->0x%p\n",
p);
- printk(KERN_ERR "If allocated object is overwritten then not detectable\n\n");
+ printk(KERN_ERR
+ "If allocated object is overwritten then not detectable\n\n");
validate_slab_cache(kmalloc_caches + 6);
printk(KERN_ERR "\nB. Corruption after free\n");
p = kzalloc(256, GFP_KERNEL);
kfree(p);
p[50] = 0x9a;
- printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n", p);
+ printk(KERN_ERR "\n2. kmalloc-256: Clobber 50th byte 0x9a->0x%p\n\n",
+ p);
validate_slab_cache(kmalloc_caches + 8);
p = kzalloc(512, GFP_KERNEL);