[linux-2.6-block.git] / mm / slob.c

/*
 * SLOB Allocator: Simple List Of Blocks
 *
 * Matt Mackall <mpm@selenic.com> 12/30/03
 *
 * How SLOB works:
 *
 * The core of SLOB is a traditional K&R style heap allocator, with
 * support for returning aligned objects. The granularity of this
 * allocator is 8 bytes on x86, though it's perhaps possible to reduce
 * this to 4 if it's deemed worth the effort. The slob heap is a
 * singly-linked list of pages from __get_free_page, grown on demand
 * and allocation from the heap is currently first-fit.
 *
 * Above this is an implementation of kmalloc/kfree. Blocks returned
 * from kmalloc are 8-byte aligned and prepended with a 8-byte header.
 * If kmalloc is asked for objects of PAGE_SIZE or larger, it calls
 * __get_free_pages directly so that it can return page-aligned blocks
 * and keeps a linked list of such pages and their orders. These
 * objects are detected in kfree() by their page alignment.
 *
 * SLAB is emulated on top of SLOB by simply calling constructors and
 * destructors for every SLAB allocation. Objects are returned with
 * the 8-byte alignment unless the SLAB_HWCACHE_ALIGN flag is
 * set, in which case the low-level allocator will fragment blocks to
 * create the proper alignment. Again, objects of page-size or greater
 * are allocated by calling __get_free_pages. As SLAB objects know
 * their size, no separate size bookkeeping is necessary and there is
 * essentially no allocation space overhead.
 */

#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/cache.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/timer.h>
#include <linux/rcupdate.h>

struct slob_block {
	int units;
	struct slob_block *next;
};
typedef struct slob_block slob_t;

#define SLOB_UNIT sizeof(slob_t)
#define SLOB_UNITS(size) (((size) + SLOB_UNIT - 1)/SLOB_UNIT)
#define SLOB_ALIGN L1_CACHE_BYTES

struct bigblock {
	int order;
	void *pages;
	struct bigblock *next;
};
typedef struct bigblock bigblock_t;

/*
 * struct slob_rcu is inserted at the tail of allocated slob blocks, which
 * were created with a SLAB_DESTROY_BY_RCU slab. slob_rcu is used to free
 * the block using call_rcu.
 */
struct slob_rcu {
	struct rcu_head head;
	int size;
};

static slob_t arena = { .next = &arena, .units = 1 };
static slob_t *slobfree = &arena;
static bigblock_t *bigblocks;
static DEFINE_SPINLOCK(slob_lock);
static DEFINE_SPINLOCK(block_lock);

static void slob_free(void *b, int size);
static void slob_timer_cbk(void);


static void *slob_alloc(size_t size, gfp_t gfp, int align)
{
	slob_t *prev, *cur, *aligned = 0;
	int delta = 0, units = SLOB_UNITS(size);
	unsigned long flags;

	spin_lock_irqsave(&slob_lock, flags);
	prev = slobfree;
	for (cur = prev->next; ; prev = cur, cur = cur->next) {
		if (align) {
			aligned = (slob_t *)ALIGN((unsigned long)cur, align);
			delta = aligned - cur;
		}
		if (cur->units >= units + delta) { /* room enough? */
			if (delta) { /* need to fragment head to align? */
				aligned->units = cur->units - delta;
				aligned->next = cur->next;
				cur->next = aligned;
				cur->units = delta;
				prev = cur;
				cur = aligned;
			}

			if (cur->units == units) /* exact fit? */
				prev->next = cur->next; /* unlink */
			else { /* fragment */
				prev->next = cur + units;
				prev->next->units = cur->units - units;
				prev->next->next = cur->next;
				cur->units = units;
			}

			slobfree = prev;
			spin_unlock_irqrestore(&slob_lock, flags);
			return cur;
		}
		if (cur == slobfree) {
			spin_unlock_irqrestore(&slob_lock, flags);

			if (size == PAGE_SIZE) /* trying to shrink arena? */
				return 0;

			cur = (slob_t *)__get_free_page(gfp);
			if (!cur)
				return 0;

			slob_free(cur, PAGE_SIZE);
			spin_lock_irqsave(&slob_lock, flags);
			cur = slobfree;
		}
	}
}

static void slob_free(void *block, int size)
{
	slob_t *cur, *b = (slob_t *)block;
	unsigned long flags;

	if (!block)
		return;

	if (size)
		b->units = SLOB_UNITS(size);

	/* Find reinsertion point */
	spin_lock_irqsave(&slob_lock, flags);
	for (cur = slobfree; !(b > cur && b < cur->next); cur = cur->next)
		if (cur >= cur->next && (b > cur || b < cur->next))
			break;

	if (b + b->units == cur->next) {
		b->units += cur->next->units;
		b->next = cur->next->next;
	} else
		b->next = cur->next;

	if (cur + cur->units == b) {
		cur->units += b->units;
		cur->next = b->next;
	} else
		cur->next = b;

	slobfree = cur;

	spin_unlock_irqrestore(&slob_lock, flags);
}

void *__kmalloc(size_t size, gfp_t gfp)
{
	slob_t *m;
	bigblock_t *bb;
	unsigned long flags;

	if (size < PAGE_SIZE - SLOB_UNIT) {
		m = slob_alloc(size + SLOB_UNIT, gfp, 0);
		return m ? (void *)(m + 1) : 0;
	}

	bb = slob_alloc(sizeof(bigblock_t), gfp, 0);
	if (!bb)
		return 0;

	bb->order = get_order(size);
	bb->pages = (void *)__get_free_pages(gfp, bb->order);

	if (bb->pages) {
		spin_lock_irqsave(&block_lock, flags);
		bb->next = bigblocks;
		bigblocks = bb;
		spin_unlock_irqrestore(&block_lock, flags);
		return bb->pages;
	}

	slob_free(bb, sizeof(bigblock_t));
	return 0;
}
EXPORT_SYMBOL(__kmalloc);

/**
 * krealloc - reallocate memory. The contents will remain unchanged.
 *
 * @p: object to reallocate memory for.
 * @new_size: how many bytes of memory are required.
 * @flags: the type of memory to allocate.
 *
 * The contents of the object pointed to are preserved up to the
 * lesser of the new and old sizes.  If @p is %NULL, krealloc()
 * behaves exactly like kmalloc().  If @size is 0 and @p is not a
 * %NULL pointer, the object pointed to is freed.
 */
void *krealloc(const void *p, size_t new_size, gfp_t flags)
{
	void *ret;

	if (unlikely(!p))
		return kmalloc_track_caller(new_size, flags);

	if (unlikely(!new_size)) {
		kfree(p);
		return NULL;
	}

	ret = kmalloc_track_caller(new_size, flags);
	if (ret) {
		memcpy(ret, p, min(new_size, ksize(p)));
		kfree(p);
	}
	return ret;
}
EXPORT_SYMBOL(krealloc);

void kfree(const void *block)
{
	bigblock_t *bb, **last = &bigblocks;
	unsigned long flags;

	if (!block)
		return;

	if (!((unsigned long)block & (PAGE_SIZE-1))) {
		/* might be on the big block list */
		spin_lock_irqsave(&block_lock, flags);
		for (bb = bigblocks; bb; last = &bb->next, bb = bb->next) {
			if (bb->pages == block) {
				*last = bb->next;
				spin_unlock_irqrestore(&block_lock, flags);
				free_pages((unsigned long)block, bb->order);
				slob_free(bb, sizeof(bigblock_t));
				return;
			}
		}
		spin_unlock_irqrestore(&block_lock, flags);
	}

	slob_free((slob_t *)block - 1, 0);
	return;
}

EXPORT_SYMBOL(kfree);

size_t ksize(const void *block)
{
	bigblock_t *bb;
	unsigned long flags;

	if (!block)
		return 0;

	if (!((unsigned long)block & (PAGE_SIZE-1))) {
		spin_lock_irqsave(&block_lock, flags);
		for (bb = bigblocks; bb; bb = bb->next)
			if (bb->pages == block) {
				spin_unlock_irqrestore(&slob_lock, flags);
				return PAGE_SIZE << bb->order;
			}
		spin_unlock_irqrestore(&block_lock, flags);
	}

	return ((slob_t *)block - 1)->units * SLOB_UNIT;
}

struct kmem_cache {
	unsigned int size, align;
	unsigned long flags;
	const char *name;
	void (*ctor)(void *, struct kmem_cache *, unsigned long);
};

struct kmem_cache *kmem_cache_create(const char *name, size_t size,
	size_t align, unsigned long flags,
	void (*ctor)(void*, struct kmem_cache *, unsigned long),
	void (*dtor)(void*, struct kmem_cache *, unsigned long))
{
	struct kmem_cache *c;

	c = slob_alloc(sizeof(struct kmem_cache), flags, 0);

	if (c) {
		c->name = name;
		c->size = size;
		if (flags & SLAB_DESTROY_BY_RCU) {
			/* leave room for rcu footer at the end of object */
			c->size += sizeof(struct slob_rcu);
		}
		c->flags = flags;
		c->ctor = ctor;
		/* ignore alignment unless it's forced */
		c->align = (flags & SLAB_HWCACHE_ALIGN) ? SLOB_ALIGN : 0;
		if (c->align < align)
			c->align = align;
	} else if (flags & SLAB_PANIC)
		panic("Cannot create slab cache %s\n", name);

	return c;
}
EXPORT_SYMBOL(kmem_cache_create);

void kmem_cache_destroy(struct kmem_cache *c)
{
	slob_free(c, sizeof(struct kmem_cache));
}
EXPORT_SYMBOL(kmem_cache_destroy);

void *kmem_cache_alloc(struct kmem_cache *c, gfp_t flags)
{
	void *b;

	if (c->size < PAGE_SIZE)
		b = slob_alloc(c->size, flags, c->align);
	else
		b = (void *)__get_free_pages(flags, get_order(c->size));

	if (c->ctor)
		c->ctor(b, c, 0);

	return b;
}
EXPORT_SYMBOL(kmem_cache_alloc);

void *kmem_cache_zalloc(struct kmem_cache *c, gfp_t flags)
{
	void *ret = kmem_cache_alloc(c, flags);
	if (ret)
		memset(ret, 0, c->size);

	return ret;
}
EXPORT_SYMBOL(kmem_cache_zalloc);

static void __kmem_cache_free(void *b, int size)
{
	if (size < PAGE_SIZE)
		slob_free(b, size);
	else
		free_pages((unsigned long)b, get_order(size));
}

static void kmem_rcu_free(struct rcu_head *head)
{
	struct slob_rcu *slob_rcu = (struct slob_rcu *)head;
	void *b = (void *)slob_rcu - (slob_rcu->size - sizeof(struct slob_rcu));

	__kmem_cache_free(b, slob_rcu->size);
}

void kmem_cache_free(struct kmem_cache *c, void *b)
{
	if (unlikely(c->flags & SLAB_DESTROY_BY_RCU)) {
		struct slob_rcu *slob_rcu;
		slob_rcu = b + (c->size - sizeof(struct slob_rcu));
		INIT_RCU_HEAD(&slob_rcu->head);
		slob_rcu->size = c->size;
		call_rcu(&slob_rcu->head, kmem_rcu_free);
	} else {
		__kmem_cache_free(b, c->size);
	}
}
EXPORT_SYMBOL(kmem_cache_free);

unsigned int kmem_cache_size(struct kmem_cache *c)
{
	return c->size;
}
EXPORT_SYMBOL(kmem_cache_size);

const char *kmem_cache_name(struct kmem_cache *c)
{
	return c->name;
}
EXPORT_SYMBOL(kmem_cache_name);

static struct timer_list slob_timer = TIMER_INITIALIZER(
	(void (*)(unsigned long))slob_timer_cbk, 0, 0);

int kmem_cache_shrink(struct kmem_cache *d)
{
	return 0;
}
EXPORT_SYMBOL(kmem_cache_shrink);

int kmem_ptr_validate(struct kmem_cache *a, const void *b)
{
	return 0;
}

void __init kmem_cache_init(void)
{
	slob_timer_cbk();
}

static void slob_timer_cbk(void)
{
	void *p = slob_alloc(PAGE_SIZE, 0, PAGE_SIZE-1);

	if (p)
		free_page((unsigned long)p);

	mod_timer(&slob_timer, jiffies + HZ);
}
Commit	Line	Data
10cef602 MM	1	/*
	2	* SLOB Allocator: Simple List Of Blocks
	3	*
	4	* Matt Mackall <mpm@selenic.com> 12/30/03
	5	*
	6	* How SLOB works:
	7	*
	8	* The core of SLOB is a traditional K&R style heap allocator, with
	9	* support for returning aligned objects. The granularity of this
	10	* allocator is 8 bytes on x86, though it's perhaps possible to reduce
	11	* this to 4 if it's deemed worth the effort. The slob heap is a
	12	* singly-linked list of pages from __get_free_page, grown on demand
	13	* and allocation from the heap is currently first-fit.
	14	*
	15	* Above this is an implementation of kmalloc/kfree. Blocks returned
	16	* from kmalloc are 8-byte aligned and prepended with a 8-byte header.
	17	* If kmalloc is asked for objects of PAGE_SIZE or larger, it calls
	18	* __get_free_pages directly so that it can return page-aligned blocks
	19	* and keeps a linked list of such pages and their orders. These
	20	* objects are detected in kfree() by their page alignment.
	21	*
	22	* SLAB is emulated on top of SLOB by simply calling constructors and
	23	* destructors for every SLAB allocation. Objects are returned with
5af60839	24	* the 8-byte alignment unless the SLAB_HWCACHE_ALIGN flag is
10cef602 MM	25	* set, in which case the low-level allocator will fragment blocks to
	26	* create the proper alignment. Again, objects of page-size or greater
	27	* are allocated by calling __get_free_pages. As SLAB objects know
	28	* their size, no separate size bookkeeping is necessary and there is
	29	* essentially no allocation space overhead.
	30	*/
	31
10cef602 MM	32	#include <linux/slab.h>
	33	#include <linux/mm.h>
	34	#include <linux/cache.h>
	35	#include <linux/init.h>
	36	#include <linux/module.h>
	37	#include <linux/timer.h>
afc0cedb	38	#include <linux/rcupdate.h>
10cef602 MM	39
	40	struct slob_block {
	41	int units;
	42	struct slob_block *next;
	43	};
	44	typedef struct slob_block slob_t;
	45
	46	#define SLOB_UNIT sizeof(slob_t)
	47	#define SLOB_UNITS(size) (((size) + SLOB_UNIT - 1)/SLOB_UNIT)
	48	#define SLOB_ALIGN L1_CACHE_BYTES
	49
	50	struct bigblock {
	51	int order;
	52	void *pages;
	53	struct bigblock *next;
	54	};
	55	typedef struct bigblock bigblock_t;
	56
afc0cedb NP	57	/*
	58	* struct slob_rcu is inserted at the tail of allocated slob blocks, which
	59	* were created with a SLAB_DESTROY_BY_RCU slab. slob_rcu is used to free
	60	* the block using call_rcu.
	61	*/
	62	struct slob_rcu {
	63	struct rcu_head head;
	64	int size;
	65	};
	66
10cef602 MM	67	static slob_t arena = { .next = &arena, .units = 1 };
	68	static slob_t *slobfree = &arena;
	69	static bigblock_t *bigblocks;
	70	static DEFINE_SPINLOCK(slob_lock);
	71	static DEFINE_SPINLOCK(block_lock);
	72
	73	static void slob_free(void *b, int size);
bcb4ddb4 DG	74	static void slob_timer_cbk(void);
bcb4ddb4 DG	75
10cef602 MM	76
	77	static void *slob_alloc(size_t size, gfp_t gfp, int align)
	78	{
	79	slob_t prev, cur, *aligned = 0;
	80	int delta = 0, units = SLOB_UNITS(size);
	81	unsigned long flags;
	82
	83	spin_lock_irqsave(&slob_lock, flags);
	84	prev = slobfree;
	85	for (cur = prev->next; ; prev = cur, cur = cur->next) {
	86	if (align) {
	87	aligned = (slob_t *)ALIGN((unsigned long)cur, align);
	88	delta = aligned - cur;
	89	}
	90	if (cur->units >= units + delta) { /* room enough? */
	91	if (delta) { /* need to fragment head to align? */
	92	aligned->units = cur->units - delta;
	93	aligned->next = cur->next;
	94	cur->next = aligned;
	95	cur->units = delta;
	96	prev = cur;
	97	cur = aligned;
	98	}
	99
	100	if (cur->units == units) /* exact fit? */
	101	prev->next = cur->next; /* unlink */
	102	else { /* fragment */
	103	prev->next = cur + units;
	104	prev->next->units = cur->units - units;
	105	prev->next->next = cur->next;
	106	cur->units = units;
	107	}
	108
	109	slobfree = prev;
	110	spin_unlock_irqrestore(&slob_lock, flags);
	111	return cur;
	112	}
	113	if (cur == slobfree) {
	114	spin_unlock_irqrestore(&slob_lock, flags);
	115
	116	if (size == PAGE_SIZE) /* trying to shrink arena? */
	117	return 0;
	118
	119	cur = (slob_t *)__get_free_page(gfp);
	120	if (!cur)
	121	return 0;
	122
	123	slob_free(cur, PAGE_SIZE);
	124	spin_lock_irqsave(&slob_lock, flags);
	125	cur = slobfree;
	126	}
	127	}
	128	}
	129
	130	static void slob_free(void *block, int size)
	131	{
	132	slob_t cur, b = (slob_t *)block;
	133	unsigned long flags;
	134
	135	if (!block)
	136	return;
	137
	138	if (size)
	139	b->units = SLOB_UNITS(size);
140
141	/* Find reinsertion point */
142	spin_lock_irqsave(&slob_lock, flags);
143	for (cur = slobfree; !(b > cur && b < cur->next); cur = cur->next)
144	if (cur >= cur->next && (b > cur \|\| b < cur->next))
145	break;
146
147	if (b + b->units == cur->next) {
148	b->units += cur->next->units;
149	b->next = cur->next->next;
150	} else
151	b->next = cur->next;
152
153	if (cur + cur->units == b) {
154	cur->units += b->units;
155	cur->next = b->next;
156	} else
157	cur->next = b;
158
159	slobfree = cur;
160
161	spin_unlock_irqrestore(&slob_lock, flags);
162	}
163
2e892f43	164	void *__kmalloc(size_t size, gfp_t gfp)
10cef602 MM	165	{
	166	slob_t *m;
	167	bigblock_t *bb;
	168	unsigned long flags;
	169
	170	if (size < PAGE_SIZE - SLOB_UNIT) {
	171	m = slob_alloc(size + SLOB_UNIT, gfp, 0);
	172	return m ? (void *)(m + 1) : 0;
	173	}
	174
	175	bb = slob_alloc(sizeof(bigblock_t), gfp, 0);
	176	if (!bb)
	177	return 0;
	178
4ab688c5	179	bb->order = get_order(size);
10cef602 MM	180	bb->pages = (void *)__get_free_pages(gfp, bb->order);
	181
	182	if (bb->pages) {
	183	spin_lock_irqsave(&block_lock, flags);
	184	bb->next = bigblocks;
	185	bigblocks = bb;
	186	spin_unlock_irqrestore(&block_lock, flags);
	187	return bb->pages;
	188	}
	189
	190	slob_free(bb, sizeof(bigblock_t));
	191	return 0;
	192	}
2e892f43	193	EXPORT_SYMBOL(__kmalloc);
10cef602	194
fd76bab2 PE	195	/**
	196	* krealloc - reallocate memory. The contents will remain unchanged.
	197	*
	198	* @p: object to reallocate memory for.
	199	* @new_size: how many bytes of memory are required.
	200	* @flags: the type of memory to allocate.
	201	*
	202	* The contents of the object pointed to are preserved up to the
	203	* lesser of the new and old sizes. If @p is %NULL, krealloc()
	204	* behaves exactly like kmalloc(). If @size is 0 and @p is not a
	205	* %NULL pointer, the object pointed to is freed.
	206	*/
	207	void krealloc(const void p, size_t new_size, gfp_t flags)
	208	{
	209	void *ret;
	210
	211	if (unlikely(!p))
	212	return kmalloc_track_caller(new_size, flags);
	213
	214	if (unlikely(!new_size)) {
	215	kfree(p);
	216	return NULL;
	217	}
	218
	219	ret = kmalloc_track_caller(new_size, flags);
	220	if (ret) {
	221	memcpy(ret, p, min(new_size, ksize(p)));
	222	kfree(p);
	223	}
	224	return ret;
	225	}
	226	EXPORT_SYMBOL(krealloc);
	227
10cef602 MM	228	void kfree(const void *block)
	229	{
	230	bigblock_t bb, *last = &bigblocks;
	231	unsigned long flags;
	232
	233	if (!block)
	234	return;
	235
	236	if (!((unsigned long)block & (PAGE_SIZE-1))) {
	237	/* might be on the big block list */
	238	spin_lock_irqsave(&block_lock, flags);
	239	for (bb = bigblocks; bb; last = &bb->next, bb = bb->next) {
	240	if (bb->pages == block) {
	241	*last = bb->next;
	242	spin_unlock_irqrestore(&block_lock, flags);
	243	free_pages((unsigned long)block, bb->order);
	244	slob_free(bb, sizeof(bigblock_t));
	245	return;
	246	}
	247	}
	248	spin_unlock_irqrestore(&block_lock, flags);
	249	}
	250
	251	slob_free((slob_t *)block - 1, 0);
	252	return;
	253	}
	254
	255	EXPORT_SYMBOL(kfree);
	256
fd76bab2	257	size_t ksize(const void *block)
10cef602 MM	258	{
	259	bigblock_t *bb;
	260	unsigned long flags;
	261
	262	if (!block)
	263	return 0;
	264
	265	if (!((unsigned long)block & (PAGE_SIZE-1))) {
	266	spin_lock_irqsave(&block_lock, flags);
	267	for (bb = bigblocks; bb; bb = bb->next)
	268	if (bb->pages == block) {
	269	spin_unlock_irqrestore(&slob_lock, flags);
	270	return PAGE_SIZE << bb->order;
	271	}
	272	spin_unlock_irqrestore(&block_lock, flags);
	273	}
	274
	275	return ((slob_t )block - 1)->units SLOB_UNIT;
	276	}
	277
	278	struct kmem_cache {
	279	unsigned int size, align;
afc0cedb	280	unsigned long flags;
10cef602 MM	281	const char *name;
10cef602 MM	282	void (ctor)(void , struct kmem_cache *, unsigned long);
10cef602 MM	283	};
	284
	285	struct kmem_cache kmem_cache_create(const char name, size_t size,
	286	size_t align, unsigned long flags,
	287	void (ctor)(void, struct kmem_cache *, unsigned long),
	288	void (dtor)(void, struct kmem_cache *, unsigned long))
	289	{
	290	struct kmem_cache *c;
	291
	292	c = slob_alloc(sizeof(struct kmem_cache), flags, 0);
	293
	294	if (c) {
	295	c->name = name;
	296	c->size = size;
afc0cedb	297	if (flags & SLAB_DESTROY_BY_RCU) {
afc0cedb NP	298	/* leave room for rcu footer at the end of object */
	299	c->size += sizeof(struct slob_rcu);
	300	}
	301	c->flags = flags;
10cef602	302	c->ctor = ctor;
10cef602	303	/* ignore alignment unless it's forced */
5af60839	304	c->align = (flags & SLAB_HWCACHE_ALIGN) ? SLOB_ALIGN : 0;
10cef602 MM	305	if (c->align < align)
10cef602 MM	306	c->align = align;
bc0055ae AM	307	} else if (flags & SLAB_PANIC)
bc0055ae AM	308	panic("Cannot create slab cache %s\n", name);
10cef602 MM	309
	310	return c;
	311	}
	312	EXPORT_SYMBOL(kmem_cache_create);
	313
133d205a	314	void kmem_cache_destroy(struct kmem_cache *c)
10cef602 MM	315	{
10cef602 MM	316	slob_free(c, sizeof(struct kmem_cache));
10cef602 MM	317	}
	318	EXPORT_SYMBOL(kmem_cache_destroy);
	319
	320	void kmem_cache_alloc(struct kmem_cache c, gfp_t flags)
	321	{
	322	void *b;
	323
	324	if (c->size < PAGE_SIZE)
	325	b = slob_alloc(c->size, flags, c->align);
	326	else
4ab688c5	327	b = (void *)__get_free_pages(flags, get_order(c->size));
10cef602 MM	328
10cef602 MM	329	if (c->ctor)
a35afb83	330	c->ctor(b, c, 0);
10cef602 MM	331
	332	return b;
	333	}
	334	EXPORT_SYMBOL(kmem_cache_alloc);
	335
a8c0f9a4 PE	336	void kmem_cache_zalloc(struct kmem_cache c, gfp_t flags)
	337	{
	338	void *ret = kmem_cache_alloc(c, flags);
	339	if (ret)
	340	memset(ret, 0, c->size);
	341
	342	return ret;
	343	}
	344	EXPORT_SYMBOL(kmem_cache_zalloc);
	345
afc0cedb	346	static void __kmem_cache_free(void *b, int size)
10cef602	347	{
afc0cedb NP	348	if (size < PAGE_SIZE)
afc0cedb NP	349	slob_free(b, size);
10cef602	350	else
afc0cedb NP	351	free_pages((unsigned long)b, get_order(size));
	352	}
	353
	354	static void kmem_rcu_free(struct rcu_head *head)
	355	{
	356	struct slob_rcu slob_rcu = (struct slob_rcu )head;
	357	void b = (void )slob_rcu - (slob_rcu->size - sizeof(struct slob_rcu));
	358
	359	__kmem_cache_free(b, slob_rcu->size);
	360	}
	361
	362	void kmem_cache_free(struct kmem_cache c, void b)
	363	{
	364	if (unlikely(c->flags & SLAB_DESTROY_BY_RCU)) {
	365	struct slob_rcu *slob_rcu;
	366	slob_rcu = b + (c->size - sizeof(struct slob_rcu));
	367	INIT_RCU_HEAD(&slob_rcu->head);
	368	slob_rcu->size = c->size;
	369	call_rcu(&slob_rcu->head, kmem_rcu_free);
	370	} else {
afc0cedb NP	371	__kmem_cache_free(b, c->size);
afc0cedb NP	372	}
10cef602 MM	373	}
	374	EXPORT_SYMBOL(kmem_cache_free);
	375
	376	unsigned int kmem_cache_size(struct kmem_cache *c)
	377	{
	378	return c->size;
	379	}
	380	EXPORT_SYMBOL(kmem_cache_size);
	381
	382	const char kmem_cache_name(struct kmem_cache c)
	383	{
	384	return c->name;
	385	}
	386	EXPORT_SYMBOL(kmem_cache_name);
	387
	388	static struct timer_list slob_timer = TIMER_INITIALIZER(
bcb4ddb4	389	(void (*)(unsigned long))slob_timer_cbk, 0, 0);
10cef602	390
2e892f43 CL	391	int kmem_cache_shrink(struct kmem_cache *d)
	392	{
	393	return 0;
	394	}
	395	EXPORT_SYMBOL(kmem_cache_shrink);
	396
55935a34	397	int kmem_ptr_validate(struct kmem_cache a, const void b)
2e892f43 CL	398	{
	399	return 0;
	400	}
	401
bcb4ddb4 DG	402	void __init kmem_cache_init(void)
	403	{
	404	slob_timer_cbk();
	405	}
	406
	407	static void slob_timer_cbk(void)
10cef602 MM	408	{
	409	void *p = slob_alloc(PAGE_SIZE, 0, PAGE_SIZE-1);
	410
	411	if (p)
	412	free_page((unsigned long)p);
	413
	414	mod_timer(&slob_timer, jiffies + HZ);
	415	}