[fio.git] / smalloc.c

/*
 * simple memory allocator, backed by mmap() so that it hands out memory
 * that can be shared across processes and threads
 */
#include <sys/mman.h>
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <limits.h>
#include <fcntl.h>

#include "mutex.h"
#include "arch/arch.h"
#include "os/os.h"

#define SMALLOC_REDZONE		/* define to detect memory corruption */

#define SMALLOC_BPB	32	/* block size, bytes-per-bit in bitmap */
#define SMALLOC_BPI	(sizeof(unsigned int) * 8)
#define SMALLOC_BPL	(SMALLOC_BPB * SMALLOC_BPI)

#define INITIAL_SIZE	8192*1024	/* new pool size */
#define MAX_POOLS	128		/* maximum number of pools to setup */

#define SMALLOC_PRE_RED		0xdeadbeefU
#define SMALLOC_POST_RED	0x5aa55aa5U

unsigned int smalloc_pool_size = INITIAL_SIZE;
const int int_mask = sizeof(int) - 1;

struct pool {
	struct fio_mutex *lock;			/* protects this pool */
	void *map;				/* map of blocks */
	unsigned int *bitmap;			/* blocks free/busy map */
	unsigned int free_blocks;		/* free blocks */
	unsigned int nr_blocks;			/* total blocks */
	unsigned int next_non_full;
	unsigned int mmap_size;
};

struct block_hdr {
	unsigned int size;
#ifdef SMALLOC_REDZONE
	unsigned int prered;
#endif
};

static struct pool mp[MAX_POOLS];
static unsigned int nr_pools;
static unsigned int last_pool;
static struct fio_mutex *lock;

static inline void pool_lock(struct pool *pool)
{
	fio_mutex_down(pool->lock);
}

static inline void pool_unlock(struct pool *pool)
{
	fio_mutex_up(pool->lock);
}

static inline void global_read_lock(void)
{
	fio_mutex_down_read(lock);
}

static inline void global_read_unlock(void)
{
	fio_mutex_up_read(lock);
}

static inline void global_write_lock(void)
{
	fio_mutex_down_write(lock);
}

static inline void global_write_unlock(void)
{
	fio_mutex_up_write(lock);
}

static inline int ptr_valid(struct pool *pool, void *ptr)
{
	unsigned int pool_size = pool->nr_blocks * SMALLOC_BPL;

	return (ptr >= pool->map) && (ptr < pool->map + pool_size);
}

static inline unsigned int size_to_blocks(unsigned int size)
{
	return (size + SMALLOC_BPB - 1) / SMALLOC_BPB;
}

static int blocks_iter(struct pool *pool, unsigned int pool_idx,
		       unsigned int idx, unsigned int nr_blocks,
		       int (*func)(unsigned int *map, unsigned int mask))
{

	while (nr_blocks) {
		unsigned int this_blocks, mask;
		unsigned int *map;

		if (pool_idx >= pool->nr_blocks)
			return 0;

		map = &pool->bitmap[pool_idx];

		this_blocks = nr_blocks;
		if (this_blocks + idx > SMALLOC_BPI) {
			this_blocks = SMALLOC_BPI - idx;
			idx = SMALLOC_BPI - this_blocks;
		}

		if (this_blocks == SMALLOC_BPI)
			mask = -1U;
		else
			mask = ((1U << this_blocks) - 1) << idx;

		if (!func(map, mask))
			return 0;

		nr_blocks -= this_blocks;
		idx = 0;
		pool_idx++;
	}

	return 1;
}

static int mask_cmp(unsigned int *map, unsigned int mask)
{
	return !(*map & mask);
}

static int mask_clear(unsigned int *map, unsigned int mask)
{
	assert((*map & mask) == mask);
	*map &= ~mask;
	return 1;
}

static int mask_set(unsigned int *map, unsigned int mask)
{
	assert(!(*map & mask));
	*map |= mask;
	return 1;
}

static int blocks_free(struct pool *pool, unsigned int pool_idx,
		       unsigned int idx, unsigned int nr_blocks)
{
	return blocks_iter(pool, pool_idx, idx, nr_blocks, mask_cmp);
}

static void set_blocks(struct pool *pool, unsigned int pool_idx,
		       unsigned int idx, unsigned int nr_blocks)
{
	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_set);
}

static void clear_blocks(struct pool *pool, unsigned int pool_idx,
			 unsigned int idx, unsigned int nr_blocks)
{
	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_clear);
}

static int find_next_zero(int word, int start)
{
	assert(word != -1U);
	word >>= start;
	return ffz(word) + start;
}

static int add_pool(struct pool *pool, unsigned int alloc_size)
{
	int bitmap_blocks;
	void *ptr;

#ifdef SMALLOC_REDZONE
	alloc_size += sizeof(unsigned int);
#endif
	alloc_size += sizeof(struct block_hdr);
	if (alloc_size < INITIAL_SIZE)
		alloc_size = INITIAL_SIZE;

	/* round up to nearest full number of blocks */
	alloc_size = (alloc_size + SMALLOC_BPL - 1) & ~(SMALLOC_BPL - 1);
	bitmap_blocks = alloc_size / SMALLOC_BPL;
	alloc_size += bitmap_blocks * sizeof(unsigned int);
	pool->mmap_size = alloc_size;

	pool->nr_blocks = bitmap_blocks;
	pool->free_blocks = bitmap_blocks * SMALLOC_BPB;

	ptr = mmap(NULL, alloc_size, PROT_READ|PROT_WRITE,
			MAP_SHARED | OS_MAP_ANON, -1, 0);
	if (ptr == MAP_FAILED)
		goto out_fail;

	memset(ptr, 0, alloc_size);
	pool->map = ptr;
	pool->bitmap = (void *) ptr + (pool->nr_blocks * SMALLOC_BPL);

	pool->lock = fio_mutex_init(1);
	if (!pool->lock)
		goto out_fail;

	nr_pools++;
	return 0;
out_fail:
	fprintf(stderr, "smalloc: failed adding pool\n");
	if (pool->map)
		munmap(pool->map, pool->mmap_size);
	return 1;
}

void sinit(void)
{
	int ret;

	lock = fio_mutex_rw_init();
	ret = add_pool(&mp[0], INITIAL_SIZE);
	assert(!ret);
}

static void cleanup_pool(struct pool *pool)
{
	/*
	 * This will also remove the temporary file we used as a backing
	 * store, it was already unlinked
	 */
	munmap(pool->map, pool->mmap_size);

	if (pool->lock)
		fio_mutex_remove(pool->lock);
}

void scleanup(void)
{
	unsigned int i;

	for (i = 0; i < nr_pools; i++)
		cleanup_pool(&mp[i]);

	if (lock)
		fio_mutex_remove(lock);
}

#ifdef SMALLOC_REDZONE
static void *postred_ptr(struct block_hdr *hdr)
{
	unsigned long ptr;

	ptr = (unsigned long) hdr + hdr->size - sizeof(unsigned int);
	ptr = (ptr + int_mask) & ~int_mask;

	return (void *) ptr;
}

static void fill_redzone(struct block_hdr *hdr)
{
	unsigned int *postred = postred_ptr(hdr);

	hdr->prered = SMALLOC_PRE_RED;
	*postred = SMALLOC_POST_RED;
}

static void sfree_check_redzone(struct block_hdr *hdr)
{
	unsigned int *postred = postred_ptr(hdr);

	if (hdr->prered != SMALLOC_PRE_RED) {
		fprintf(stderr, "smalloc pre redzone destroyed!\n");
		fprintf(stderr, "  ptr=%p, prered=%x, expected %x\n",
				hdr, hdr->prered, SMALLOC_PRE_RED);
		assert(0);
	}
	if (*postred != SMALLOC_POST_RED) {
		fprintf(stderr, "smalloc post redzone destroyed!\n");
		fprintf(stderr, "  ptr=%p, postred=%x, expected %x\n",
				hdr, *postred, SMALLOC_POST_RED);
		assert(0);
	}
}
#else
static void fill_redzone(struct block_hdr *hdr)
{
}

static void sfree_check_redzone(struct block_hdr *hdr)
{
}
#endif

static void sfree_pool(struct pool *pool, void *ptr)
{
	struct block_hdr *hdr;
	unsigned int i, idx;
	unsigned long offset;

	if (!ptr)
		return;

	ptr -= sizeof(*hdr);
	hdr = ptr;

	assert(ptr_valid(pool, ptr));

	sfree_check_redzone(hdr);

	offset = ptr - pool->map;
	i = offset / SMALLOC_BPL;
	idx = (offset % SMALLOC_BPL) / SMALLOC_BPB;

	pool_lock(pool);
	clear_blocks(pool, i, idx, size_to_blocks(hdr->size));
	if (i < pool->next_non_full)
		pool->next_non_full = i;
	pool->free_blocks += size_to_blocks(hdr->size);
	pool_unlock(pool);
}

void sfree(void *ptr)
{
	struct pool *pool = NULL;
	unsigned int i;

	if (!ptr)
		return;

	global_read_lock();

	for (i = 0; i < nr_pools; i++) {
		if (ptr_valid(&mp[i], ptr)) {
			pool = &mp[i];
			break;
		}
	}

	global_read_unlock();

	assert(pool);
	sfree_pool(pool, ptr);
}

static void *__smalloc_pool(struct pool *pool, unsigned int size)
{
	unsigned int nr_blocks;
	unsigned int i;
	unsigned int offset;
	unsigned int last_idx;
	void *ret = NULL;

	pool_lock(pool);

	nr_blocks = size_to_blocks(size);
	if (nr_blocks > pool->free_blocks)
		goto fail;

	i = pool->next_non_full;
	last_idx = 0;
	offset = -1U;
	while (i < pool->nr_blocks) {
		unsigned int idx;

		if (pool->bitmap[i] == -1U) {
			i++;
			pool->next_non_full = i;
			last_idx = 0;
			continue;
		}

		idx = find_next_zero(pool->bitmap[i], last_idx);
		if (!blocks_free(pool, i, idx, nr_blocks)) {
			idx += nr_blocks;
			if (idx < SMALLOC_BPI)
				last_idx = idx;
			else {
				last_idx = 0;
				while (idx >= SMALLOC_BPI) {
					i++;
					idx -= SMALLOC_BPI;
				}
			}
			continue;
		}
		set_blocks(pool, i, idx, nr_blocks);
		offset = i * SMALLOC_BPL + idx * SMALLOC_BPB;
		break;
	}

	if (i < pool->nr_blocks) {
		pool->free_blocks -= nr_blocks;
		ret = pool->map + offset;
	}
fail:
	pool_unlock(pool);
	return ret;
}

static void *smalloc_pool(struct pool *pool, unsigned int size)
{
	unsigned int alloc_size = size + sizeof(struct block_hdr);
	void *ptr;

	/*
	 * Round to int alignment, so that the postred pointer will
	 * be naturally aligned as well.
	 */
#ifdef SMALLOC_REDZONE
	alloc_size += sizeof(unsigned int);
	alloc_size = (alloc_size + int_mask) & ~int_mask;
#endif

	ptr = __smalloc_pool(pool, alloc_size);
	if (ptr) {
		struct block_hdr *hdr = ptr;

		hdr->size = alloc_size;
		fill_redzone(hdr);

		ptr += sizeof(*hdr);
		memset(ptr, 0, size);
	}

	return ptr;
}

void *smalloc(unsigned int size)
{
	unsigned int i;

	global_write_lock();
	i = last_pool;

	do {
		for (; i < nr_pools; i++) {
			void *ptr = smalloc_pool(&mp[i], size);

			if (ptr) {
				last_pool = i;
				global_write_unlock();
				return ptr;
			}
		}
		if (last_pool) {
			last_pool = 0;
			continue;
		}

		if (nr_pools + 1 > MAX_POOLS)
			break;
		else {
			i = nr_pools;
			if (add_pool(&mp[nr_pools], size))
				goto out;
		}
	} while (1);

out:
	global_write_unlock();
	return NULL;
}

char *smalloc_strdup(const char *str)
{
	char *ptr;

	ptr = smalloc(strlen(str) + 1);
	strcpy(ptr, str);
	return ptr;
}
Commit	Line	Data
	1	/*
	2	* simple memory allocator, backed by mmap() so that it hands out memory
	3	* that can be shared across processes and threads
	4	*/
	5	#include <sys/mman.h>
	6	#include <stdio.h>
	7	#include <stdlib.h>
	8	#include <assert.h>
	9	#include <string.h>
	10	#include <unistd.h>
	11	#include <sys/types.h>
	12	#include <limits.h>
	13	#include <fcntl.h>
	14
	15	#include "mutex.h"
	16	#include "arch/arch.h"
	17	#include "os/os.h"
	18
	19	#define SMALLOC_REDZONE /* define to detect memory corruption */
	20
	21	#define SMALLOC_BPB 32 /* block size, bytes-per-bit in bitmap */
	22	#define SMALLOC_BPI (sizeof(unsigned int) * 8)
	23	#define SMALLOC_BPL (SMALLOC_BPB * SMALLOC_BPI)
	24
	25	#define INITIAL_SIZE 81921024 / new pool size */
	26	#define MAX_POOLS 128 /* maximum number of pools to setup */
	27
	28	#define SMALLOC_PRE_RED 0xdeadbeefU
	29	#define SMALLOC_POST_RED 0x5aa55aa5U
	30
	31	unsigned int smalloc_pool_size = INITIAL_SIZE;
	32	const int int_mask = sizeof(int) - 1;
	33
	34	struct pool {
	35	struct fio_mutex lock; / protects this pool */
	36	void map; / map of blocks */
	37	unsigned int bitmap; / blocks free/busy map */
	38	unsigned int free_blocks; /* free blocks */
	39	unsigned int nr_blocks; /* total blocks */
	40	unsigned int next_non_full;
	41	unsigned int mmap_size;
	42	};
	43
	44	struct block_hdr {
	45	unsigned int size;
	46	#ifdef SMALLOC_REDZONE
	47	unsigned int prered;
	48	#endif
	49	};
	50
	51	static struct pool mp[MAX_POOLS];
	52	static unsigned int nr_pools;
	53	static unsigned int last_pool;
	54	static struct fio_mutex *lock;
	55
	56	static inline void pool_lock(struct pool *pool)
	57	{
	58	fio_mutex_down(pool->lock);
	59	}
	60
	61	static inline void pool_unlock(struct pool *pool)
	62	{
	63	fio_mutex_up(pool->lock);
	64	}
	65
	66	static inline void global_read_lock(void)
	67	{
	68	fio_mutex_down_read(lock);
	69	}
	70
	71	static inline void global_read_unlock(void)
	72	{
	73	fio_mutex_up_read(lock);
	74	}
	75
	76	static inline void global_write_lock(void)
	77	{
	78	fio_mutex_down_write(lock);
	79	}
	80
	81	static inline void global_write_unlock(void)
	82	{
	83	fio_mutex_up_write(lock);
	84	}
	85
	86	static inline int ptr_valid(struct pool pool, void ptr)
	87	{
	88	unsigned int pool_size = pool->nr_blocks * SMALLOC_BPL;
	89
	90	return (ptr >= pool->map) && (ptr < pool->map + pool_size);
	91	}
	92
	93	static inline unsigned int size_to_blocks(unsigned int size)
	94	{
	95	return (size + SMALLOC_BPB - 1) / SMALLOC_BPB;
	96	}
	97
	98	static int blocks_iter(struct pool *pool, unsigned int pool_idx,
	99	unsigned int idx, unsigned int nr_blocks,
	100	int (func)(unsigned int map, unsigned int mask))
	101	{
	102
	103	while (nr_blocks) {
	104	unsigned int this_blocks, mask;
	105	unsigned int *map;
	106
	107	if (pool_idx >= pool->nr_blocks)
	108	return 0;
	109
	110	map = &pool->bitmap[pool_idx];
	111
	112	this_blocks = nr_blocks;
	113	if (this_blocks + idx > SMALLOC_BPI) {
	114	this_blocks = SMALLOC_BPI - idx;
	115	idx = SMALLOC_BPI - this_blocks;
	116	}
	117
	118	if (this_blocks == SMALLOC_BPI)
	119	mask = -1U;
	120	else
	121	mask = ((1U << this_blocks) - 1) << idx;
	122
	123	if (!func(map, mask))
	124	return 0;
	125
	126	nr_blocks -= this_blocks;
	127	idx = 0;
	128	pool_idx++;
	129	}
	130
	131	return 1;
	132	}
	133
	134	static int mask_cmp(unsigned int *map, unsigned int mask)
	135	{
	136	return !(*map & mask);
	137	}
	138
	139	static int mask_clear(unsigned int *map, unsigned int mask)
	140	{
	141	assert((*map & mask) == mask);
	142	*map &= ~mask;
	143	return 1;
	144	}
	145
	146	static int mask_set(unsigned int *map, unsigned int mask)
	147	{
	148	assert(!(*map & mask));
	149	*map \|= mask;
	150	return 1;
	151	}
	152
	153	static int blocks_free(struct pool *pool, unsigned int pool_idx,
	154	unsigned int idx, unsigned int nr_blocks)
	155	{
	156	return blocks_iter(pool, pool_idx, idx, nr_blocks, mask_cmp);
	157	}
	158
	159	static void set_blocks(struct pool *pool, unsigned int pool_idx,
	160	unsigned int idx, unsigned int nr_blocks)
	161	{
	162	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_set);
	163	}
	164
	165	static void clear_blocks(struct pool *pool, unsigned int pool_idx,
	166	unsigned int idx, unsigned int nr_blocks)
	167	{
	168	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_clear);
	169	}
	170
	171	static int find_next_zero(int word, int start)
	172	{
	173	assert(word != -1U);
	174	word >>= start;
	175	return ffz(word) + start;
	176	}
	177
	178	static int add_pool(struct pool *pool, unsigned int alloc_size)
	179	{
	180	int bitmap_blocks;
	181	void *ptr;
	182
	183	#ifdef SMALLOC_REDZONE
	184	alloc_size += sizeof(unsigned int);
	185	#endif
	186	alloc_size += sizeof(struct block_hdr);
	187	if (alloc_size < INITIAL_SIZE)
	188	alloc_size = INITIAL_SIZE;
	189
	190	/* round up to nearest full number of blocks */
	191	alloc_size = (alloc_size + SMALLOC_BPL - 1) & ~(SMALLOC_BPL - 1);
	192	bitmap_blocks = alloc_size / SMALLOC_BPL;
	193	alloc_size += bitmap_blocks * sizeof(unsigned int);
	194	pool->mmap_size = alloc_size;
	195
	196	pool->nr_blocks = bitmap_blocks;
	197	pool->free_blocks = bitmap_blocks * SMALLOC_BPB;
	198
	199	ptr = mmap(NULL, alloc_size, PROT_READ\|PROT_WRITE,
	200	MAP_SHARED \| OS_MAP_ANON, -1, 0);
	201	if (ptr == MAP_FAILED)
	202	goto out_fail;
	203
	204	memset(ptr, 0, alloc_size);
	205	pool->map = ptr;
	206	pool->bitmap = (void ) ptr + (pool->nr_blocks SMALLOC_BPL);
	207
	208	pool->lock = fio_mutex_init(1);
	209	if (!pool->lock)
	210	goto out_fail;
	211
	212	nr_pools++;
	213	return 0;
	214	out_fail:
	215	fprintf(stderr, "smalloc: failed adding pool\n");
	216	if (pool->map)
	217	munmap(pool->map, pool->mmap_size);
	218	return 1;
	219	}
	220
	221	void sinit(void)
	222	{
	223	int ret;
	224
	225	lock = fio_mutex_rw_init();
	226	ret = add_pool(&mp[0], INITIAL_SIZE);
	227	assert(!ret);
	228	}
	229
	230	static void cleanup_pool(struct pool *pool)
	231	{
	232	/*
	233	* This will also remove the temporary file we used as a backing
	234	* store, it was already unlinked
	235	*/
	236	munmap(pool->map, pool->mmap_size);
	237
	238	if (pool->lock)
	239	fio_mutex_remove(pool->lock);
	240	}
	241
	242	void scleanup(void)
	243	{
	244	unsigned int i;
	245
	246	for (i = 0; i < nr_pools; i++)
	247	cleanup_pool(&mp[i]);
	248
	249	if (lock)
	250	fio_mutex_remove(lock);
	251	}
	252
	253	#ifdef SMALLOC_REDZONE
	254	static void postred_ptr(struct block_hdr hdr)
	255	{
	256	unsigned long ptr;
	257
	258	ptr = (unsigned long) hdr + hdr->size - sizeof(unsigned int);
	259	ptr = (ptr + int_mask) & ~int_mask;
	260
	261	return (void *) ptr;
	262	}
	263
	264	static void fill_redzone(struct block_hdr *hdr)
	265	{
	266	unsigned int *postred = postred_ptr(hdr);
	267
	268	hdr->prered = SMALLOC_PRE_RED;
	269	*postred = SMALLOC_POST_RED;
	270	}
	271
	272	static void sfree_check_redzone(struct block_hdr *hdr)
	273	{
	274	unsigned int *postred = postred_ptr(hdr);
	275
	276	if (hdr->prered != SMALLOC_PRE_RED) {
	277	fprintf(stderr, "smalloc pre redzone destroyed!\n");
	278	fprintf(stderr, " ptr=%p, prered=%x, expected %x\n",
	279	hdr, hdr->prered, SMALLOC_PRE_RED);
	280	assert(0);
	281	}
	282	if (*postred != SMALLOC_POST_RED) {
	283	fprintf(stderr, "smalloc post redzone destroyed!\n");
	284	fprintf(stderr, " ptr=%p, postred=%x, expected %x\n",
	285	hdr, *postred, SMALLOC_POST_RED);
	286	assert(0);
	287	}
	288	}
	289	#else
	290	static void fill_redzone(struct block_hdr *hdr)
	291	{
	292	}
	293
	294	static void sfree_check_redzone(struct block_hdr *hdr)
	295	{
	296	}
	297	#endif
	298
	299	static void sfree_pool(struct pool pool, void ptr)
	300	{
	301	struct block_hdr *hdr;
	302	unsigned int i, idx;
	303	unsigned long offset;
	304
	305	if (!ptr)
	306	return;
	307
	308	ptr -= sizeof(*hdr);
	309	hdr = ptr;
	310
	311	assert(ptr_valid(pool, ptr));
	312
	313	sfree_check_redzone(hdr);
	314
	315	offset = ptr - pool->map;
	316	i = offset / SMALLOC_BPL;
	317	idx = (offset % SMALLOC_BPL) / SMALLOC_BPB;
	318
	319	pool_lock(pool);
	320	clear_blocks(pool, i, idx, size_to_blocks(hdr->size));
	321	if (i < pool->next_non_full)
	322	pool->next_non_full = i;
	323	pool->free_blocks += size_to_blocks(hdr->size);
	324	pool_unlock(pool);
	325	}
	326
	327	void sfree(void *ptr)
	328	{
	329	struct pool *pool = NULL;
	330	unsigned int i;
	331
	332	if (!ptr)
	333	return;
	334
	335	global_read_lock();
	336
	337	for (i = 0; i < nr_pools; i++) {
	338	if (ptr_valid(&mp[i], ptr)) {
	339	pool = &mp[i];
	340	break;
	341	}
	342	}
	343
	344	global_read_unlock();
	345
	346	assert(pool);
	347	sfree_pool(pool, ptr);
	348	}
	349
	350	static void __smalloc_pool(struct pool pool, unsigned int size)
	351	{
	352	unsigned int nr_blocks;
	353	unsigned int i;
	354	unsigned int offset;
	355	unsigned int last_idx;
	356	void *ret = NULL;
	357
	358	pool_lock(pool);
	359
	360	nr_blocks = size_to_blocks(size);
	361	if (nr_blocks > pool->free_blocks)
	362	goto fail;
	363
	364	i = pool->next_non_full;
	365	last_idx = 0;
	366	offset = -1U;
	367	while (i < pool->nr_blocks) {
	368	unsigned int idx;
	369
	370	if (pool->bitmap[i] == -1U) {
	371	i++;
	372	pool->next_non_full = i;
	373	last_idx = 0;
	374	continue;
	375	}
	376
	377	idx = find_next_zero(pool->bitmap[i], last_idx);
	378	if (!blocks_free(pool, i, idx, nr_blocks)) {
	379	idx += nr_blocks;
	380	if (idx < SMALLOC_BPI)
	381	last_idx = idx;
	382	else {
	383	last_idx = 0;
	384	while (idx >= SMALLOC_BPI) {
	385	i++;
	386	idx -= SMALLOC_BPI;
	387	}
	388	}
	389	continue;
	390	}
	391	set_blocks(pool, i, idx, nr_blocks);
	392	offset = i * SMALLOC_BPL + idx * SMALLOC_BPB;
	393	break;
	394	}
	395
	396	if (i < pool->nr_blocks) {
	397	pool->free_blocks -= nr_blocks;
	398	ret = pool->map + offset;
	399	}
	400	fail:
	401	pool_unlock(pool);
	402	return ret;
	403	}
	404
	405	static void smalloc_pool(struct pool pool, unsigned int size)
	406	{
	407	unsigned int alloc_size = size + sizeof(struct block_hdr);
	408	void *ptr;
	409
	410	/*
	411	* Round to int alignment, so that the postred pointer will
	412	* be naturally aligned as well.
	413	*/
	414	#ifdef SMALLOC_REDZONE
	415	alloc_size += sizeof(unsigned int);
	416	alloc_size = (alloc_size + int_mask) & ~int_mask;
	417	#endif
	418
	419	ptr = __smalloc_pool(pool, alloc_size);
	420	if (ptr) {
	421	struct block_hdr *hdr = ptr;
	422
	423	hdr->size = alloc_size;
	424	fill_redzone(hdr);
	425
	426	ptr += sizeof(*hdr);
	427	memset(ptr, 0, size);
	428	}
	429
	430	return ptr;
	431	}
	432
	433	void *smalloc(unsigned int size)
	434	{
	435	unsigned int i;
	436
	437	global_write_lock();
	438	i = last_pool;
	439
	440	do {
	441	for (; i < nr_pools; i++) {
	442	void *ptr = smalloc_pool(&mp[i], size);
	443
	444	if (ptr) {
	445	last_pool = i;
	446	global_write_unlock();
	447	return ptr;
	448	}
	449	}
	450	if (last_pool) {
	451	last_pool = 0;
	452	continue;
	453	}
	454
	455	if (nr_pools + 1 > MAX_POOLS)
	456	break;
	457	else {
	458	i = nr_pools;
	459	if (add_pool(&mp[nr_pools], size))
	460	goto out;
	461	}
	462	} while (1);
	463
	464	out:
	465	global_write_unlock();
	466	return NULL;
	467	}
	468
	469	char smalloc_strdup(const char str)
	470	{
	471	char *ptr;
	472
	473	ptr = smalloc(strlen(str) + 1);
	474	strcpy(ptr, str);
	475	return ptr;
	476	}