[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 <inttypes.h>
#include <sys/types.h>
#include <limits.h>
#include <fcntl.h>

#include "mutex.h"
#include "arch/arch.h"
#include "os/os.h"
#include "smalloc.h"
#include "log.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	16*1024*1024	/* new pool size */
#define INITIAL_POOLS	8		/* maximum number of pools to setup */

#define MAX_POOLS	16

#define SMALLOC_PRE_RED		0xdeadbeefU
#define SMALLOC_POST_RED	0x5aa55aa5U

unsigned int smalloc_pool_size = INITIAL_SIZE;
#ifdef SMALLOC_REDZONE
static const int int_mask = sizeof(int) - 1;
#endif

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

struct block_hdr {
	size_t 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 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 size_t size_to_blocks(size_t size)
{
	return (size + SMALLOC_BPB - 1) / SMALLOC_BPB;
}

static int blocks_iter(struct pool *pool, unsigned int pool_idx,
		       unsigned int idx, size_t 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, size_t 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, size_t 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, size_t 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 bool add_pool(struct pool *pool, unsigned int alloc_size)
{
	int bitmap_blocks;
	int mmap_flags;
	void *ptr;

	if (nr_pools == MAX_POOLS)
		return false;

#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;

	mmap_flags = OS_MAP_ANON;
#ifdef CONFIG_ESX
	mmap_flags |= MAP_PRIVATE;
#else
	mmap_flags |= MAP_SHARED;
#endif
	ptr = mmap(NULL, alloc_size, PROT_READ|PROT_WRITE, mmap_flags, -1, 0);

	if (ptr == MAP_FAILED)
		goto out_fail;

	pool->map = ptr;
	pool->bitmap = (void *) ptr + (pool->nr_blocks * SMALLOC_BPL);
	memset(pool->bitmap, 0, bitmap_blocks * sizeof(unsigned int));

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

	nr_pools++;
	return true;
out_fail:
	log_err("smalloc: failed adding pool\n");
	if (pool->map)
		munmap(pool->map, pool->mmap_size);
	return false;
}

void sinit(void)
{
	bool ret;
	int i;

	for (i = 0; i < INITIAL_POOLS; i++) {
		ret = add_pool(&mp[nr_pools], smalloc_pool_size);
		if (!ret)
			break;
	}

	/*
	 * If we added at least one pool, we should be OK for most
	 * cases.
	 */
	assert(i);
}

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]);
}

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

	ptr = (uintptr_t) 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) {
		log_err("smalloc pre redzone destroyed!\n"
			" ptr=%p, prered=%x, expected %x\n",
				hdr, hdr->prered, SMALLOC_PRE_RED);
		assert(0);
	}
	if (*postred != SMALLOC_POST_RED) {
		log_err("smalloc post redzone destroyed!\n"
			"  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;

	fio_mutex_down(pool->lock);
	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);
	fio_mutex_up(pool->lock);
}

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

	if (!ptr)
		return;

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

	if (pool) {
		sfree_pool(pool, ptr);
		return;
	}

	log_err("smalloc: ptr %p not from smalloc pool\n", ptr);
}

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

	fio_mutex_down(pool->lock);

	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:
	fio_mutex_up(pool->lock);
	return ret;
}

static void *smalloc_pool(struct pool *pool, size_t size)
{
	size_t 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(size_t size)
{
	unsigned int i, end_pool;

	if (size != (unsigned int) size)
		return NULL;

	i = last_pool;
	end_pool = nr_pools;

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

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

		break;
	} while (1);

	log_err("smalloc: OOM. Consider using --alloc-size to increase the "
		"shared memory available.\n");
	return NULL;
}

void *scalloc(size_t nmemb, size_t size)
{
	return smalloc(nmemb * size);
}

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

	ptr = smalloc(strlen(str) + 1);
	if (ptr)
		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 <inttypes.h>
	12	#include <sys/types.h>
	13	#include <limits.h>
	14	#include <fcntl.h>
	15
	16	#include "mutex.h"
	17	#include "arch/arch.h"
	18	#include "os/os.h"
	19	#include "smalloc.h"
	20	#include "log.h"
	21
	22	#define SMALLOC_REDZONE /* define to detect memory corruption */
	23
	24	#define SMALLOC_BPB 32 /* block size, bytes-per-bit in bitmap */
	25	#define SMALLOC_BPI (sizeof(unsigned int) * 8)
	26	#define SMALLOC_BPL (SMALLOC_BPB * SMALLOC_BPI)
	27
	28	#define INITIAL_SIZE 1610241024 /* new pool size */
	29	#define INITIAL_POOLS 8 /* maximum number of pools to setup */
	30
	31	#define MAX_POOLS 16
	32
	33	#define SMALLOC_PRE_RED 0xdeadbeefU
	34	#define SMALLOC_POST_RED 0x5aa55aa5U
	35
	36	unsigned int smalloc_pool_size = INITIAL_SIZE;
	37	#ifdef SMALLOC_REDZONE
	38	static const int int_mask = sizeof(int) - 1;
	39	#endif
	40
	41	struct pool {
	42	struct fio_mutex lock; / protects this pool */
	43	void map; / map of blocks */
	44	unsigned int bitmap; / blocks free/busy map */
	45	size_t free_blocks; /* free blocks */
	46	size_t nr_blocks; /* total blocks */
	47	size_t next_non_full;
	48	size_t mmap_size;
	49	};
	50
	51	struct block_hdr {
	52	size_t size;
	53	#ifdef SMALLOC_REDZONE
	54	unsigned int prered;
	55	#endif
	56	};
	57
	58	static struct pool mp[MAX_POOLS];
	59	static unsigned int nr_pools;
	60	static unsigned int last_pool;
	61
	62	static inline int ptr_valid(struct pool pool, void ptr)
	63	{
	64	unsigned int pool_size = pool->nr_blocks * SMALLOC_BPL;
	65
	66	return (ptr >= pool->map) && (ptr < pool->map + pool_size);
	67	}
	68
	69	static inline size_t size_to_blocks(size_t size)
	70	{
	71	return (size + SMALLOC_BPB - 1) / SMALLOC_BPB;
	72	}
	73
	74	static int blocks_iter(struct pool *pool, unsigned int pool_idx,
	75	unsigned int idx, size_t nr_blocks,
	76	int (func)(unsigned int map, unsigned int mask))
	77	{
	78
	79	while (nr_blocks) {
	80	unsigned int this_blocks, mask;
	81	unsigned int *map;
	82
	83	if (pool_idx >= pool->nr_blocks)
	84	return 0;
	85
	86	map = &pool->bitmap[pool_idx];
	87
	88	this_blocks = nr_blocks;
	89	if (this_blocks + idx > SMALLOC_BPI) {
	90	this_blocks = SMALLOC_BPI - idx;
	91	idx = SMALLOC_BPI - this_blocks;
	92	}
	93
	94	if (this_blocks == SMALLOC_BPI)
	95	mask = -1U;
	96	else
	97	mask = ((1U << this_blocks) - 1) << idx;
	98
	99	if (!func(map, mask))
	100	return 0;
	101
	102	nr_blocks -= this_blocks;
	103	idx = 0;
	104	pool_idx++;
	105	}
	106
	107	return 1;
	108	}
	109
	110	static int mask_cmp(unsigned int *map, unsigned int mask)
	111	{
	112	return !(*map & mask);
	113	}
	114
	115	static int mask_clear(unsigned int *map, unsigned int mask)
	116	{
	117	assert((*map & mask) == mask);
	118	*map &= ~mask;
	119	return 1;
	120	}
	121
	122	static int mask_set(unsigned int *map, unsigned int mask)
	123	{
	124	assert(!(*map & mask));
	125	*map \|= mask;
	126	return 1;
	127	}
	128
	129	static int blocks_free(struct pool *pool, unsigned int pool_idx,
	130	unsigned int idx, size_t nr_blocks)
	131	{
	132	return blocks_iter(pool, pool_idx, idx, nr_blocks, mask_cmp);
	133	}
	134
	135	static void set_blocks(struct pool *pool, unsigned int pool_idx,
	136	unsigned int idx, size_t nr_blocks)
	137	{
	138	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_set);
	139	}
	140
	141	static void clear_blocks(struct pool *pool, unsigned int pool_idx,
	142	unsigned int idx, size_t nr_blocks)
	143	{
	144	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_clear);
	145	}
	146
	147	static int find_next_zero(int word, int start)
	148	{
	149	assert(word != -1U);
	150	word >>= start;
	151	return ffz(word) + start;
	152	}
	153
	154	static bool add_pool(struct pool *pool, unsigned int alloc_size)
	155	{
	156	int bitmap_blocks;
	157	int mmap_flags;
	158	void *ptr;
	159
	160	if (nr_pools == MAX_POOLS)
	161	return false;
	162
	163	#ifdef SMALLOC_REDZONE
	164	alloc_size += sizeof(unsigned int);
	165	#endif
	166	alloc_size += sizeof(struct block_hdr);
	167	if (alloc_size < INITIAL_SIZE)
	168	alloc_size = INITIAL_SIZE;
	169
	170	/* round up to nearest full number of blocks */
	171	alloc_size = (alloc_size + SMALLOC_BPL - 1) & ~(SMALLOC_BPL - 1);
	172	bitmap_blocks = alloc_size / SMALLOC_BPL;
	173	alloc_size += bitmap_blocks * sizeof(unsigned int);
	174	pool->mmap_size = alloc_size;
	175
	176	pool->nr_blocks = bitmap_blocks;
	177	pool->free_blocks = bitmap_blocks * SMALLOC_BPB;
	178
	179	mmap_flags = OS_MAP_ANON;
	180	#ifdef CONFIG_ESX
	181	mmap_flags \|= MAP_PRIVATE;
	182	#else
	183	mmap_flags \|= MAP_SHARED;
	184	#endif
	185	ptr = mmap(NULL, alloc_size, PROT_READ\|PROT_WRITE, mmap_flags, -1, 0);
	186
	187	if (ptr == MAP_FAILED)
	188	goto out_fail;
	189
	190	pool->map = ptr;
	191	pool->bitmap = (void ) ptr + (pool->nr_blocks SMALLOC_BPL);
	192	memset(pool->bitmap, 0, bitmap_blocks * sizeof(unsigned int));
	193
	194	pool->lock = fio_mutex_init(FIO_MUTEX_UNLOCKED);
	195	if (!pool->lock)
	196	goto out_fail;
	197
	198	nr_pools++;
	199	return true;
	200	out_fail:
	201	log_err("smalloc: failed adding pool\n");
	202	if (pool->map)
	203	munmap(pool->map, pool->mmap_size);
	204	return false;
	205	}
	206
	207	void sinit(void)
	208	{
	209	bool ret;
	210	int i;
	211
	212	for (i = 0; i < INITIAL_POOLS; i++) {
	213	ret = add_pool(&mp[nr_pools], smalloc_pool_size);
	214	if (!ret)
	215	break;
	216	}
	217
	218	/*
	219	* If we added at least one pool, we should be OK for most
	220	* cases.
	221	*/
	222	assert(i);
	223	}
	224
	225	static void cleanup_pool(struct pool *pool)
	226	{
	227	/*
	228	* This will also remove the temporary file we used as a backing
	229	* store, it was already unlinked
	230	*/
	231	munmap(pool->map, pool->mmap_size);
	232
	233	if (pool->lock)
	234	fio_mutex_remove(pool->lock);
	235	}
	236
	237	void scleanup(void)
	238	{
	239	unsigned int i;
	240
	241	for (i = 0; i < nr_pools; i++)
	242	cleanup_pool(&mp[i]);
	243	}
	244
	245	#ifdef SMALLOC_REDZONE
	246	static void postred_ptr(struct block_hdr hdr)
	247	{
	248	uintptr_t ptr;
	249
	250	ptr = (uintptr_t) hdr + hdr->size - sizeof(unsigned int);
	251	ptr = (ptr + int_mask) & ~int_mask;
	252
	253	return (void *) ptr;
	254	}
	255
	256	static void fill_redzone(struct block_hdr *hdr)
	257	{
	258	unsigned int *postred = postred_ptr(hdr);
	259
	260	hdr->prered = SMALLOC_PRE_RED;
	261	*postred = SMALLOC_POST_RED;
	262	}
	263
	264	static void sfree_check_redzone(struct block_hdr *hdr)
	265	{
	266	unsigned int *postred = postred_ptr(hdr);
	267
	268	if (hdr->prered != SMALLOC_PRE_RED) {
	269	log_err("smalloc pre redzone destroyed!\n"
	270	" ptr=%p, prered=%x, expected %x\n",
	271	hdr, hdr->prered, SMALLOC_PRE_RED);
	272	assert(0);
	273	}
	274	if (*postred != SMALLOC_POST_RED) {
	275	log_err("smalloc post redzone destroyed!\n"
	276	" ptr=%p, postred=%x, expected %x\n",
	277	hdr, *postred, SMALLOC_POST_RED);
	278	assert(0);
	279	}
	280	}
	281	#else
	282	static void fill_redzone(struct block_hdr *hdr)
	283	{
	284	}
	285
	286	static void sfree_check_redzone(struct block_hdr *hdr)
	287	{
	288	}
	289	#endif
	290
	291	static void sfree_pool(struct pool pool, void ptr)
	292	{
	293	struct block_hdr *hdr;
	294	unsigned int i, idx;
	295	unsigned long offset;
	296
	297	if (!ptr)
	298	return;
	299
	300	ptr -= sizeof(*hdr);
	301	hdr = ptr;
	302
	303	assert(ptr_valid(pool, ptr));
	304
	305	sfree_check_redzone(hdr);
	306
	307	offset = ptr - pool->map;
	308	i = offset / SMALLOC_BPL;
	309	idx = (offset % SMALLOC_BPL) / SMALLOC_BPB;
	310
	311	fio_mutex_down(pool->lock);
	312	clear_blocks(pool, i, idx, size_to_blocks(hdr->size));
	313	if (i < pool->next_non_full)
	314	pool->next_non_full = i;
	315	pool->free_blocks += size_to_blocks(hdr->size);
	316	fio_mutex_up(pool->lock);
	317	}
	318
	319	void sfree(void *ptr)
	320	{
	321	struct pool *pool = NULL;
	322	unsigned int i;
	323
	324	if (!ptr)
	325	return;
	326
	327	for (i = 0; i < nr_pools; i++) {
	328	if (ptr_valid(&mp[i], ptr)) {
	329	pool = &mp[i];
	330	break;
	331	}
	332	}
	333
	334	if (pool) {
	335	sfree_pool(pool, ptr);
	336	return;
	337	}
	338
	339	log_err("smalloc: ptr %p not from smalloc pool\n", ptr);
	340	}
	341
	342	static void __smalloc_pool(struct pool pool, size_t size)
	343	{
	344	size_t nr_blocks;
	345	unsigned int i;
	346	unsigned int offset;
	347	unsigned int last_idx;
	348	void *ret = NULL;
	349
	350	fio_mutex_down(pool->lock);
	351
	352	nr_blocks = size_to_blocks(size);
	353	if (nr_blocks > pool->free_blocks)
	354	goto fail;
	355
	356	i = pool->next_non_full;
	357	last_idx = 0;
	358	offset = -1U;
	359	while (i < pool->nr_blocks) {
	360	unsigned int idx;
	361
	362	if (pool->bitmap[i] == -1U) {
	363	i++;
	364	pool->next_non_full = i;
	365	last_idx = 0;
	366	continue;
	367	}
	368
	369	idx = find_next_zero(pool->bitmap[i], last_idx);
	370	if (!blocks_free(pool, i, idx, nr_blocks)) {
	371	idx += nr_blocks;
	372	if (idx < SMALLOC_BPI)
	373	last_idx = idx;
	374	else {
	375	last_idx = 0;
	376	while (idx >= SMALLOC_BPI) {
	377	i++;
	378	idx -= SMALLOC_BPI;
	379	}
	380	}
	381	continue;
	382	}
	383	set_blocks(pool, i, idx, nr_blocks);
	384	offset = i * SMALLOC_BPL + idx * SMALLOC_BPB;
	385	break;
	386	}
	387
	388	if (i < pool->nr_blocks) {
	389	pool->free_blocks -= nr_blocks;
	390	ret = pool->map + offset;
	391	}
	392	fail:
	393	fio_mutex_up(pool->lock);
	394	return ret;
	395	}
	396
	397	static void smalloc_pool(struct pool pool, size_t size)
	398	{
	399	size_t alloc_size = size + sizeof(struct block_hdr);
	400	void *ptr;
	401
	402	/*
	403	* Round to int alignment, so that the postred pointer will
	404	* be naturally aligned as well.
	405	*/
	406	#ifdef SMALLOC_REDZONE
	407	alloc_size += sizeof(unsigned int);
	408	alloc_size = (alloc_size + int_mask) & ~int_mask;
	409	#endif
	410
	411	ptr = __smalloc_pool(pool, alloc_size);
	412	if (ptr) {
	413	struct block_hdr *hdr = ptr;
	414
	415	hdr->size = alloc_size;
	416	fill_redzone(hdr);
	417
	418	ptr += sizeof(*hdr);
	419	memset(ptr, 0, size);
	420	}
	421
	422	return ptr;
	423	}
	424
	425	void *smalloc(size_t size)
	426	{
	427	unsigned int i, end_pool;
	428
	429	if (size != (unsigned int) size)
	430	return NULL;
	431
	432	i = last_pool;
	433	end_pool = nr_pools;
	434
	435	do {
	436	for (; i < end_pool; i++) {
	437	void *ptr = smalloc_pool(&mp[i], size);
	438
	439	if (ptr) {
	440	last_pool = i;
	441	return ptr;
	442	}
	443	}
	444	if (last_pool) {
	445	end_pool = last_pool;
	446	last_pool = i = 0;
	447	continue;
	448	}
	449
	450	break;
	451	} while (1);
	452
	453	log_err("smalloc: OOM. Consider using --alloc-size to increase the "
	454	"shared memory available.\n");
	455	return NULL;
	456	}
	457
	458	void *scalloc(size_t nmemb, size_t size)
	459	{
	460	return smalloc(nmemb * size);
	461	}
	462
	463	char smalloc_strdup(const char str)
	464	{
	465	char *ptr = NULL;
	466
	467	ptr = smalloc(strlen(str) + 1);
	468	if (ptr)
	469	strcpy(ptr, str);
	470	return ptr;
	471	}