[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>
#ifdef CONFIG_VALGRIND_DEV
#include <valgrind/valgrind.h>
#else
#define RUNNING_ON_VALGRIND 0
#define VALGRIND_MALLOCLIKE_BLOCK(addr, size, rzB, is_zeroed) do { } while (0)
#define VALGRIND_FREELIKE_BLOCK(addr, rzB) do { } while (0)
#endif

#include "fio.h"
#include "fio_sem.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_sem *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;
};

#ifdef SMALLOC_REDZONE
#define REDZONE_SIZE sizeof(unsigned int)
#else
#define REDZONE_SIZE 0
#endif

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

	pool->lock = fio_sem_init(FIO_SEM_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_sem_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 = (uintptr_t) PTR_ALIGN(ptr, int_mask);

	return (void *) ptr;
}

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

	/* Let Valgrind fill the red zones. */
	if (RUNNING_ON_VALGRIND)
		return;

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

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

	/* Let Valgrind check the red zones. */
	if (RUNNING_ON_VALGRIND)
		return;

	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_sem_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_sem_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) {
		VALGRIND_FREELIKE_BLOCK(ptr, REDZONE_SIZE);
		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_sem_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_sem_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;
}

static void *__smalloc(size_t size, bool is_zeroed)
{
	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;
				VALGRIND_MALLOCLIKE_BLOCK(ptr, size,
							  REDZONE_SIZE,
							  is_zeroed);
				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 *smalloc(size_t size)
{
	return __smalloc(size, false);
}

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

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	#ifdef CONFIG_VALGRIND_DEV
	16	#include <valgrind/valgrind.h>
	17	#else
	18	#define RUNNING_ON_VALGRIND 0
	19	#define VALGRIND_MALLOCLIKE_BLOCK(addr, size, rzB, is_zeroed) do { } while (0)
	20	#define VALGRIND_FREELIKE_BLOCK(addr, rzB) do { } while (0)
	21	#endif
	22
	23	#include "fio.h"
	24	#include "fio_sem.h"
	25	#include "arch/arch.h"
	26	#include "os/os.h"
	27	#include "smalloc.h"
	28	#include "log.h"
	29
	30	#define SMALLOC_REDZONE /* define to detect memory corruption */
	31
	32	#define SMALLOC_BPB 32 /* block size, bytes-per-bit in bitmap */
	33	#define SMALLOC_BPI (sizeof(unsigned int) * 8)
	34	#define SMALLOC_BPL (SMALLOC_BPB * SMALLOC_BPI)
	35
	36	#define INITIAL_SIZE 1610241024 /* new pool size */
	37	#define INITIAL_POOLS 8 /* maximum number of pools to setup */
	38
	39	#define MAX_POOLS 16
	40
	41	#define SMALLOC_PRE_RED 0xdeadbeefU
	42	#define SMALLOC_POST_RED 0x5aa55aa5U
	43
	44	unsigned int smalloc_pool_size = INITIAL_SIZE;
	45	#ifdef SMALLOC_REDZONE
	46	static const int int_mask = sizeof(int) - 1;
	47	#endif
	48
	49	struct pool {
	50	struct fio_sem lock; / protects this pool */
	51	void map; / map of blocks */
	52	unsigned int bitmap; / blocks free/busy map */
	53	size_t free_blocks; /* free blocks */
	54	size_t nr_blocks; /* total blocks */
	55	size_t next_non_full;
	56	size_t mmap_size;
	57	};
	58
	59	#ifdef SMALLOC_REDZONE
	60	#define REDZONE_SIZE sizeof(unsigned int)
	61	#else
	62	#define REDZONE_SIZE 0
	63	#endif
	64
	65	struct block_hdr {
	66	size_t size;
	67	#ifdef SMALLOC_REDZONE
	68	unsigned int prered;
	69	#endif
	70	};
	71
	72	static struct pool mp[MAX_POOLS];
	73	static unsigned int nr_pools;
	74	static unsigned int last_pool;
	75
	76	static inline int ptr_valid(struct pool pool, void ptr)
	77	{
	78	unsigned int pool_size = pool->nr_blocks * SMALLOC_BPL;
	79
	80	return (ptr >= pool->map) && (ptr < pool->map + pool_size);
	81	}
	82
	83	static inline size_t size_to_blocks(size_t size)
	84	{
	85	return (size + SMALLOC_BPB - 1) / SMALLOC_BPB;
	86	}
	87
	88	static int blocks_iter(struct pool *pool, unsigned int pool_idx,
	89	unsigned int idx, size_t nr_blocks,
	90	int (func)(unsigned int map, unsigned int mask))
	91	{
	92
	93	while (nr_blocks) {
	94	unsigned int this_blocks, mask;
	95	unsigned int *map;
	96
	97	if (pool_idx >= pool->nr_blocks)
	98	return 0;
	99
	100	map = &pool->bitmap[pool_idx];
	101
	102	this_blocks = nr_blocks;
	103	if (this_blocks + idx > SMALLOC_BPI) {
	104	this_blocks = SMALLOC_BPI - idx;
	105	idx = SMALLOC_BPI - this_blocks;
	106	}
	107
	108	if (this_blocks == SMALLOC_BPI)
	109	mask = -1U;
	110	else
	111	mask = ((1U << this_blocks) - 1) << idx;
	112
	113	if (!func(map, mask))
	114	return 0;
	115
	116	nr_blocks -= this_blocks;
	117	idx = 0;
	118	pool_idx++;
	119	}
	120
	121	return 1;
	122	}
	123
	124	static int mask_cmp(unsigned int *map, unsigned int mask)
	125	{
	126	return !(*map & mask);
	127	}
	128
	129	static int mask_clear(unsigned int *map, unsigned int mask)
	130	{
	131	assert((*map & mask) == mask);
	132	*map &= ~mask;
	133	return 1;
	134	}
	135
	136	static int mask_set(unsigned int *map, unsigned int mask)
	137	{
	138	assert(!(*map & mask));
	139	*map \|= mask;
	140	return 1;
	141	}
	142
	143	static int blocks_free(struct pool *pool, unsigned int pool_idx,
	144	unsigned int idx, size_t nr_blocks)
	145	{
	146	return blocks_iter(pool, pool_idx, idx, nr_blocks, mask_cmp);
	147	}
	148
	149	static void set_blocks(struct pool *pool, unsigned int pool_idx,
	150	unsigned int idx, size_t nr_blocks)
	151	{
	152	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_set);
	153	}
	154
	155	static void clear_blocks(struct pool *pool, unsigned int pool_idx,
	156	unsigned int idx, size_t nr_blocks)
	157	{
	158	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_clear);
	159	}
	160
	161	static int find_next_zero(int word, int start)
	162	{
	163	assert(word != -1U);
	164	word >>= start;
	165	return ffz(word) + start;
	166	}
	167
	168	static bool add_pool(struct pool *pool, unsigned int alloc_size)
	169	{
	170	int bitmap_blocks;
	171	int mmap_flags;
	172	void *ptr;
	173
	174	if (nr_pools == MAX_POOLS)
	175	return false;
	176
	177	#ifdef SMALLOC_REDZONE
	178	alloc_size += sizeof(unsigned int);
	179	#endif
	180	alloc_size += sizeof(struct block_hdr);
	181	if (alloc_size < INITIAL_SIZE)
	182	alloc_size = INITIAL_SIZE;
	183
	184	/* round up to nearest full number of blocks */
	185	alloc_size = (alloc_size + SMALLOC_BPL - 1) & ~(SMALLOC_BPL - 1);
	186	bitmap_blocks = alloc_size / SMALLOC_BPL;
	187	alloc_size += bitmap_blocks * sizeof(unsigned int);
	188	pool->mmap_size = alloc_size;
	189
	190	pool->nr_blocks = bitmap_blocks;
	191	pool->free_blocks = bitmap_blocks * SMALLOC_BPB;
	192
	193	mmap_flags = OS_MAP_ANON;
	194	#ifdef CONFIG_ESX
	195	mmap_flags \|= MAP_PRIVATE;
	196	#else
	197	mmap_flags \|= MAP_SHARED;
	198	#endif
	199	ptr = mmap(NULL, alloc_size, PROT_READ\|PROT_WRITE, mmap_flags, -1, 0);
	200
	201	if (ptr == MAP_FAILED)
	202	goto out_fail;
	203
	204	pool->map = ptr;
	205	pool->bitmap = (unsigned int )((char ) ptr + (pool->nr_blocks * SMALLOC_BPL));
	206	memset(pool->bitmap, 0, bitmap_blocks * sizeof(unsigned int));
	207
	208	pool->lock = fio_sem_init(FIO_SEM_UNLOCKED);
	209	if (!pool->lock)
	210	goto out_fail;
	211
	212	nr_pools++;
	213	return true;
	214	out_fail:
	215	log_err("smalloc: failed adding pool\n");
	216	if (pool->map)
	217	munmap(pool->map, pool->mmap_size);
	218	return false;
	219	}
	220
	221	void sinit(void)
	222	{
	223	bool ret;
	224	int i;
	225
	226	for (i = 0; i < INITIAL_POOLS; i++) {
	227	ret = add_pool(&mp[nr_pools], smalloc_pool_size);
	228	if (!ret)
	229	break;
	230	}
	231
	232	/*
	233	* If we added at least one pool, we should be OK for most
	234	* cases.
	235	*/
	236	assert(i);
	237	}
	238
	239	static void cleanup_pool(struct pool *pool)
	240	{
	241	/*
	242	* This will also remove the temporary file we used as a backing
	243	* store, it was already unlinked
	244	*/
	245	munmap(pool->map, pool->mmap_size);
	246
	247	if (pool->lock)
	248	fio_sem_remove(pool->lock);
	249	}
	250
	251	void scleanup(void)
	252	{
	253	unsigned int i;
	254
	255	for (i = 0; i < nr_pools; i++)
	256	cleanup_pool(&mp[i]);
	257	}
	258
	259	#ifdef SMALLOC_REDZONE
	260	static void postred_ptr(struct block_hdr hdr)
	261	{
	262	uintptr_t ptr;
	263
	264	ptr = (uintptr_t) hdr + hdr->size - sizeof(unsigned int);
	265	ptr = (uintptr_t) PTR_ALIGN(ptr, int_mask);
	266
	267	return (void *) ptr;
	268	}
	269
	270	static void fill_redzone(struct block_hdr *hdr)
	271	{
	272	unsigned int *postred = postred_ptr(hdr);
	273
	274	/* Let Valgrind fill the red zones. */
	275	if (RUNNING_ON_VALGRIND)
	276	return;
	277
	278	hdr->prered = SMALLOC_PRE_RED;
	279	*postred = SMALLOC_POST_RED;
	280	}
	281
	282	static void sfree_check_redzone(struct block_hdr *hdr)
	283	{
	284	unsigned int *postred = postred_ptr(hdr);
	285
	286	/* Let Valgrind check the red zones. */
	287	if (RUNNING_ON_VALGRIND)
	288	return;
	289
	290	if (hdr->prered != SMALLOC_PRE_RED) {
	291	log_err("smalloc pre redzone destroyed!\n"
	292	" ptr=%p, prered=%x, expected %x\n",
	293	hdr, hdr->prered, SMALLOC_PRE_RED);
	294	assert(0);
	295	}
	296	if (*postred != SMALLOC_POST_RED) {
	297	log_err("smalloc post redzone destroyed!\n"
	298	" ptr=%p, postred=%x, expected %x\n",
	299	hdr, *postred, SMALLOC_POST_RED);
	300	assert(0);
	301	}
	302	}
	303	#else
	304	static void fill_redzone(struct block_hdr *hdr)
	305	{
	306	}
	307
	308	static void sfree_check_redzone(struct block_hdr *hdr)
	309	{
	310	}
	311	#endif
	312
	313	static void sfree_pool(struct pool pool, void ptr)
	314	{
	315	struct block_hdr *hdr;
	316	unsigned int i, idx;
	317	unsigned long offset;
	318
	319	if (!ptr)
	320	return;
	321
	322	ptr -= sizeof(*hdr);
	323	hdr = ptr;
	324
	325	assert(ptr_valid(pool, ptr));
	326
	327	sfree_check_redzone(hdr);
	328
	329	offset = ptr - pool->map;
	330	i = offset / SMALLOC_BPL;
	331	idx = (offset % SMALLOC_BPL) / SMALLOC_BPB;
	332
	333	fio_sem_down(pool->lock);
	334	clear_blocks(pool, i, idx, size_to_blocks(hdr->size));
	335	if (i < pool->next_non_full)
	336	pool->next_non_full = i;
	337	pool->free_blocks += size_to_blocks(hdr->size);
	338	fio_sem_up(pool->lock);
	339	}
	340
	341	void sfree(void *ptr)
	342	{
	343	struct pool *pool = NULL;
	344	unsigned int i;
	345
	346	if (!ptr)
	347	return;
	348
	349	for (i = 0; i < nr_pools; i++) {
	350	if (ptr_valid(&mp[i], ptr)) {
	351	pool = &mp[i];
	352	break;
	353	}
	354	}
	355
	356	if (pool) {
	357	VALGRIND_FREELIKE_BLOCK(ptr, REDZONE_SIZE);
	358	sfree_pool(pool, ptr);
	359	return;
	360	}
	361
	362	log_err("smalloc: ptr %p not from smalloc pool\n", ptr);
	363	}
	364
	365	static void __smalloc_pool(struct pool pool, size_t size)
	366	{
	367	size_t nr_blocks;
	368	unsigned int i;
	369	unsigned int offset;
	370	unsigned int last_idx;
	371	void *ret = NULL;
	372
	373	fio_sem_down(pool->lock);
	374
	375	nr_blocks = size_to_blocks(size);
	376	if (nr_blocks > pool->free_blocks)
	377	goto fail;
	378
	379	i = pool->next_non_full;
	380	last_idx = 0;
	381	offset = -1U;
	382	while (i < pool->nr_blocks) {
	383	unsigned int idx;
	384
	385	if (pool->bitmap[i] == -1U) {
	386	i++;
	387	pool->next_non_full = i;
	388	last_idx = 0;
	389	continue;
	390	}
	391
	392	idx = find_next_zero(pool->bitmap[i], last_idx);
	393	if (!blocks_free(pool, i, idx, nr_blocks)) {
	394	idx += nr_blocks;
	395	if (idx < SMALLOC_BPI)
	396	last_idx = idx;
	397	else {
	398	last_idx = 0;
	399	while (idx >= SMALLOC_BPI) {
	400	i++;
	401	idx -= SMALLOC_BPI;
	402	}
	403	}
	404	continue;
	405	}
	406	set_blocks(pool, i, idx, nr_blocks);
	407	offset = i * SMALLOC_BPL + idx * SMALLOC_BPB;
	408	break;
	409	}
	410
	411	if (i < pool->nr_blocks) {
	412	pool->free_blocks -= nr_blocks;
	413	ret = pool->map + offset;
	414	}
	415	fail:
	416	fio_sem_up(pool->lock);
	417	return ret;
	418	}
	419
	420	static void smalloc_pool(struct pool pool, size_t size)
	421	{
	422	size_t alloc_size = size + sizeof(struct block_hdr);
	423	void *ptr;
	424
	425	/*
	426	* Round to int alignment, so that the postred pointer will
	427	* be naturally aligned as well.
	428	*/
	429	#ifdef SMALLOC_REDZONE
	430	alloc_size += sizeof(unsigned int);
	431	alloc_size = (alloc_size + int_mask) & ~int_mask;
	432	#endif
	433
	434	ptr = __smalloc_pool(pool, alloc_size);
	435	if (ptr) {
	436	struct block_hdr *hdr = ptr;
	437
	438	hdr->size = alloc_size;
	439	fill_redzone(hdr);
	440
	441	ptr += sizeof(*hdr);
	442	memset(ptr, 0, size);
	443	}
	444
	445	return ptr;
	446	}
	447
	448	static void *__smalloc(size_t size, bool is_zeroed)
	449	{
	450	unsigned int i, end_pool;
	451
	452	if (size != (unsigned int) size)
	453	return NULL;
	454
	455	i = last_pool;
	456	end_pool = nr_pools;
	457
	458	do {
	459	for (; i < end_pool; i++) {
	460	void *ptr = smalloc_pool(&mp[i], size);
	461
	462	if (ptr) {
	463	last_pool = i;
	464	VALGRIND_MALLOCLIKE_BLOCK(ptr, size,
	465	REDZONE_SIZE,
	466	is_zeroed);
	467	return ptr;
	468	}
	469	}
	470	if (last_pool) {
	471	end_pool = last_pool;
	472	last_pool = i = 0;
	473	continue;
	474	}
	475
	476	break;
	477	} while (1);
	478
	479	log_err("smalloc: OOM. Consider using --alloc-size to increase the "
	480	"shared memory available.\n");
	481	return NULL;
	482	}
	483
	484	void *smalloc(size_t size)
	485	{
	486	return __smalloc(size, false);
	487	}
	488
	489	void *scalloc(size_t nmemb, size_t size)
	490	{
	491	return __smalloc(nmemb * size, true);
	492	}
	493
	494	char smalloc_strdup(const char str)
	495	{
	496	char *ptr = NULL;
	497
	498	ptr = smalloc(strlen(str) + 1);
	499	if (ptr)
	500	strcpy(ptr, str);
	501	return ptr;
	502	}