[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 <assert.h>
#include <string.h>

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

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

/*
 * This suppresses the voluminous potential bitmap printout when
 * smalloc encounters an OOM error
 */
static const bool enable_smalloc_debug = false;

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);

	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_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) {
		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 size_t size_to_alloc_size(size_t size)
{
	size_t alloc_size = size + sizeof(struct block_hdr);

	/*
	 * 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

	return alloc_size;
}

static void *smalloc_pool(struct pool *pool, size_t size)
{
	size_t alloc_size = size_to_alloc_size(size);
	void *ptr;

	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_print_bitmap(struct pool *pool)
{
	size_t nr_blocks = pool->nr_blocks;
	unsigned int *bitmap = pool->bitmap;
	unsigned int i, j;
	char *buffer;

	if (!enable_smalloc_debug)
		return;

	buffer = malloc(SMALLOC_BPI + 1);
	if (!buffer)
		return;
	buffer[SMALLOC_BPI] = '\0';

	for (i = 0; i < nr_blocks; i++) {
		unsigned int line = bitmap[i];

		/* skip completely full lines */
		if (line == -1U)
			continue;

		for (j = 0; j < SMALLOC_BPI; j++)
			if ((1 << j) & line)
				buffer[SMALLOC_BPI-1-j] = '1';
			else
				buffer[SMALLOC_BPI-1-j] = '0';

		log_err("smalloc: bitmap %5u, %s\n", i, buffer);
	}

	free(buffer);
}

void smalloc_debug(size_t size)
{
	unsigned int i;
	size_t alloc_size = size_to_alloc_size(size);
	size_t alloc_blocks;

	alloc_blocks = size_to_blocks(alloc_size);

	if (size)
		log_err("smalloc: size = %lu, alloc_size = %lu, blocks = %lu\n",
			(unsigned long) size, (unsigned long) alloc_size,
			(unsigned long) alloc_blocks);
	for (i = 0; i < nr_pools; i++) {
		log_err("smalloc: pool %u, free/total blocks %u/%u\n", i,
			(unsigned int) (mp[i].free_blocks),
			(unsigned int) (mp[i].nr_blocks*sizeof(unsigned int)*8));
		if (size && mp[i].free_blocks >= alloc_blocks) {
			void *ptr = smalloc_pool(&mp[i], size);
			if (ptr) {
				sfree(ptr);
				last_pool = i;
				log_err("smalloc: smalloc_pool %u succeeded\n", i);
			} else {
				log_err("smalloc: smalloc_pool %u failed\n", i);
				log_err("smalloc: next_non_full=%u, nr_blocks=%u\n",
					(unsigned int) mp[i].next_non_full, (unsigned int) mp[i].nr_blocks);
				smalloc_print_bitmap(&mp[i]);
			}
		}
	}
}

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");
	smalloc_debug(size);
	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 <assert.h>
	7	#include <string.h>
	8
	9	#include "fio.h"
	10	#include "fio_sem.h"
	11	#include "os/os.h"
	12	#include "smalloc.h"
	13	#include "log.h"
	14
	15	#define SMALLOC_REDZONE /* define to detect memory corruption */
	16
	17	#define SMALLOC_BPB 32 /* block size, bytes-per-bit in bitmap */
	18	#define SMALLOC_BPI (sizeof(unsigned int) * 8)
	19	#define SMALLOC_BPL (SMALLOC_BPB * SMALLOC_BPI)
	20
	21	#define INITIAL_SIZE 1610241024 /* new pool size */
	22	#define INITIAL_POOLS 8 /* maximum number of pools to setup */
	23
	24	#define MAX_POOLS 16
	25
	26	#define SMALLOC_PRE_RED 0xdeadbeefU
	27	#define SMALLOC_POST_RED 0x5aa55aa5U
	28
	29	unsigned int smalloc_pool_size = INITIAL_SIZE;
	30	#ifdef SMALLOC_REDZONE
	31	static const int int_mask = sizeof(int) - 1;
	32	#endif
	33
	34	struct pool {
	35	struct fio_sem lock; / protects this pool */
	36	void map; / map of blocks */
	37	unsigned int bitmap; / blocks free/busy map */
	38	size_t free_blocks; /* free blocks */
	39	size_t nr_blocks; /* total blocks */
	40	size_t next_non_full;
	41	size_t mmap_size;
	42	};
	43
	44	struct block_hdr {
	45	size_t size;
	46	#ifdef SMALLOC_REDZONE
	47	unsigned int prered;
	48	#endif
	49	};
	50
	51	/*
	52	* This suppresses the voluminous potential bitmap printout when
	53	* smalloc encounters an OOM error
	54	*/
	55	static const bool enable_smalloc_debug = false;
	56
	57	static struct pool mp[MAX_POOLS];
	58	static unsigned int nr_pools;
	59	static unsigned int last_pool;
	60
	61	static inline int ptr_valid(struct pool pool, void ptr)
	62	{
	63	unsigned int pool_size = pool->nr_blocks * SMALLOC_BPL;
	64
	65	return (ptr >= pool->map) && (ptr < pool->map + pool_size);
	66	}
	67
	68	static inline size_t size_to_blocks(size_t size)
	69	{
	70	return (size + SMALLOC_BPB - 1) / SMALLOC_BPB;
	71	}
	72
	73	static int blocks_iter(struct pool *pool, unsigned int pool_idx,
	74	unsigned int idx, size_t nr_blocks,
	75	int (func)(unsigned int map, unsigned int mask))
	76	{
	77
	78	while (nr_blocks) {
	79	unsigned int this_blocks, mask;
	80	unsigned int *map;
	81
	82	if (pool_idx >= pool->nr_blocks)
	83	return 0;
	84
	85	map = &pool->bitmap[pool_idx];
	86
	87	this_blocks = nr_blocks;
	88	if (this_blocks + idx > SMALLOC_BPI) {
	89	this_blocks = SMALLOC_BPI - idx;
	90	idx = SMALLOC_BPI - this_blocks;
	91	}
	92
	93	if (this_blocks == SMALLOC_BPI)
	94	mask = -1U;
	95	else
	96	mask = ((1U << this_blocks) - 1) << idx;
	97
	98	if (!func(map, mask))
	99	return 0;
	100
	101	nr_blocks -= this_blocks;
	102	idx = 0;
	103	pool_idx++;
	104	}
	105
	106	return 1;
	107	}
	108
	109	static int mask_cmp(unsigned int *map, unsigned int mask)
	110	{
	111	return !(*map & mask);
	112	}
	113
	114	static int mask_clear(unsigned int *map, unsigned int mask)
	115	{
	116	assert((*map & mask) == mask);
	117	*map &= ~mask;
	118	return 1;
	119	}
	120
	121	static int mask_set(unsigned int *map, unsigned int mask)
	122	{
	123	assert(!(*map & mask));
	124	*map \|= mask;
	125	return 1;
	126	}
	127
	128	static int blocks_free(struct pool *pool, unsigned int pool_idx,
	129	unsigned int idx, size_t nr_blocks)
	130	{
	131	return blocks_iter(pool, pool_idx, idx, nr_blocks, mask_cmp);
	132	}
	133
	134	static void set_blocks(struct pool *pool, unsigned int pool_idx,
	135	unsigned int idx, size_t nr_blocks)
	136	{
	137	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_set);
	138	}
	139
	140	static void clear_blocks(struct pool *pool, unsigned int pool_idx,
	141	unsigned int idx, size_t nr_blocks)
	142	{
	143	blocks_iter(pool, pool_idx, idx, nr_blocks, mask_clear);
	144	}
	145
	146	static int find_next_zero(int word, int start)
	147	{
	148	assert(word != -1U);
	149	word >>= start;
	150	return ffz(word) + start;
	151	}
	152
	153	static bool add_pool(struct pool *pool, unsigned int alloc_size)
	154	{
	155	int bitmap_blocks;
	156	int mmap_flags;
	157	void *ptr;
	158
	159	if (nr_pools == MAX_POOLS)
	160	return false;
	161
	162	#ifdef SMALLOC_REDZONE
	163	alloc_size += sizeof(unsigned int);
	164	#endif
	165	alloc_size += sizeof(struct block_hdr);
	166	if (alloc_size < INITIAL_SIZE)
	167	alloc_size = INITIAL_SIZE;
	168
	169	/* round up to nearest full number of blocks */
	170	alloc_size = (alloc_size + SMALLOC_BPL - 1) & ~(SMALLOC_BPL - 1);
	171	bitmap_blocks = alloc_size / SMALLOC_BPL;
	172	alloc_size += bitmap_blocks * sizeof(unsigned int);
	173	pool->mmap_size = alloc_size;
	174
	175	pool->nr_blocks = bitmap_blocks;
	176	pool->free_blocks = bitmap_blocks * SMALLOC_BPB;
	177
	178	mmap_flags = OS_MAP_ANON;
	179	#ifdef CONFIG_ESX
	180	mmap_flags \|= MAP_PRIVATE;
	181	#else
	182	mmap_flags \|= MAP_SHARED;
	183	#endif
	184	ptr = mmap(NULL, alloc_size, PROT_READ\|PROT_WRITE, mmap_flags, -1, 0);
	185
	186	if (ptr == MAP_FAILED)
	187	goto out_fail;
	188
	189	pool->map = ptr;
	190	pool->bitmap = (unsigned int )((char ) ptr + (pool->nr_blocks * SMALLOC_BPL));
	191	memset(pool->bitmap, 0, bitmap_blocks * sizeof(unsigned int));
	192
	193	pool->lock = fio_sem_init(FIO_SEM_UNLOCKED);
	194	if (!pool->lock)
	195	goto out_fail;
	196
	197	nr_pools++;
	198	return true;
	199	out_fail:
	200	log_err("smalloc: failed adding pool\n");
	201	if (pool->map)
	202	munmap(pool->map, pool->mmap_size);
	203	return false;
	204	}
	205
	206	void sinit(void)
	207	{
	208	bool ret;
	209	int i;
	210
	211	for (i = 0; i < INITIAL_POOLS; i++) {
	212	ret = add_pool(&mp[nr_pools], smalloc_pool_size);
	213	if (!ret)
	214	break;
	215	}
	216
	217	/*
	218	* If we added at least one pool, we should be OK for most
	219	* cases.
	220	*/
	221	assert(i);
	222	}
	223
	224	static void cleanup_pool(struct pool *pool)
	225	{
	226	/*
	227	* This will also remove the temporary file we used as a backing
	228	* store, it was already unlinked
	229	*/
	230	munmap(pool->map, pool->mmap_size);
	231
	232	if (pool->lock)
	233	fio_sem_remove(pool->lock);
	234	}
	235
	236	void scleanup(void)
	237	{
	238	unsigned int i;
	239
	240	for (i = 0; i < nr_pools; i++)
	241	cleanup_pool(&mp[i]);
	242	}
	243
	244	#ifdef SMALLOC_REDZONE
	245	static void postred_ptr(struct block_hdr hdr)
	246	{
	247	uintptr_t ptr;
	248
	249	ptr = (uintptr_t) hdr + hdr->size - sizeof(unsigned int);
	250	ptr = (uintptr_t) PTR_ALIGN(ptr, int_mask);
	251
	252	return (void *) ptr;
	253	}
	254
	255	static void fill_redzone(struct block_hdr *hdr)
	256	{
	257	unsigned int *postred = postred_ptr(hdr);
	258
	259	hdr->prered = SMALLOC_PRE_RED;
	260	*postred = SMALLOC_POST_RED;
	261	}
	262
	263	static void sfree_check_redzone(struct block_hdr *hdr)
	264	{
	265	unsigned int *postred = postred_ptr(hdr);
	266
	267	if (hdr->prered != SMALLOC_PRE_RED) {
	268	log_err("smalloc pre redzone destroyed!\n"
	269	" ptr=%p, prered=%x, expected %x\n",
	270	hdr, hdr->prered, SMALLOC_PRE_RED);
	271	assert(0);
	272	}
	273	if (*postred != SMALLOC_POST_RED) {
	274	log_err("smalloc post redzone destroyed!\n"
	275	" ptr=%p, postred=%x, expected %x\n",
	276	hdr, *postred, SMALLOC_POST_RED);
	277	assert(0);
	278	}
	279	}
	280	#else
	281	static void fill_redzone(struct block_hdr *hdr)
	282	{
	283	}
	284
	285	static void sfree_check_redzone(struct block_hdr *hdr)
	286	{
	287	}
	288	#endif
	289
	290	static void sfree_pool(struct pool pool, void ptr)
	291	{
	292	struct block_hdr *hdr;
	293	unsigned int i, idx;
	294	unsigned long offset;
	295
	296	if (!ptr)
	297	return;
	298
	299	ptr -= sizeof(*hdr);
	300	hdr = ptr;
	301
	302	assert(ptr_valid(pool, ptr));
	303
	304	sfree_check_redzone(hdr);
	305
	306	offset = ptr - pool->map;
	307	i = offset / SMALLOC_BPL;
	308	idx = (offset % SMALLOC_BPL) / SMALLOC_BPB;
	309
	310	fio_sem_down(pool->lock);
	311	clear_blocks(pool, i, idx, size_to_blocks(hdr->size));
	312	if (i < pool->next_non_full)
	313	pool->next_non_full = i;
	314	pool->free_blocks += size_to_blocks(hdr->size);
	315	fio_sem_up(pool->lock);
	316	}
	317
	318	void sfree(void *ptr)
	319	{
	320	struct pool *pool = NULL;
	321	unsigned int i;
	322
	323	if (!ptr)
	324	return;
	325
	326	for (i = 0; i < nr_pools; i++) {
	327	if (ptr_valid(&mp[i], ptr)) {
	328	pool = &mp[i];
	329	break;
	330	}
	331	}
	332
	333	if (pool) {
	334	sfree_pool(pool, ptr);
	335	return;
	336	}
	337
	338	log_err("smalloc: ptr %p not from smalloc pool\n", ptr);
	339	}
	340
	341	static void __smalloc_pool(struct pool pool, size_t size)
	342	{
	343	size_t nr_blocks;
	344	unsigned int i;
	345	unsigned int offset;
	346	unsigned int last_idx;
	347	void *ret = NULL;
	348
	349	fio_sem_down(pool->lock);
	350
	351	nr_blocks = size_to_blocks(size);
	352	if (nr_blocks > pool->free_blocks)
	353	goto fail;
	354
	355	i = pool->next_non_full;
	356	last_idx = 0;
	357	offset = -1U;
	358	while (i < pool->nr_blocks) {
	359	unsigned int idx;
	360
	361	if (pool->bitmap[i] == -1U) {
	362	i++;
	363	pool->next_non_full = i;
	364	last_idx = 0;
	365	continue;
	366	}
	367
	368	idx = find_next_zero(pool->bitmap[i], last_idx);
	369	if (!blocks_free(pool, i, idx, nr_blocks)) {
	370	idx += nr_blocks;
	371	if (idx < SMALLOC_BPI)
	372	last_idx = idx;
	373	else {
	374	last_idx = 0;
	375	while (idx >= SMALLOC_BPI) {
	376	i++;
	377	idx -= SMALLOC_BPI;
	378	}
	379	}
	380	continue;
	381	}
	382	set_blocks(pool, i, idx, nr_blocks);
	383	offset = i * SMALLOC_BPL + idx * SMALLOC_BPB;
	384	break;
	385	}
	386
	387	if (i < pool->nr_blocks) {
	388	pool->free_blocks -= nr_blocks;
	389	ret = pool->map + offset;
	390	}
	391	fail:
	392	fio_sem_up(pool->lock);
	393	return ret;
	394	}
	395
	396	static size_t size_to_alloc_size(size_t size)
	397	{
	398	size_t alloc_size = size + sizeof(struct block_hdr);
	399
	400	/*
	401	* Round to int alignment, so that the postred pointer will
	402	* be naturally aligned as well.
	403	*/
	404	#ifdef SMALLOC_REDZONE
	405	alloc_size += sizeof(unsigned int);
	406	alloc_size = (alloc_size + int_mask) & ~int_mask;
	407	#endif
	408
	409	return alloc_size;
	410	}
	411
	412	static void smalloc_pool(struct pool pool, size_t size)
	413	{
	414	size_t alloc_size = size_to_alloc_size(size);
	415	void *ptr;
	416
	417	ptr = __smalloc_pool(pool, alloc_size);
	418	if (ptr) {
	419	struct block_hdr *hdr = ptr;
	420
	421	hdr->size = alloc_size;
	422	fill_redzone(hdr);
	423
	424	ptr += sizeof(*hdr);
	425	memset(ptr, 0, size);
	426	}
	427
	428	return ptr;
	429	}
	430
	431	static void smalloc_print_bitmap(struct pool *pool)
	432	{
	433	size_t nr_blocks = pool->nr_blocks;
	434	unsigned int *bitmap = pool->bitmap;
	435	unsigned int i, j;
	436	char *buffer;
	437
	438	if (!enable_smalloc_debug)
	439	return;
	440
	441	buffer = malloc(SMALLOC_BPI + 1);
	442	if (!buffer)
	443	return;
	444	buffer[SMALLOC_BPI] = '\0';
	445
	446	for (i = 0; i < nr_blocks; i++) {
	447	unsigned int line = bitmap[i];
	448
	449	/* skip completely full lines */
	450	if (line == -1U)
	451	continue;
	452
	453	for (j = 0; j < SMALLOC_BPI; j++)
	454	if ((1 << j) & line)
	455	buffer[SMALLOC_BPI-1-j] = '1';
	456	else
	457	buffer[SMALLOC_BPI-1-j] = '0';
	458
	459	log_err("smalloc: bitmap %5u, %s\n", i, buffer);
	460	}
	461
	462	free(buffer);
	463	}
	464
	465	void smalloc_debug(size_t size)
	466	{
	467	unsigned int i;
	468	size_t alloc_size = size_to_alloc_size(size);
	469	size_t alloc_blocks;
	470
	471	alloc_blocks = size_to_blocks(alloc_size);
	472
	473	if (size)
	474	log_err("smalloc: size = %lu, alloc_size = %lu, blocks = %lu\n",
	475	(unsigned long) size, (unsigned long) alloc_size,
	476	(unsigned long) alloc_blocks);
	477	for (i = 0; i < nr_pools; i++) {
	478	log_err("smalloc: pool %u, free/total blocks %u/%u\n", i,
	479	(unsigned int) (mp[i].free_blocks),
	480	(unsigned int) (mp[i].nr_blockssizeof(unsigned int)8));
	481	if (size && mp[i].free_blocks >= alloc_blocks) {
	482	void *ptr = smalloc_pool(&mp[i], size);
	483	if (ptr) {
	484	sfree(ptr);
	485	last_pool = i;
	486	log_err("smalloc: smalloc_pool %u succeeded\n", i);
	487	} else {
	488	log_err("smalloc: smalloc_pool %u failed\n", i);
	489	log_err("smalloc: next_non_full=%u, nr_blocks=%u\n",
	490	(unsigned int) mp[i].next_non_full, (unsigned int) mp[i].nr_blocks);
	491	smalloc_print_bitmap(&mp[i]);
	492	}
	493	}
	494	}
	495	}
	496
	497	void *smalloc(size_t size)
	498	{
	499	unsigned int i, end_pool;
	500
	501	if (size != (unsigned int) size)
	502	return NULL;
	503
	504	i = last_pool;
	505	end_pool = nr_pools;
	506
	507	do {
	508	for (; i < end_pool; i++) {
	509	void *ptr = smalloc_pool(&mp[i], size);
	510
	511	if (ptr) {
	512	last_pool = i;
	513	return ptr;
	514	}
	515	}
	516	if (last_pool) {
	517	end_pool = last_pool;
	518	last_pool = i = 0;
	519	continue;
	520	}
	521
	522	break;
	523	} while (1);
	524
	525	log_err("smalloc: OOM. Consider using --alloc-size to increase the "
	526	"shared memory available.\n");
	527	smalloc_debug(size);
	528	return NULL;
	529	}
	530
	531	void *scalloc(size_t nmemb, size_t size)
	532	{
	533	return smalloc(nmemb * size);
	534	}
	535
	536	char smalloc_strdup(const char str)
	537	{
	538	char *ptr = NULL;
	539
	540	ptr = smalloc(strlen(str) + 1);
	541	if (ptr)
	542	strcpy(ptr, str);
	543	return ptr;
	544	}