[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;
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_BPI;

	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;

	/*
	 * sinit() can be called more than once if alloc-size is
	 * set. But we want to allocate space for the struct pool
	 * instances only once.
	 */
	if (!mp) {
		mp = (struct pool *) mmap(NULL,
			MAX_POOLS * sizeof(struct pool),
			PROT_READ | PROT_WRITE,
			OS_MAP_ANON | MAP_SHARED, -1, 0);

		assert(mp != MAP_FAILED);
	}

	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]);

	munmap(mp, MAX_POOLS * sizeof(struct pool));
}

#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+1, 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+1, *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 unsigned int find_best_index(struct pool *pool)
{
	unsigned int i;

	assert(pool->free_blocks);

	for (i = pool->next_non_full; pool->bitmap[i] == -1U; i++) {
		if (i == pool->nr_blocks - 1) {
			unsigned int j;

			for (j = 0; j < pool->nr_blocks; j++)
				if (pool->bitmap[j] != -1U)
					return j;
		}
	}

	return i;
}

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;

	pool->next_non_full = find_best_index(pool);

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

		if (pool->bitmap[i] == -1U) {
			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;
	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_BPI;
	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	/*
	212	* sinit() can be called more than once if alloc-size is
	213	* set. But we want to allocate space for the struct pool
	214	* instances only once.
	215	*/
	216	if (!mp) {
	217	mp = (struct pool *) mmap(NULL,
	218	MAX_POOLS * sizeof(struct pool),
	219	PROT_READ \| PROT_WRITE,
	220	OS_MAP_ANON \| MAP_SHARED, -1, 0);
	221
	222	assert(mp != MAP_FAILED);
	223	}
	224
	225	for (i = 0; i < INITIAL_POOLS; i++) {
	226	ret = add_pool(&mp[nr_pools], smalloc_pool_size);
	227	if (!ret)
	228	break;
	229	}
	230
	231	/*
	232	* If we added at least one pool, we should be OK for most
	233	* cases.
	234	*/
	235	assert(i);
	236	}
	237
	238	static void cleanup_pool(struct pool *pool)
	239	{
	240	/*
	241	* This will also remove the temporary file we used as a backing
	242	* store, it was already unlinked
	243	*/
	244	munmap(pool->map, pool->mmap_size);
	245
	246	if (pool->lock)
	247	fio_sem_remove(pool->lock);
	248	}
	249
	250	void scleanup(void)
	251	{
	252	unsigned int i;
	253
	254	for (i = 0; i < nr_pools; i++)
	255	cleanup_pool(&mp[i]);
	256
	257	munmap(mp, MAX_POOLS * sizeof(struct pool));
	258	}
	259
	260	#ifdef SMALLOC_REDZONE
	261	static void postred_ptr(struct block_hdr hdr)
	262	{
	263	uintptr_t ptr;
	264
	265	ptr = (uintptr_t) hdr + hdr->size - sizeof(unsigned int);
	266	ptr = (uintptr_t) PTR_ALIGN(ptr, int_mask);
	267
	268	return (void *) ptr;
	269	}
	270
	271	static void fill_redzone(struct block_hdr *hdr)
	272	{
	273	unsigned int *postred = postred_ptr(hdr);
	274
	275	hdr->prered = SMALLOC_PRE_RED;
	276	*postred = SMALLOC_POST_RED;
	277	}
	278
	279	static void sfree_check_redzone(struct block_hdr *hdr)
	280	{
	281	unsigned int *postred = postred_ptr(hdr);
	282
	283	if (hdr->prered != SMALLOC_PRE_RED) {
	284	log_err("smalloc pre redzone destroyed!\n"
	285	" ptr=%p, prered=%x, expected %x\n",
	286	hdr+1, hdr->prered, SMALLOC_PRE_RED);
	287	assert(0);
	288	}
	289	if (*postred != SMALLOC_POST_RED) {
	290	log_err("smalloc post redzone destroyed!\n"
	291	" ptr=%p, postred=%x, expected %x\n",
	292	hdr+1, *postred, SMALLOC_POST_RED);
	293	assert(0);
	294	}
	295	}
	296	#else
	297	static void fill_redzone(struct block_hdr *hdr)
	298	{
	299	}
	300
	301	static void sfree_check_redzone(struct block_hdr *hdr)
	302	{
	303	}
	304	#endif
	305
	306	static void sfree_pool(struct pool pool, void ptr)
	307	{
	308	struct block_hdr *hdr;
	309	unsigned int i, idx;
	310	unsigned long offset;
	311
	312	if (!ptr)
	313	return;
	314
	315	ptr -= sizeof(*hdr);
	316	hdr = ptr;
	317
	318	assert(ptr_valid(pool, ptr));
	319
	320	sfree_check_redzone(hdr);
	321
	322	offset = ptr - pool->map;
	323	i = offset / SMALLOC_BPL;
	324	idx = (offset % SMALLOC_BPL) / SMALLOC_BPB;
	325
	326	fio_sem_down(pool->lock);
	327	clear_blocks(pool, i, idx, size_to_blocks(hdr->size));
	328	if (i < pool->next_non_full)
	329	pool->next_non_full = i;
	330	pool->free_blocks += size_to_blocks(hdr->size);
	331	fio_sem_up(pool->lock);
	332	}
	333
	334	void sfree(void *ptr)
	335	{
	336	struct pool *pool = NULL;
	337	unsigned int i;
	338
	339	if (!ptr)
	340	return;
	341
	342	for (i = 0; i < nr_pools; i++) {
	343	if (ptr_valid(&mp[i], ptr)) {
	344	pool = &mp[i];
	345	break;
	346	}
	347	}
	348
	349	if (pool) {
	350	sfree_pool(pool, ptr);
	351	return;
	352	}
	353
	354	log_err("smalloc: ptr %p not from smalloc pool\n", ptr);
	355	}
	356
	357	static unsigned int find_best_index(struct pool *pool)
	358	{
	359	unsigned int i;
	360
	361	assert(pool->free_blocks);
	362
	363	for (i = pool->next_non_full; pool->bitmap[i] == -1U; i++) {
	364	if (i == pool->nr_blocks - 1) {
	365	unsigned int j;
	366
	367	for (j = 0; j < pool->nr_blocks; j++)
	368	if (pool->bitmap[j] != -1U)
	369	return j;
	370	}
	371	}
	372
	373	return i;
	374	}
	375
	376	static void __smalloc_pool(struct pool pool, size_t size)
	377	{
	378	size_t nr_blocks;
	379	unsigned int i;
	380	unsigned int offset;
	381	unsigned int last_idx;
	382	void *ret = NULL;
	383
	384	fio_sem_down(pool->lock);
	385
	386	nr_blocks = size_to_blocks(size);
	387	if (nr_blocks > pool->free_blocks)
	388	goto fail;
	389
	390	pool->next_non_full = find_best_index(pool);
	391
	392	last_idx = 0;
	393	offset = -1U;
	394	i = pool->next_non_full;
	395	while (i < pool->nr_blocks) {
	396	unsigned int idx;
	397
	398	if (pool->bitmap[i] == -1U) {
	399	i++;
	400	last_idx = 0;
	401	continue;
	402	}
	403
	404	idx = find_next_zero(pool->bitmap[i], last_idx);
	405	if (!blocks_free(pool, i, idx, nr_blocks)) {
	406	idx += nr_blocks;
	407	if (idx < SMALLOC_BPI)
	408	last_idx = idx;
	409	else {
	410	last_idx = 0;
	411	while (idx >= SMALLOC_BPI) {
	412	i++;
	413	idx -= SMALLOC_BPI;
	414	}
	415	}
	416	continue;
	417	}
	418	set_blocks(pool, i, idx, nr_blocks);
	419	offset = i * SMALLOC_BPL + idx * SMALLOC_BPB;
	420	break;
	421	}
	422
	423	if (i < pool->nr_blocks) {
	424	pool->free_blocks -= nr_blocks;
	425	ret = pool->map + offset;
	426	}
	427	fail:
	428	fio_sem_up(pool->lock);
	429	return ret;
	430	}
	431
	432	static size_t size_to_alloc_size(size_t size)
	433	{
	434	size_t alloc_size = size + sizeof(struct block_hdr);
	435
	436	/*
	437	* Round to int alignment, so that the postred pointer will
	438	* be naturally aligned as well.
	439	*/
	440	#ifdef SMALLOC_REDZONE
	441	alloc_size += sizeof(unsigned int);
	442	alloc_size = (alloc_size + int_mask) & ~int_mask;
	443	#endif
	444
	445	return alloc_size;
	446	}
	447
	448	static void smalloc_pool(struct pool pool, size_t size)
	449	{
	450	size_t alloc_size = size_to_alloc_size(size);
	451	void *ptr;
	452
	453	ptr = __smalloc_pool(pool, alloc_size);
	454	if (ptr) {
	455	struct block_hdr *hdr = ptr;
	456
	457	hdr->size = alloc_size;
	458	fill_redzone(hdr);
	459
	460	ptr += sizeof(*hdr);
	461	memset(ptr, 0, size);
	462	}
	463
	464	return ptr;
	465	}
	466
	467	static void smalloc_print_bitmap(struct pool *pool)
	468	{
	469	size_t nr_blocks = pool->nr_blocks;
	470	unsigned int *bitmap = pool->bitmap;
	471	unsigned int i, j;
	472	char *buffer;
	473
	474	if (!enable_smalloc_debug)
	475	return;
	476
	477	buffer = malloc(SMALLOC_BPI + 1);
	478	if (!buffer)
	479	return;
	480	buffer[SMALLOC_BPI] = '\0';
	481
	482	for (i = 0; i < nr_blocks; i++) {
	483	unsigned int line = bitmap[i];
	484
	485	/* skip completely full lines */
	486	if (line == -1U)
	487	continue;
	488
	489	for (j = 0; j < SMALLOC_BPI; j++)
	490	if ((1 << j) & line)
	491	buffer[SMALLOC_BPI-1-j] = '1';
	492	else
	493	buffer[SMALLOC_BPI-1-j] = '0';
	494
	495	log_err("smalloc: bitmap %5u, %s\n", i, buffer);
	496	}
	497
	498	free(buffer);
	499	}
	500
	501	void smalloc_debug(size_t size)
	502	{
	503	unsigned int i;
	504	size_t alloc_size = size_to_alloc_size(size);
	505	size_t alloc_blocks;
	506
	507	alloc_blocks = size_to_blocks(alloc_size);
	508
	509	if (size)
	510	log_err("smalloc: size = %lu, alloc_size = %lu, blocks = %lu\n",
	511	(unsigned long) size, (unsigned long) alloc_size,
	512	(unsigned long) alloc_blocks);
	513	for (i = 0; i < nr_pools; i++) {
	514	log_err("smalloc: pool %u, free/total blocks %u/%u\n", i,
	515	(unsigned int) (mp[i].free_blocks),
	516	(unsigned int) (mp[i].nr_blockssizeof(unsigned int)8));
	517	if (size && mp[i].free_blocks >= alloc_blocks) {
	518	void *ptr = smalloc_pool(&mp[i], size);
	519	if (ptr) {
	520	sfree(ptr);
	521	last_pool = i;
	522	log_err("smalloc: smalloc_pool %u succeeded\n", i);
	523	} else {
	524	log_err("smalloc: smalloc_pool %u failed\n", i);
	525	log_err("smalloc: next_non_full=%u, nr_blocks=%u\n",
	526	(unsigned int) mp[i].next_non_full, (unsigned int) mp[i].nr_blocks);
	527	smalloc_print_bitmap(&mp[i]);
	528	}
	529	}
	530	}
	531	}
	532
	533	void *smalloc(size_t size)
	534	{
	535	unsigned int i, end_pool;
	536
	537	if (size != (unsigned int) size)
	538	return NULL;
	539
	540	i = last_pool;
	541	end_pool = nr_pools;
	542
	543	do {
	544	for (; i < end_pool; i++) {
	545	void *ptr = smalloc_pool(&mp[i], size);
	546
	547	if (ptr) {
	548	last_pool = i;
	549	return ptr;
	550	}
	551	}
	552	if (last_pool) {
	553	end_pool = last_pool;
	554	last_pool = i = 0;
	555	continue;
	556	}
	557
	558	break;
	559	} while (1);
	560
	561	log_err("smalloc: OOM. Consider using --alloc-size to increase the "
	562	"shared memory available.\n");
	563	smalloc_debug(size);
	564	return NULL;
	565	}
	566
	567	void *scalloc(size_t nmemb, size_t size)
	568	{
	569	return smalloc(nmemb * size);
	570	}
	571
	572	char smalloc_strdup(const char str)
	573	{
	574	char *ptr = NULL;
	575
	576	ptr = smalloc(strlen(str) + 1);
	577	if (ptr)
	578	strcpy(ptr, str);
	579	return ptr;
	580	}