#include "mutex.h"
-#undef ENABLE_RESIZE /* define to enable pool resizing */
-#define MP_SAFE /* define to made allocator thread safe */
+#define MP_SAFE /* define to make thread safe */
+#define SMALLOC_REDZONE /* define to detect memory corruption */
-#define INITIAL_SIZE 1048576 /* new pool size */
-#define MAX_POOLS 32 /* maximum number of pools to setup */
+#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)
-#ifdef ENABLE_RESIZE
-#define MAX_SIZE 8 * INITIAL_SIZE
-static unsigned int resize_error;
-#endif
+#define INITIAL_SIZE 1024*1024 /* new pool size */
+#define MAX_POOLS 4 /* maximum number of pools to setup */
+
+#define SMALLOC_PRE_RED 0xdeadbeefU
+#define SMALLOC_POST_RED 0x5aa55aa5U
+
+unsigned int smalloc_pool_size = INITIAL_SIZE;
struct pool {
struct fio_mutex *lock; /* protects this pool */
void *map; /* map of blocks */
- void *last; /* next free block hint */
- unsigned int size; /* size of pool */
- unsigned int room; /* size left in pool */
- unsigned int largest_block; /* largest block free */
- unsigned int free_since_compact; /* sfree() since compact() */
+ unsigned int *bitmap; /* blocks free/busy map */
+ unsigned int free_blocks; /* free blocks */
+ unsigned int nr_blocks; /* total blocks */
+ unsigned int next_non_full;
int fd; /* memory backing fd */
char file[PATH_MAX]; /* filename for fd */
+ unsigned int mmap_size;
+};
+
+struct block_hdr {
+ unsigned int size;
+#ifdef SMALLOC_REDZONE
+ unsigned int prered;
+#endif
};
static struct pool mp[MAX_POOLS];
static unsigned int last_pool;
static struct fio_mutex *lock;
-struct mem_hdr {
- unsigned int size;
-};
-
static inline void pool_lock(struct pool *pool)
{
if (pool->lock)
fio_mutex_up_write(lock);
}
-#define hdr_free(hdr) ((hdr)->size & 0x80000000)
-#define hdr_size(hdr) ((hdr)->size & ~0x80000000)
-#define hdr_mark_free(hdr) ((hdr)->size |= 0x80000000)
-
static inline int ptr_valid(struct pool *pool, void *ptr)
{
- return (ptr >= pool->map) && (ptr < pool->map + pool->size);
-}
+ unsigned int pool_size = pool->nr_blocks * SMALLOC_BPL;
-static inline int __hdr_valid(struct pool *pool, struct mem_hdr *hdr,
- unsigned int size)
-{
- return ptr_valid(pool, hdr) && ptr_valid(pool, (void *) hdr + size - 1);
+ return (ptr >= pool->map) && (ptr < pool->map + pool_size);
}
-static inline int hdr_valid(struct pool *pool, struct mem_hdr *hdr)
+static inline unsigned int size_to_blocks(unsigned int size)
{
- return __hdr_valid(pool, hdr, hdr_size(hdr));
+ return (size + SMALLOC_BPB - 1) / SMALLOC_BPB;
}
-static inline int region_free(struct mem_hdr *hdr)
+static int blocks_iter(struct pool *pool, unsigned int pool_idx,
+ unsigned int idx, unsigned int nr_blocks,
+ int (*func)(unsigned int *map, unsigned int mask))
{
- return hdr_free(hdr) || (!hdr_free(hdr) && !hdr_size(hdr));
-}
-static inline struct mem_hdr *__hdr_nxt(struct pool *pool, struct mem_hdr *hdr,
- unsigned int size)
-{
- struct mem_hdr *nxt = (void *) hdr + size + sizeof(*hdr);
+ while (nr_blocks) {
+ unsigned int this_blocks, mask;
+ unsigned int *map;
- if (__hdr_valid(pool, nxt, size))
- return nxt;
+ if (pool_idx >= pool->nr_blocks)
+ return 0;
- return NULL;
-}
+ map = &pool->bitmap[pool_idx];
-static inline struct mem_hdr *hdr_nxt(struct pool *pool, struct mem_hdr *hdr)
-{
- return __hdr_nxt(pool, hdr, hdr_size(hdr));
-}
+ this_blocks = nr_blocks;
+ if (this_blocks + idx > SMALLOC_BPI) {
+ this_blocks = SMALLOC_BPI - idx;
+ idx = SMALLOC_BPI - this_blocks;
+ }
-static void merge(struct pool *pool, struct mem_hdr *hdr, struct mem_hdr *nxt)
-{
- unsigned int hfree = hdr_free(hdr);
- unsigned int nfree = hdr_free(nxt);
+ if (this_blocks == SMALLOC_BPI)
+ mask = -1U;
+ else
+ mask = ((1U << this_blocks) - 1) << idx;
- hdr->size = hdr_size(hdr) + hdr_size(nxt) + sizeof(*nxt);
- nxt->size = 0;
+ if (!func(map, mask))
+ return 0;
- if (hfree)
- hdr_mark_free(hdr);
- if (nfree)
- hdr_mark_free(nxt);
+ nr_blocks -= this_blocks;
+ idx = 0;
+ pool_idx++;
+ }
- if (pool->last == nxt)
- pool->last = hdr;
+ return 1;
}
-static int combine(struct pool *pool, struct mem_hdr *prv, struct mem_hdr *hdr)
+static int mask_cmp(unsigned int *map, unsigned int mask)
{
- if (prv && hdr_free(prv) && hdr_free(hdr)) {
- merge(pool, prv, hdr);
- return 1;
- }
-
- return 0;
+ return !(*map & mask);
}
-static int compact_pool(struct pool *pool)
+static int mask_clear(unsigned int *map, unsigned int mask)
{
- struct mem_hdr *hdr = pool->map, *nxt;
- unsigned int compacted = 0;
-
- if (pool->free_since_compact < 50)
- return 1;
-
- while (hdr) {
- nxt = hdr_nxt(pool, hdr);
- if (!nxt)
- break;
- if (hdr_free(nxt) && hdr_free(hdr)) {
- merge(pool, hdr, nxt);
- compacted++;
- continue;
- }
- hdr = hdr_nxt(pool, hdr);
- }
+ assert((*map & mask) == mask);
+ *map &= ~mask;
+ return 1;
+}
- pool->free_since_compact = 0;
- return !!compacted;
+static int mask_set(unsigned int *map, unsigned int mask)
+{
+ assert(!(*map & mask));
+ *map |= mask;
+ return 1;
}
-static int resize_pool(struct pool *pool)
+static int blocks_free(struct pool *pool, unsigned int pool_idx,
+ unsigned int idx, unsigned int nr_blocks)
{
-#ifdef ENABLE_RESIZE
- unsigned int new_size = pool->size << 1;
- struct mem_hdr *hdr, *last_hdr;
- void *ptr;
+ return blocks_iter(pool, pool_idx, idx, nr_blocks, mask_cmp);
+}
- if (new_size >= MAX_SIZE || resize_error)
- return 1;
+static void set_blocks(struct pool *pool, unsigned int pool_idx,
+ unsigned int idx, unsigned int nr_blocks)
+{
+ blocks_iter(pool, pool_idx, idx, nr_blocks, mask_set);
+}
- if (ftruncate(pool->fd, new_size) < 0)
- goto fail;
+static void clear_blocks(struct pool *pool, unsigned int pool_idx,
+ unsigned int idx, unsigned int nr_blocks)
+{
+ blocks_iter(pool, pool_idx, idx, nr_blocks, mask_clear);
+}
- ptr = mremap(pool->map, pool->size, new_size, 0);
- if (ptr == MAP_FAILED)
- goto fail;
+static inline int __ffs(int word)
+{
+ int r = 0;
- pool->map = ptr;
- hdr = pool;
- do {
- last_hdr = hdr;
- } while ((hdr = hdr_nxt(hdr)) != NULL);
-
- if (hdr_free(last_hdr)) {
- last_hdr->size = hdr_size(last_hdr) + new_size - pool_size;
- hdr_mark_free(last_hdr);
- } else {
- struct mem_hdr *nxt;
-
- nxt = (void *) last_hdr + hdr_size(last_hdr) + sizeof(*hdr);
- nxt->size = new_size - pool_size - sizeof(*hdr);
- hdr_mark_free(nxt);
+ if (!(word & 0xffff)) {
+ word >>= 16;
+ r += 16;
+ }
+ if (!(word & 0xff)) {
+ word >>= 8;
+ r += 8;
+ }
+ if (!(word & 0xf)) {
+ word >>= 4;
+ r += 4;
+ }
+ if (!(word & 3)) {
+ word >>= 2;
+ r += 2;
+ }
+ if (!(word & 1)) {
+ word >>= 1;
+ r += 1;
}
- pool_room += new_size - pool_size;
- pool_size = new_size;
- return 0;
-fail:
- perror("resize");
- resize_error = 1;
-#else
- return 1;
-#endif
+ return r;
+}
+
+static int find_next_zero(int word, int start)
+{
+ assert(word != -1U);
+ word >>= (start + 1);
+ return __ffs(~word) + start + 1;
}
-static int add_pool(struct pool *pool)
+static int add_pool(struct pool *pool, unsigned int alloc_size)
{
- struct mem_hdr *hdr;
void *ptr;
- int fd;
+ int fd, bitmap_blocks;
strcpy(pool->file, "/tmp/.fio_smalloc.XXXXXX");
fd = mkstemp(pool->file);
if (fd < 0)
goto out_close;
- pool->size = INITIAL_SIZE;
- if (ftruncate(fd, pool->size) < 0)
+#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;
+
+ if (ftruncate(fd, alloc_size) < 0)
goto out_unlink;
- ptr = mmap(NULL, pool->size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+ ptr = mmap(NULL, alloc_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
if (ptr == MAP_FAILED)
goto out_unlink;
- memset(ptr, 0, pool->size);
- pool->map = pool->last = ptr;
+ memset(ptr, 0, alloc_size);
+ pool->map = ptr;
+ pool->bitmap = (void *) ptr + (pool->nr_blocks * SMALLOC_BPL);
#ifdef MP_SAFE
pool->lock = fio_mutex_init(1);
pool->fd = fd;
- hdr = pool->map;
- pool->room = hdr->size = pool->size - sizeof(*hdr);
- pool->largest_block = pool->room;
- hdr_mark_free(hdr);
global_write_lock();
nr_pools++;
global_write_unlock();
return 0;
out_unlink:
+ fprintf(stderr, "smalloc: failed adding pool\n");
if (pool->map)
- munmap(pool->map, pool->size);
+ munmap(pool->map, pool->mmap_size);
unlink(pool->file);
out_close:
if (fd >= 0)
#ifdef MP_SAFE
lock = fio_mutex_rw_init();
#endif
- ret = add_pool(&mp[0]);
+ ret = add_pool(&mp[0], INITIAL_SIZE);
assert(!ret);
}
{
unlink(pool->file);
close(pool->fd);
- munmap(pool->map, pool->size);
+ munmap(pool->map, pool->mmap_size);
if (pool->lock)
fio_mutex_remove(pool->lock);
fio_mutex_remove(lock);
}
+#ifdef SMALLOC_REDZONE
+static void fill_redzone(struct block_hdr *hdr)
+{
+ unsigned int *postred = (void *) hdr + hdr->size - sizeof(unsigned int);
+
+ hdr->prered = SMALLOC_PRE_RED;
+ *postred = SMALLOC_POST_RED;
+}
+
+static void sfree_check_redzone(struct block_hdr *hdr)
+{
+ unsigned int *postred = (void *) hdr + hdr->size - sizeof(unsigned int);
+
+ if (hdr->prered != SMALLOC_PRE_RED) {
+ fprintf(stderr, "smalloc pre redzone destroyed!\n");
+ fprintf(stderr, " ptr=%p, prered=%x, expected %x\n",
+ hdr, hdr->prered, SMALLOC_PRE_RED);
+ assert(0);
+ }
+ if (*postred != SMALLOC_POST_RED) {
+ fprintf(stderr, "smalloc post redzone destroyed!\n");
+ fprintf(stderr, " ptr=%p, postred=%x, expected %x\n",
+ hdr, *postred, SMALLOC_POST_RED);
+ assert(0);
+ }
+}
+#else
+static void fill_redzone(struct block_hdr *hdr)
+{
+}
+
+static void sfree_check_redzone(struct block_hdr *hdr)
+{
+}
+#endif
+
static void sfree_pool(struct pool *pool, void *ptr)
{
- struct mem_hdr *hdr, *nxt;
+ struct block_hdr *hdr;
+ unsigned int i, idx;
+ unsigned long offset;
if (!ptr)
return;
- assert(ptr_valid(pool, ptr));
+ ptr -= sizeof(*hdr);
+ hdr = ptr;
- pool_lock(pool);
- hdr = ptr - sizeof(*hdr);
- assert(!hdr_free(hdr));
- hdr_mark_free(hdr);
- pool->room -= hdr_size(hdr);
+ assert(ptr_valid(pool, ptr));
- nxt = hdr_nxt(pool, hdr);
- if (nxt && hdr_free(nxt))
- merge(pool, hdr, nxt);
+ sfree_check_redzone(hdr);
- if (hdr_size(hdr) > pool->largest_block)
- pool->largest_block = hdr_size(hdr);
+ offset = ptr - pool->map;
+ i = offset / SMALLOC_BPL;
+ idx = (offset % SMALLOC_BPL) / SMALLOC_BPB;
- pool->free_since_compact++;
+ pool_lock(pool);
+ clear_blocks(pool, i, idx, size_to_blocks(hdr->size));
+ if (i < pool->next_non_full)
+ pool->next_non_full = i;
+ pool->free_blocks += size_to_blocks(hdr->size);
pool_unlock(pool);
}
struct pool *pool = NULL;
unsigned int i;
+ if (!ptr)
+ return;
+
global_read_lock();
for (i = 0; i < nr_pools; i++) {
sfree_pool(pool, ptr);
}
-static void *smalloc_pool(struct pool *pool, unsigned int size)
+static void *__smalloc_pool(struct pool *pool, unsigned int size)
{
- struct mem_hdr *hdr, *prv;
- int did_restart = 0;
- void *ret;
-
- /*
- * slight chance of race with sfree() here, but acceptable
- */
- if (!size || size > pool->room + sizeof(*hdr) ||
- ((size > pool->largest_block) && pool->largest_block))
- return NULL;
+ unsigned int nr_blocks;
+ unsigned int i;
+ unsigned int offset;
+ unsigned int last_idx;
+ void *ret = NULL;
pool_lock(pool);
-restart:
- hdr = pool->last;
- prv = NULL;
- do {
- if (combine(pool, prv, hdr))
- hdr = prv;
- if (hdr_free(hdr) && hdr_size(hdr) >= size)
- break;
-
- prv = hdr;
- } while ((hdr = hdr_nxt(pool, hdr)) != NULL);
-
- if (!hdr)
+ nr_blocks = size_to_blocks(size);
+ if (nr_blocks > pool->free_blocks)
goto fail;
- /*
- * more room, adjust next header if any
- */
- if (hdr_size(hdr) - size >= 2 * sizeof(*hdr)) {
- struct mem_hdr *nxt = __hdr_nxt(pool, hdr, size);
-
- if (nxt) {
- nxt->size = hdr_size(hdr) - size - sizeof(*hdr);
- if (hdr_size(hdr) == pool->largest_block)
- pool->largest_block = hdr_size(nxt);
- hdr_mark_free(nxt);
- } else
- size = hdr_size(hdr);
- } else
- size = hdr_size(hdr);
-
- if (size == hdr_size(hdr) && size == pool->largest_block)
- pool->largest_block = 0;
-
- /*
- * also clears free bit
- */
- hdr->size = size;
- pool->last = hdr_nxt(pool, hdr);
- if (!pool->last)
- pool->last = pool->map;
- pool->room -= size;
- pool_unlock(pool);
+ i = pool->next_non_full;
+ last_idx = 0;
+ offset = -1U;
+ while (i < pool->nr_blocks) {
+ unsigned int idx;
- ret = (void *) hdr + sizeof(*hdr);
- memset(ret, 0, size);
- return ret;
-fail:
- /*
- * if we fail to allocate, first compact the entries that we missed.
- * if that also fails, increase the size of the pool
- */
- ++did_restart;
- if (did_restart <= 1) {
- if (!compact_pool(pool)) {
- pool->last = pool->map;
- goto restart;
+ if (pool->bitmap[i] == -1U) {
+ i++;
+ pool->next_non_full = i;
+ last_idx = 0;
+ continue;
}
- }
- ++did_restart;
- if (did_restart <= 2) {
- if (!resize_pool(pool)) {
- pool->last = pool->map;
- goto restart;
+
+ idx = find_next_zero(pool->bitmap[i], last_idx);
+ if (!blocks_free(pool, i, idx, nr_blocks)) {
+ idx += nr_blocks;
+ if (idx < SMALLOC_BPI)
+ last_idx = idx;
+ else {
+ last_idx = 0;
+ while (idx >= SMALLOC_BPI) {
+ i++;
+ idx -= SMALLOC_BPI;
+ }
+ }
+ continue;
}
+ set_blocks(pool, i, idx, nr_blocks);
+ offset = i * SMALLOC_BPL + idx * SMALLOC_BPB;
+ break;
}
+
+ if (i < pool->nr_blocks) {
+ pool->free_blocks -= nr_blocks;
+ ret = pool->map + offset;
+ }
+fail:
pool_unlock(pool);
- return NULL;
+ return ret;
+}
+
+static void *smalloc_pool(struct pool *pool, unsigned int size)
+{
+ unsigned int alloc_size = size + sizeof(struct block_hdr);
+ void *ptr;
+
+#ifdef SMALLOC_REDZONE
+ alloc_size += sizeof(unsigned int);
+#endif
+
+ ptr = __smalloc_pool(pool, alloc_size);
+ if (ptr) {
+ struct block_hdr *hdr = ptr;
+
+ hdr->size = alloc_size;
+ fill_redzone(hdr);
+
+ ptr += sizeof(*hdr);
+ memset(ptr, 0, size);
+ }
+
+ return ptr;
}
void *smalloc(unsigned int size)
continue;
}
- if (nr_pools + 1 >= MAX_POOLS)
+ if (nr_pools + 1 > MAX_POOLS)
break;
else {
i = nr_pools;
global_read_unlock();
- if (add_pool(&mp[nr_pools]))
+ if (add_pool(&mp[nr_pools], size))
goto out;
global_read_lock();
}
projects / fio.git / blobdiff