nrfiles vs nr_files mixups
[fio.git] / smalloc.c
CommitLineData
d24c33a4
JA
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 <sys/types.h>
12#include <limits.h>
3a8600b4 13#include <fcntl.h>
d24c33a4 14
6548f47f 15#include "mutex.h"
b3268b92 16#include "arch/arch.h"
3a8600b4 17#include "os/os.h"
d24c33a4 18
55f6491d 19#define SMALLOC_REDZONE /* define to detect memory corruption */
d24c33a4 20
ec996e9c
JA
21#define SMALLOC_BPB 32 /* block size, bytes-per-bit in bitmap */
22#define SMALLOC_BPI (sizeof(unsigned int) * 8)
23#define SMALLOC_BPL (SMALLOC_BPB * SMALLOC_BPI)
24
5e012980 25#define INITIAL_SIZE 8192*1024 /* new pool size */
68857686 26#define MAX_POOLS 128 /* maximum number of pools to setup */
d24c33a4 27
55f6491d
JA
28#define SMALLOC_PRE_RED 0xdeadbeefU
29#define SMALLOC_POST_RED 0x5aa55aa5U
55f6491d 30
2b386d25 31unsigned int smalloc_pool_size = INITIAL_SIZE;
122426da 32const int int_mask = sizeof(int) - 1;
2b386d25 33
d24c33a4 34struct pool {
6548f47f 35 struct fio_mutex *lock; /* protects this pool */
d24c33a4 36 void *map; /* map of blocks */
ec996e9c
JA
37 unsigned int *bitmap; /* blocks free/busy map */
38 unsigned int free_blocks; /* free blocks */
39 unsigned int nr_blocks; /* total blocks */
40 unsigned int next_non_full;
d24c33a4 41 int fd; /* memory backing fd */
ec996e9c
JA
42 unsigned int mmap_size;
43};
44
45struct block_hdr {
46 unsigned int size;
47#ifdef SMALLOC_REDZONE
48 unsigned int prered;
49#endif
d24c33a4
JA
50};
51
52static struct pool mp[MAX_POOLS];
53static unsigned int nr_pools;
54static unsigned int last_pool;
6548f47f 55static struct fio_mutex *lock;
d24c33a4 56
d24c33a4
JA
57static inline void pool_lock(struct pool *pool)
58{
2e3e31e3 59 fio_mutex_down(pool->lock);
d24c33a4
JA
60}
61
62static inline void pool_unlock(struct pool *pool)
63{
2e3e31e3 64 fio_mutex_up(pool->lock);
d24c33a4
JA
65}
66
65864cf7 67static inline void global_read_lock(void)
d24c33a4 68{
2e3e31e3 69 fio_mutex_down_read(lock);
d24c33a4
JA
70}
71
65864cf7 72static inline void global_read_unlock(void)
d24c33a4 73{
2e3e31e3 74 fio_mutex_up_read(lock);
65864cf7
JA
75}
76
77static inline void global_write_lock(void)
78{
2e3e31e3 79 fio_mutex_down_write(lock);
65864cf7
JA
80}
81
82static inline void global_write_unlock(void)
83{
2e3e31e3 84 fio_mutex_up_write(lock);
d24c33a4
JA
85}
86
d24c33a4
JA
87static inline int ptr_valid(struct pool *pool, void *ptr)
88{
dcb69098 89 unsigned int pool_size = pool->nr_blocks * SMALLOC_BPL;
ec996e9c
JA
90
91 return (ptr >= pool->map) && (ptr < pool->map + pool_size);
d24c33a4
JA
92}
93
808e9ea8
JA
94static inline unsigned int size_to_blocks(unsigned int size)
95{
96 return (size + SMALLOC_BPB - 1) / SMALLOC_BPB;
97}
98
dcb69098
JA
99static int blocks_iter(struct pool *pool, unsigned int pool_idx,
100 unsigned int idx, unsigned int nr_blocks,
ec996e9c 101 int (*func)(unsigned int *map, unsigned int mask))
d24c33a4 102{
dcb69098 103
ec996e9c
JA
104 while (nr_blocks) {
105 unsigned int this_blocks, mask;
dcb69098
JA
106 unsigned int *map;
107
108 if (pool_idx >= pool->nr_blocks)
109 return 0;
110
111 map = &pool->bitmap[pool_idx];
ec996e9c
JA
112
113 this_blocks = nr_blocks;
114 if (this_blocks + idx > SMALLOC_BPI) {
115 this_blocks = SMALLOC_BPI - idx;
116 idx = SMALLOC_BPI - this_blocks;
117 }
118
119 if (this_blocks == SMALLOC_BPI)
120 mask = -1U;
121 else
122 mask = ((1U << this_blocks) - 1) << idx;
123
124 if (!func(map, mask))
125 return 0;
126
127 nr_blocks -= this_blocks;
128 idx = 0;
dcb69098 129 pool_idx++;
ec996e9c
JA
130 }
131
132 return 1;
d24c33a4
JA
133}
134
ec996e9c 135static int mask_cmp(unsigned int *map, unsigned int mask)
d24c33a4 136{
ec996e9c 137 return !(*map & mask);
d24c33a4
JA
138}
139
ec996e9c 140static int mask_clear(unsigned int *map, unsigned int mask)
d24c33a4 141{
dcb69098 142 assert((*map & mask) == mask);
ec996e9c
JA
143 *map &= ~mask;
144 return 1;
d24c33a4
JA
145}
146
ec996e9c 147static int mask_set(unsigned int *map, unsigned int mask)
d24c33a4 148{
dcb69098 149 assert(!(*map & mask));
ec996e9c
JA
150 *map |= mask;
151 return 1;
d24c33a4
JA
152}
153
dcb69098
JA
154static int blocks_free(struct pool *pool, unsigned int pool_idx,
155 unsigned int idx, unsigned int nr_blocks)
d24c33a4 156{
dcb69098 157 return blocks_iter(pool, pool_idx, idx, nr_blocks, mask_cmp);
d24c33a4
JA
158}
159
dcb69098
JA
160static void set_blocks(struct pool *pool, unsigned int pool_idx,
161 unsigned int idx, unsigned int nr_blocks)
d24c33a4 162{
dcb69098 163 blocks_iter(pool, pool_idx, idx, nr_blocks, mask_set);
d24c33a4
JA
164}
165
dcb69098
JA
166static void clear_blocks(struct pool *pool, unsigned int pool_idx,
167 unsigned int idx, unsigned int nr_blocks)
d24c33a4 168{
dcb69098 169 blocks_iter(pool, pool_idx, idx, nr_blocks, mask_clear);
d24c33a4
JA
170}
171
ec996e9c
JA
172static int find_next_zero(int word, int start)
173{
174 assert(word != -1U);
175 word >>= (start + 1);
b3268b92 176 return ffz(word) + start + 1;
d24c33a4
JA
177}
178
adf57099 179static int add_pool(struct pool *pool, unsigned int alloc_size)
d24c33a4 180{
c0e75abf 181 int fd, bitmap_blocks;
b8a6582e
JA
182 char file[] = "/tmp/.fio_smalloc.XXXXXX";
183 void *ptr;
ec996e9c 184
b8a6582e 185 fd = mkstemp(file);
d24c33a4
JA
186 if (fd < 0)
187 goto out_close;
188
55f6491d 189#ifdef SMALLOC_REDZONE
ec996e9c 190 alloc_size += sizeof(unsigned int);
55f6491d 191#endif
ec996e9c
JA
192 alloc_size += sizeof(struct block_hdr);
193 if (alloc_size < INITIAL_SIZE)
194 alloc_size = INITIAL_SIZE;
195
196 /* round up to nearest full number of blocks */
197 alloc_size = (alloc_size + SMALLOC_BPL - 1) & ~(SMALLOC_BPL - 1);
198 bitmap_blocks = alloc_size / SMALLOC_BPL;
199 alloc_size += bitmap_blocks * sizeof(unsigned int);
200 pool->mmap_size = alloc_size;
0b9d69ec 201
ec996e9c
JA
202 pool->nr_blocks = bitmap_blocks;
203 pool->free_blocks = bitmap_blocks * SMALLOC_BPB;
adf57099 204
3a8600b4 205#ifdef FIO_HAVE_FALLOCATE
c0e75abf
JA
206 {
207 int ret;
208
209 ret = posix_fallocate(fd, 0, alloc_size);
210 if (ret > 0) {
211 fprintf(stderr, "posix_fallocate pool file failed: %s\n", strerror(ret));
212 goto out_unlink;
213 }
3a8600b4
GE
214 }
215#endif
216
ec996e9c 217 if (ftruncate(fd, alloc_size) < 0)
d24c33a4
JA
218 goto out_unlink;
219
ec996e9c 220 ptr = mmap(NULL, alloc_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
d24c33a4
JA
221 if (ptr == MAP_FAILED)
222 goto out_unlink;
223
ec996e9c
JA
224 memset(ptr, 0, alloc_size);
225 pool->map = ptr;
226 pool->bitmap = (void *) ptr + (pool->nr_blocks * SMALLOC_BPL);
d24c33a4 227
6548f47f 228 pool->lock = fio_mutex_init(1);
d24c33a4
JA
229 if (!pool->lock)
230 goto out_unlink;
d24c33a4 231
443bb114
JA
232 /*
233 * Unlink pool file now. It wont get deleted until the fd is closed,
234 * which happens both for cleanup or unexpected quit. This way we
235 * don't leave temp files around in case of a crash.
236 */
b8a6582e 237 unlink(file);
d24c33a4
JA
238 pool->fd = fd;
239
d24c33a4
JA
240 nr_pools++;
241 return 0;
242out_unlink:
ec996e9c 243 fprintf(stderr, "smalloc: failed adding pool\n");
d24c33a4 244 if (pool->map)
ec996e9c 245 munmap(pool->map, pool->mmap_size);
b8a6582e 246 unlink(file);
d24c33a4 247out_close:
b8a6582e 248 close(fd);
d24c33a4
JA
249 return 1;
250}
251
252void sinit(void)
253{
4d4e80f2 254 int ret;
d24c33a4 255
6548f47f 256 lock = fio_mutex_rw_init();
adf57099 257 ret = add_pool(&mp[0], INITIAL_SIZE);
d24c33a4
JA
258 assert(!ret);
259}
260
261static void cleanup_pool(struct pool *pool)
262{
443bb114
JA
263 /*
264 * This will also remove the temporary file we used as a backing
265 * store, it was already unlinked
266 */
d24c33a4 267 close(pool->fd);
ec996e9c 268 munmap(pool->map, pool->mmap_size);
6548f47f
JA
269
270 if (pool->lock)
271 fio_mutex_remove(pool->lock);
d24c33a4
JA
272}
273
274void scleanup(void)
275{
276 unsigned int i;
277
278 for (i = 0; i < nr_pools; i++)
279 cleanup_pool(&mp[i]);
280
6548f47f
JA
281 if (lock)
282 fio_mutex_remove(lock);
d24c33a4
JA
283}
284
89da54e8 285#ifdef SMALLOC_REDZONE
cf98708d
JA
286static void *postred_ptr(struct block_hdr *hdr)
287{
cf98708d
JA
288 unsigned long ptr;
289
290 ptr = (unsigned long) hdr + hdr->size - sizeof(unsigned int);
291 ptr = (ptr + int_mask) & ~int_mask;
292
293 return (void *) ptr;
294}
295
ec996e9c 296static void fill_redzone(struct block_hdr *hdr)
55f6491d 297{
cf98708d 298 unsigned int *postred = postred_ptr(hdr);
55f6491d 299
ec996e9c
JA
300 hdr->prered = SMALLOC_PRE_RED;
301 *postred = SMALLOC_POST_RED;
ec996e9c 302}
55f6491d 303
ec996e9c
JA
304static void sfree_check_redzone(struct block_hdr *hdr)
305{
cf98708d 306 unsigned int *postred = postred_ptr(hdr);
ec996e9c
JA
307
308 if (hdr->prered != SMALLOC_PRE_RED) {
55f6491d
JA
309 fprintf(stderr, "smalloc pre redzone destroyed!\n");
310 fprintf(stderr, " ptr=%p, prered=%x, expected %x\n",
ec996e9c 311 hdr, hdr->prered, SMALLOC_PRE_RED);
55f6491d
JA
312 assert(0);
313 }
314 if (*postred != SMALLOC_POST_RED) {
315 fprintf(stderr, "smalloc post redzone destroyed!\n");
316 fprintf(stderr, " ptr=%p, postred=%x, expected %x\n",
ec996e9c 317 hdr, *postred, SMALLOC_POST_RED);
55f6491d
JA
318 assert(0);
319 }
89da54e8
JA
320}
321#else
322static void fill_redzone(struct block_hdr *hdr)
323{
55f6491d
JA
324}
325
89da54e8
JA
326static void sfree_check_redzone(struct block_hdr *hdr)
327{
328}
329#endif
330
d24c33a4
JA
331static void sfree_pool(struct pool *pool, void *ptr)
332{
ec996e9c 333 struct block_hdr *hdr;
179446e0 334 unsigned int i, idx;
ec996e9c 335 unsigned long offset;
d24c33a4
JA
336
337 if (!ptr)
338 return;
339
ec996e9c
JA
340 ptr -= sizeof(*hdr);
341 hdr = ptr;
55f6491d 342
d24c33a4
JA
343 assert(ptr_valid(pool, ptr));
344
ec996e9c 345 sfree_check_redzone(hdr);
d24c33a4 346
ec996e9c
JA
347 offset = ptr - pool->map;
348 i = offset / SMALLOC_BPL;
349 idx = (offset % SMALLOC_BPL) / SMALLOC_BPB;
d24c33a4 350
ec996e9c 351 pool_lock(pool);
dcb69098 352 clear_blocks(pool, i, idx, size_to_blocks(hdr->size));
ec996e9c
JA
353 if (i < pool->next_non_full)
354 pool->next_non_full = i;
179446e0 355 pool->free_blocks += size_to_blocks(hdr->size);
d24c33a4
JA
356 pool_unlock(pool);
357}
358
359void sfree(void *ptr)
360{
361 struct pool *pool = NULL;
362 unsigned int i;
363
8e5732e5
JA
364 if (!ptr)
365 return;
366
65864cf7 367 global_read_lock();
d24c33a4
JA
368
369 for (i = 0; i < nr_pools; i++) {
370 if (ptr_valid(&mp[i], ptr)) {
371 pool = &mp[i];
372 break;
373 }
374 }
375
65864cf7 376 global_read_unlock();
d24c33a4
JA
377
378 assert(pool);
379 sfree_pool(pool, ptr);
380}
381
55f6491d 382static void *__smalloc_pool(struct pool *pool, unsigned int size)
d24c33a4 383{
ec996e9c
JA
384 unsigned int nr_blocks;
385 unsigned int i;
386 unsigned int offset;
387 unsigned int last_idx;
388 void *ret = NULL;
d24c33a4 389
d24c33a4 390 pool_lock(pool);
179446e0
JA
391
392 nr_blocks = size_to_blocks(size);
ec996e9c 393 if (nr_blocks > pool->free_blocks)
8e5732e5 394 goto fail;
5ec10eaa 395
ec996e9c
JA
396 i = pool->next_non_full;
397 last_idx = 0;
398 offset = -1U;
399 while (i < pool->nr_blocks) {
400 unsigned int idx;
d24c33a4 401
ec996e9c
JA
402 if (pool->bitmap[i] == -1U) {
403 i++;
404 pool->next_non_full = i;
405 last_idx = 0;
406 continue;
407 }
d24c33a4 408
ec996e9c 409 idx = find_next_zero(pool->bitmap[i], last_idx);
dcb69098 410 if (!blocks_free(pool, i, idx, nr_blocks)) {
ec996e9c
JA
411 idx += nr_blocks;
412 if (idx < SMALLOC_BPI)
413 last_idx = idx;
414 else {
415 last_idx = 0;
416 while (idx >= SMALLOC_BPI) {
417 i++;
418 idx -= SMALLOC_BPI;
419 }
420 }
421 continue;
d24c33a4 422 }
dcb69098 423 set_blocks(pool, i, idx, nr_blocks);
ec996e9c
JA
424 offset = i * SMALLOC_BPL + idx * SMALLOC_BPB;
425 break;
426 }
427
428 if (i < pool->nr_blocks) {
429 pool->free_blocks -= nr_blocks;
430 ret = pool->map + offset;
d24c33a4 431 }
ec996e9c 432fail:
d24c33a4 433 pool_unlock(pool);
ec996e9c 434 return ret;
d24c33a4
JA
435}
436
55f6491d
JA
437static void *smalloc_pool(struct pool *pool, unsigned int size)
438{
89da54e8 439 unsigned int alloc_size = size + sizeof(struct block_hdr);
55f6491d
JA
440 void *ptr;
441
cf98708d 442 /*
122426da
JA
443 * Round to int alignment, so that the postred pointer will
444 * be naturally aligned as well.
cf98708d 445 */
ec996e9c 446#ifdef SMALLOC_REDZONE
122426da
JA
447 alloc_size += sizeof(unsigned int);
448 alloc_size = (alloc_size + int_mask) & ~int_mask;
ec996e9c
JA
449#endif
450
451 ptr = __smalloc_pool(pool, alloc_size);
89da54e8
JA
452 if (ptr) {
453 struct block_hdr *hdr = ptr;
55f6491d 454
89da54e8
JA
455 hdr->size = alloc_size;
456 fill_redzone(hdr);
55f6491d 457
89da54e8
JA
458 ptr += sizeof(*hdr);
459 memset(ptr, 0, size);
460 }
ec996e9c 461
55f6491d 462 return ptr;
55f6491d
JA
463}
464
d24c33a4
JA
465void *smalloc(unsigned int size)
466{
467 unsigned int i;
468
d1271dc1 469 global_write_lock();
d24c33a4
JA
470 i = last_pool;
471
472 do {
473 for (; i < nr_pools; i++) {
474 void *ptr = smalloc_pool(&mp[i], size);
475
476 if (ptr) {
477 last_pool = i;
d1271dc1 478 global_write_unlock();
d24c33a4
JA
479 return ptr;
480 }
481 }
482 if (last_pool) {
483 last_pool = 0;
484 continue;
485 }
486
ec996e9c 487 if (nr_pools + 1 > MAX_POOLS)
d24c33a4
JA
488 break;
489 else {
490 i = nr_pools;
adf57099 491 if (add_pool(&mp[nr_pools], size))
65864cf7 492 goto out;
d24c33a4
JA
493 }
494 } while (1);
495
65864cf7 496out:
d1271dc1 497 global_write_unlock();
d24c33a4
JA
498 return NULL;
499}
500
501char *smalloc_strdup(const char *str)
502{
503 char *ptr;
504
505 ptr = smalloc(strlen(str) + 1);
506 strcpy(ptr, str);
507 return ptr;
508}