| 1 | /* |
| 2 | * Read a file and write the contents to stdout. If a given read takes |
| 3 | * longer than 'max_us' time, then we schedule a new thread to handle |
| 4 | * the next read. This avoids the coordinated omission problem, where |
| 5 | * one request appears to take a long time, but in reality a lot of |
| 6 | * requests would have been slow, but we don't notice since new submissions |
| 7 | * are not being issued if just 1 is held up. |
| 8 | * |
| 9 | * One test case: |
| 10 | * |
| 11 | * $ time (./read-to-pipe-async -f randfile.gz | gzip -dc > outfile; sync) |
| 12 | * |
| 13 | * This will read randfile.gz and log the latencies of doing so, while |
| 14 | * piping the output to gzip to decompress it. Any latencies over max_us |
| 15 | * are logged when they happen, and latency buckets are displayed at the |
| 16 | * end of the run |
| 17 | * |
| 18 | * gcc -Wall -g -O2 -o read-to-pipe-async read-to-pipe-async.c -lpthread |
| 19 | * |
| 20 | * Copyright (C) 2016 Jens Axboe |
| 21 | * |
| 22 | */ |
| 23 | |
| 24 | #include <stdio.h> |
| 25 | #include <stdlib.h> |
| 26 | #include <unistd.h> |
| 27 | #include <fcntl.h> |
| 28 | #include <sys/time.h> |
| 29 | #include <sys/types.h> |
| 30 | #include <sys/stat.h> |
| 31 | #include <inttypes.h> |
| 32 | #include <string.h> |
| 33 | #include <pthread.h> |
| 34 | #include <errno.h> |
| 35 | #include <assert.h> |
| 36 | |
| 37 | #include "../flist.h" |
| 38 | |
| 39 | static int bs = 4096; |
| 40 | static int max_us = 10000; |
| 41 | static char *file; |
| 42 | static int separate_writer = 1; |
| 43 | |
| 44 | #define PLAT_BITS 8 |
| 45 | #define PLAT_VAL (1 << PLAT_BITS) |
| 46 | #define PLAT_GROUP_NR 19 |
| 47 | #define PLAT_NR (PLAT_GROUP_NR * PLAT_VAL) |
| 48 | #define PLAT_LIST_MAX 20 |
| 49 | |
| 50 | struct stats { |
| 51 | unsigned int plat[PLAT_NR]; |
| 52 | unsigned int nr_samples; |
| 53 | unsigned int max; |
| 54 | unsigned int min; |
| 55 | unsigned int over; |
| 56 | }; |
| 57 | |
| 58 | static double plist[PLAT_LIST_MAX] = { 50.0, 75.0, 90.0, 95.0, 99.0, 99.5, 99.9, 99.99, 99.999, 99.9999, }; |
| 59 | |
| 60 | struct thread_data { |
| 61 | int exit; |
| 62 | int done; |
| 63 | pthread_mutex_t lock; |
| 64 | pthread_cond_t cond; |
| 65 | pthread_mutex_t done_lock; |
| 66 | pthread_cond_t done_cond; |
| 67 | pthread_t thread; |
| 68 | }; |
| 69 | |
| 70 | struct writer_thread { |
| 71 | struct flist_head list; |
| 72 | struct flist_head done_list; |
| 73 | struct stats s; |
| 74 | struct thread_data thread; |
| 75 | }; |
| 76 | |
| 77 | struct reader_thread { |
| 78 | struct flist_head list; |
| 79 | struct flist_head done_list; |
| 80 | int started; |
| 81 | int busy; |
| 82 | int write_seq; |
| 83 | struct stats s; |
| 84 | struct thread_data thread; |
| 85 | }; |
| 86 | |
| 87 | struct work_item { |
| 88 | struct flist_head list; |
| 89 | void *buf; |
| 90 | size_t buf_size; |
| 91 | off_t off; |
| 92 | int fd; |
| 93 | int seq; |
| 94 | struct writer_thread *writer; |
| 95 | struct reader_thread *reader; |
| 96 | pthread_mutex_t lock; |
| 97 | pthread_cond_t cond; |
| 98 | pthread_t thread; |
| 99 | }; |
| 100 | |
| 101 | static struct reader_thread reader_thread; |
| 102 | static struct writer_thread writer_thread; |
| 103 | |
| 104 | uint64_t utime_since(const struct timespec *s, const struct timespec *e) |
| 105 | { |
| 106 | long sec, usec; |
| 107 | uint64_t ret; |
| 108 | |
| 109 | sec = e->tv_sec - s->tv_sec; |
| 110 | usec = (e->tv_nsec - s->tv_nsec) / 1000; |
| 111 | if (sec > 0 && usec < 0) { |
| 112 | sec--; |
| 113 | usec += 1000000; |
| 114 | } |
| 115 | |
| 116 | if (sec < 0 || (sec == 0 && usec < 0)) |
| 117 | return 0; |
| 118 | |
| 119 | ret = sec * 1000000ULL + usec; |
| 120 | |
| 121 | return ret; |
| 122 | } |
| 123 | |
| 124 | static struct work_item *find_seq(struct writer_thread *w, unsigned int seq) |
| 125 | { |
| 126 | struct work_item *work; |
| 127 | struct flist_head *entry; |
| 128 | |
| 129 | if (flist_empty(&w->list)) |
| 130 | return NULL; |
| 131 | |
| 132 | flist_for_each(entry, &w->list) { |
| 133 | work = flist_entry(entry, struct work_item, list); |
| 134 | if (work->seq == seq) |
| 135 | return work; |
| 136 | } |
| 137 | |
| 138 | return NULL; |
| 139 | } |
| 140 | |
| 141 | static unsigned int plat_val_to_idx(unsigned int val) |
| 142 | { |
| 143 | unsigned int msb, error_bits, base, offset; |
| 144 | |
| 145 | /* Find MSB starting from bit 0 */ |
| 146 | if (val == 0) |
| 147 | msb = 0; |
| 148 | else |
| 149 | msb = sizeof(val)*8 - __builtin_clz(val) - 1; |
| 150 | |
| 151 | /* |
| 152 | * MSB <= (PLAT_BITS-1), cannot be rounded off. Use |
| 153 | * all bits of the sample as index |
| 154 | */ |
| 155 | if (msb <= PLAT_BITS) |
| 156 | return val; |
| 157 | |
| 158 | /* Compute the number of error bits to discard*/ |
| 159 | error_bits = msb - PLAT_BITS; |
| 160 | |
| 161 | /* Compute the number of buckets before the group */ |
| 162 | base = (error_bits + 1) << PLAT_BITS; |
| 163 | |
| 164 | /* |
| 165 | * Discard the error bits and apply the mask to find the |
| 166 | * index for the buckets in the group |
| 167 | */ |
| 168 | offset = (PLAT_VAL - 1) & (val >> error_bits); |
| 169 | |
| 170 | /* Make sure the index does not exceed (array size - 1) */ |
| 171 | return (base + offset) < (PLAT_NR - 1) ? |
| 172 | (base + offset) : (PLAT_NR - 1); |
| 173 | } |
| 174 | |
| 175 | /* |
| 176 | * Convert the given index of the bucket array to the value |
| 177 | * represented by the bucket |
| 178 | */ |
| 179 | static unsigned int plat_idx_to_val(unsigned int idx) |
| 180 | { |
| 181 | unsigned int error_bits, k, base; |
| 182 | |
| 183 | assert(idx < PLAT_NR); |
| 184 | |
| 185 | /* MSB <= (PLAT_BITS-1), cannot be rounded off. Use |
| 186 | * all bits of the sample as index */ |
| 187 | if (idx < (PLAT_VAL << 1)) |
| 188 | return idx; |
| 189 | |
| 190 | /* Find the group and compute the minimum value of that group */ |
| 191 | error_bits = (idx >> PLAT_BITS) - 1; |
| 192 | base = 1 << (error_bits + PLAT_BITS); |
| 193 | |
| 194 | /* Find its bucket number of the group */ |
| 195 | k = idx % PLAT_VAL; |
| 196 | |
| 197 | /* Return the mean of the range of the bucket */ |
| 198 | return base + ((k + 0.5) * (1 << error_bits)); |
| 199 | } |
| 200 | |
| 201 | static void add_lat(struct stats *s, unsigned int us, const char *name) |
| 202 | { |
| 203 | int lat_index = 0; |
| 204 | |
| 205 | if (us > s->max) |
| 206 | s->max = us; |
| 207 | if (us < s->min) |
| 208 | s->min = us; |
| 209 | |
| 210 | if (us > max_us) { |
| 211 | fprintf(stderr, "%s latency=%u usec\n", name, us); |
| 212 | s->over++; |
| 213 | } |
| 214 | |
| 215 | lat_index = plat_val_to_idx(us); |
| 216 | __sync_fetch_and_add(&s->plat[lat_index], 1); |
| 217 | __sync_fetch_and_add(&s->nr_samples, 1); |
| 218 | } |
| 219 | |
| 220 | static int write_work(struct work_item *work) |
| 221 | { |
| 222 | struct timespec s, e; |
| 223 | ssize_t ret; |
| 224 | |
| 225 | clock_gettime(CLOCK_MONOTONIC, &s); |
| 226 | ret = write(STDOUT_FILENO, work->buf, work->buf_size); |
| 227 | clock_gettime(CLOCK_MONOTONIC, &e); |
| 228 | assert(ret == work->buf_size); |
| 229 | |
| 230 | add_lat(&work->writer->s, utime_since(&s, &e), "write"); |
| 231 | return work->seq + 1; |
| 232 | } |
| 233 | |
| 234 | static void thread_exiting(struct thread_data *thread) |
| 235 | { |
| 236 | __sync_fetch_and_add(&thread->done, 1); |
| 237 | pthread_cond_signal(&thread->done_cond); |
| 238 | } |
| 239 | |
| 240 | static void *writer_fn(void *data) |
| 241 | { |
| 242 | struct writer_thread *wt = data; |
| 243 | struct work_item *work; |
| 244 | unsigned int seq = 1; |
| 245 | |
| 246 | work = NULL; |
| 247 | while (!wt->thread.exit || !flist_empty(&wt->list)) { |
| 248 | pthread_mutex_lock(&wt->thread.lock); |
| 249 | |
| 250 | if (work) { |
| 251 | flist_add_tail(&work->list, &wt->done_list); |
| 252 | work = NULL; |
| 253 | } |
| 254 | |
| 255 | work = find_seq(wt, seq); |
| 256 | if (work) |
| 257 | flist_del_init(&work->list); |
| 258 | else |
| 259 | pthread_cond_wait(&wt->thread.cond, &wt->thread.lock); |
| 260 | |
| 261 | pthread_mutex_unlock(&wt->thread.lock); |
| 262 | |
| 263 | if (work) |
| 264 | seq = write_work(work); |
| 265 | } |
| 266 | |
| 267 | thread_exiting(&wt->thread); |
| 268 | return NULL; |
| 269 | } |
| 270 | |
| 271 | static void reader_work(struct work_item *work) |
| 272 | { |
| 273 | struct timespec s, e; |
| 274 | ssize_t ret; |
| 275 | size_t left; |
| 276 | void *buf; |
| 277 | off_t off; |
| 278 | |
| 279 | clock_gettime(CLOCK_MONOTONIC, &s); |
| 280 | |
| 281 | left = work->buf_size; |
| 282 | buf = work->buf; |
| 283 | off = work->off; |
| 284 | while (left) { |
| 285 | ret = pread(work->fd, buf, left, off); |
| 286 | if (!ret) { |
| 287 | fprintf(stderr, "zero read\n"); |
| 288 | break; |
| 289 | } else if (ret < 0) { |
| 290 | fprintf(stderr, "errno=%d\n", errno); |
| 291 | break; |
| 292 | } |
| 293 | left -= ret; |
| 294 | off += ret; |
| 295 | buf += ret; |
| 296 | } |
| 297 | |
| 298 | clock_gettime(CLOCK_MONOTONIC, &e); |
| 299 | |
| 300 | add_lat(&work->reader->s, utime_since(&s, &e), "read"); |
| 301 | |
| 302 | pthread_cond_signal(&work->cond); |
| 303 | |
| 304 | if (separate_writer) { |
| 305 | pthread_mutex_lock(&work->writer->thread.lock); |
| 306 | flist_add_tail(&work->list, &work->writer->list); |
| 307 | pthread_mutex_unlock(&work->writer->thread.lock); |
| 308 | pthread_cond_signal(&work->writer->thread.cond); |
| 309 | } else { |
| 310 | struct reader_thread *rt = work->reader; |
| 311 | struct work_item *next = NULL; |
| 312 | struct flist_head *entry; |
| 313 | |
| 314 | /* |
| 315 | * Write current work if it matches in sequence. |
| 316 | */ |
| 317 | if (work->seq == rt->write_seq) |
| 318 | goto write_it; |
| 319 | |
| 320 | pthread_mutex_lock(&rt->thread.lock); |
| 321 | |
| 322 | flist_add_tail(&work->list, &rt->done_list); |
| 323 | |
| 324 | /* |
| 325 | * See if the next work item is here, if so, write it |
| 326 | */ |
| 327 | work = NULL; |
| 328 | flist_for_each(entry, &rt->done_list) { |
| 329 | next = flist_entry(entry, struct work_item, list); |
| 330 | if (next->seq == rt->write_seq) { |
| 331 | work = next; |
| 332 | flist_del(&work->list); |
| 333 | break; |
| 334 | } |
| 335 | } |
| 336 | |
| 337 | pthread_mutex_unlock(&rt->thread.lock); |
| 338 | |
| 339 | if (work) { |
| 340 | write_it: |
| 341 | write_work(work); |
| 342 | __sync_fetch_and_add(&rt->write_seq, 1); |
| 343 | } |
| 344 | } |
| 345 | } |
| 346 | |
| 347 | static void *reader_one_off(void *data) |
| 348 | { |
| 349 | reader_work(data); |
| 350 | return NULL; |
| 351 | } |
| 352 | |
| 353 | static void *reader_fn(void *data) |
| 354 | { |
| 355 | struct reader_thread *rt = data; |
| 356 | struct work_item *work; |
| 357 | |
| 358 | while (!rt->thread.exit || !flist_empty(&rt->list)) { |
| 359 | work = NULL; |
| 360 | pthread_mutex_lock(&rt->thread.lock); |
| 361 | if (!flist_empty(&rt->list)) { |
| 362 | work = flist_first_entry(&rt->list, struct work_item, list); |
| 363 | flist_del_init(&work->list); |
| 364 | } else |
| 365 | pthread_cond_wait(&rt->thread.cond, &rt->thread.lock); |
| 366 | pthread_mutex_unlock(&rt->thread.lock); |
| 367 | |
| 368 | if (work) { |
| 369 | __sync_fetch_and_add(&rt->busy, 1); |
| 370 | reader_work(work); |
| 371 | __sync_fetch_and_sub(&rt->busy, 1); |
| 372 | } |
| 373 | } |
| 374 | |
| 375 | thread_exiting(&rt->thread); |
| 376 | return NULL; |
| 377 | } |
| 378 | |
| 379 | static void queue_work(struct reader_thread *rt, struct work_item *work) |
| 380 | { |
| 381 | if (!rt->started) { |
| 382 | pthread_mutex_lock(&rt->thread.lock); |
| 383 | flist_add_tail(&work->list, &rt->list); |
| 384 | pthread_mutex_unlock(&rt->thread.lock); |
| 385 | |
| 386 | rt->started = 1; |
| 387 | pthread_create(&rt->thread.thread, NULL, reader_fn, rt); |
| 388 | } else if (!rt->busy && !pthread_mutex_trylock(&rt->thread.lock)) { |
| 389 | flist_add_tail(&work->list, &rt->list); |
| 390 | pthread_mutex_unlock(&rt->thread.lock); |
| 391 | |
| 392 | pthread_cond_signal(&rt->thread.cond); |
| 393 | } else { |
| 394 | int ret = pthread_create(&work->thread, NULL, reader_one_off, work); |
| 395 | if (ret) { |
| 396 | fprintf(stderr, "pthread_create=%d\n", ret); |
| 397 | } else { |
| 398 | ret = pthread_detach(work->thread); |
| 399 | if (ret) |
| 400 | fprintf(stderr, "pthread_detach=%d\n", ret); |
| 401 | } |
| 402 | } |
| 403 | } |
| 404 | |
| 405 | static unsigned int calc_percentiles(unsigned int *io_u_plat, unsigned long nr, |
| 406 | unsigned int **output) |
| 407 | { |
| 408 | unsigned long sum = 0; |
| 409 | unsigned int len, i, j = 0; |
| 410 | unsigned int oval_len = 0; |
| 411 | unsigned int *ovals = NULL; |
| 412 | int is_last; |
| 413 | |
| 414 | len = 0; |
| 415 | while (len < PLAT_LIST_MAX && plist[len] != 0.0) |
| 416 | len++; |
| 417 | |
| 418 | if (!len) |
| 419 | return 0; |
| 420 | |
| 421 | /* |
| 422 | * Calculate bucket values, note down max and min values |
| 423 | */ |
| 424 | is_last = 0; |
| 425 | for (i = 0; i < PLAT_NR && !is_last; i++) { |
| 426 | sum += io_u_plat[i]; |
| 427 | while (sum >= (plist[j] / 100.0 * nr)) { |
| 428 | assert(plist[j] <= 100.0); |
| 429 | |
| 430 | if (j == oval_len) { |
| 431 | oval_len += 100; |
| 432 | ovals = realloc(ovals, oval_len * sizeof(unsigned int)); |
| 433 | } |
| 434 | |
| 435 | ovals[j] = plat_idx_to_val(i); |
| 436 | is_last = (j == len - 1); |
| 437 | if (is_last) |
| 438 | break; |
| 439 | |
| 440 | j++; |
| 441 | } |
| 442 | } |
| 443 | |
| 444 | *output = ovals; |
| 445 | return len; |
| 446 | } |
| 447 | |
| 448 | static void show_latencies(struct stats *s, const char *msg) |
| 449 | { |
| 450 | unsigned int *ovals = NULL; |
| 451 | unsigned int len, i; |
| 452 | |
| 453 | len = calc_percentiles(s->plat, s->nr_samples, &ovals); |
| 454 | if (len) { |
| 455 | fprintf(stderr, "Latency percentiles (usec) (%s)\n", msg); |
| 456 | for (i = 0; i < len; i++) |
| 457 | fprintf(stderr, "\t%2.4fth: %u\n", plist[i], ovals[i]); |
| 458 | } |
| 459 | |
| 460 | if (ovals) |
| 461 | free(ovals); |
| 462 | |
| 463 | fprintf(stderr, "\tOver=%u, min=%u, max=%u\n", s->over, s->min, s->max); |
| 464 | } |
| 465 | |
| 466 | static void init_thread(struct thread_data *thread) |
| 467 | { |
| 468 | pthread_condattr_t cattr; |
| 469 | int ret; |
| 470 | |
| 471 | ret = pthread_condattr_init(&cattr); |
| 472 | assert(ret == 0); |
| 473 | #ifdef CONFIG_PTHREAD_CONDATTR_SETCLOCK |
| 474 | ret = pthread_condattr_setclock(&cattr, CLOCK_MONOTONIC); |
| 475 | assert(ret == 0); |
| 476 | #endif |
| 477 | pthread_cond_init(&thread->cond, &cattr); |
| 478 | pthread_cond_init(&thread->done_cond, &cattr); |
| 479 | pthread_mutex_init(&thread->lock, NULL); |
| 480 | pthread_mutex_init(&thread->done_lock, NULL); |
| 481 | thread->exit = 0; |
| 482 | } |
| 483 | |
| 484 | static void exit_thread(struct thread_data *thread, |
| 485 | void fn(struct writer_thread *), |
| 486 | struct writer_thread *wt) |
| 487 | { |
| 488 | __sync_fetch_and_add(&thread->exit, 1); |
| 489 | pthread_cond_signal(&thread->cond); |
| 490 | |
| 491 | while (!thread->done) { |
| 492 | pthread_mutex_lock(&thread->done_lock); |
| 493 | |
| 494 | if (fn) { |
| 495 | struct timespec ts; |
| 496 | |
| 497 | #ifdef CONFIG_PTHREAD_CONDATTR_SETCLOCK |
| 498 | clock_gettime(CLOCK_MONOTONIC, &ts); |
| 499 | #else |
| 500 | clock_gettime(CLOCK_REALTIME, &ts); |
| 501 | #endif |
| 502 | ts.tv_sec++; |
| 503 | |
| 504 | pthread_cond_timedwait(&thread->done_cond, &thread->done_lock, &ts); |
| 505 | fn(wt); |
| 506 | } else |
| 507 | pthread_cond_wait(&thread->done_cond, &thread->done_lock); |
| 508 | |
| 509 | pthread_mutex_unlock(&thread->done_lock); |
| 510 | } |
| 511 | } |
| 512 | |
| 513 | static int usage(char *argv[]) |
| 514 | { |
| 515 | fprintf(stderr, "%s: [-b blocksize] [-t max usec] [-w separate writer] -f file\n", argv[0]); |
| 516 | return 1; |
| 517 | } |
| 518 | |
| 519 | static int parse_options(int argc, char *argv[]) |
| 520 | { |
| 521 | int c; |
| 522 | |
| 523 | while ((c = getopt(argc, argv, "f:b:t:w:")) != -1) { |
| 524 | switch (c) { |
| 525 | case 'f': |
| 526 | if (file) |
| 527 | return usage(argv); |
| 528 | file = strdup(optarg); |
| 529 | break; |
| 530 | case 'b': |
| 531 | bs = atoi(optarg); |
| 532 | break; |
| 533 | case 't': |
| 534 | max_us = atoi(optarg); |
| 535 | break; |
| 536 | case 'w': |
| 537 | separate_writer = atoi(optarg); |
| 538 | if (!separate_writer) |
| 539 | fprintf(stderr, "inline writing is broken\n"); |
| 540 | break; |
| 541 | case '?': |
| 542 | default: |
| 543 | return usage(argv); |
| 544 | } |
| 545 | } |
| 546 | |
| 547 | if (!file) |
| 548 | return usage(argv); |
| 549 | |
| 550 | return 0; |
| 551 | } |
| 552 | |
| 553 | static void prune_done_entries(struct writer_thread *wt) |
| 554 | { |
| 555 | FLIST_HEAD(list); |
| 556 | |
| 557 | if (flist_empty(&wt->done_list)) |
| 558 | return; |
| 559 | |
| 560 | if (pthread_mutex_trylock(&wt->thread.lock)) |
| 561 | return; |
| 562 | |
| 563 | if (!flist_empty(&wt->done_list)) |
| 564 | flist_splice_init(&wt->done_list, &list); |
| 565 | pthread_mutex_unlock(&wt->thread.lock); |
| 566 | |
| 567 | while (!flist_empty(&list)) { |
| 568 | struct work_item *work; |
| 569 | |
| 570 | work = flist_first_entry(&list, struct work_item, list); |
| 571 | flist_del(&work->list); |
| 572 | |
| 573 | pthread_cond_destroy(&work->cond); |
| 574 | pthread_mutex_destroy(&work->lock); |
| 575 | free(work->buf); |
| 576 | free(work); |
| 577 | } |
| 578 | } |
| 579 | |
| 580 | int main(int argc, char *argv[]) |
| 581 | { |
| 582 | pthread_condattr_t cattr; |
| 583 | struct timespec s, re, we; |
| 584 | struct reader_thread *rt; |
| 585 | struct writer_thread *wt; |
| 586 | unsigned long rate; |
| 587 | uint64_t elapsed; |
| 588 | struct stat sb; |
| 589 | size_t bytes; |
| 590 | off_t off; |
| 591 | int fd, seq; |
| 592 | int ret; |
| 593 | |
| 594 | if (parse_options(argc, argv)) |
| 595 | return 1; |
| 596 | |
| 597 | fd = open(file, O_RDONLY); |
| 598 | if (fd < 0) { |
| 599 | perror("open"); |
| 600 | return 2; |
| 601 | } |
| 602 | |
| 603 | if (fstat(fd, &sb) < 0) { |
| 604 | perror("stat"); |
| 605 | return 3; |
| 606 | } |
| 607 | |
| 608 | wt = &writer_thread; |
| 609 | init_thread(&wt->thread); |
| 610 | INIT_FLIST_HEAD(&wt->list); |
| 611 | INIT_FLIST_HEAD(&wt->done_list); |
| 612 | wt->s.max = 0; |
| 613 | wt->s.min = -1U; |
| 614 | pthread_create(&wt->thread.thread, NULL, writer_fn, wt); |
| 615 | |
| 616 | rt = &reader_thread; |
| 617 | init_thread(&rt->thread); |
| 618 | INIT_FLIST_HEAD(&rt->list); |
| 619 | INIT_FLIST_HEAD(&rt->done_list); |
| 620 | rt->s.max = 0; |
| 621 | rt->s.min = -1U; |
| 622 | rt->write_seq = 1; |
| 623 | |
| 624 | off = 0; |
| 625 | seq = 0; |
| 626 | bytes = 0; |
| 627 | |
| 628 | ret = pthread_condattr_init(&cattr); |
| 629 | assert(ret == 0); |
| 630 | #ifdef CONFIG_PTHREAD_CONDATTR_SETCLOCK |
| 631 | ret = pthread_condattr_setclock(&cattr, CLOCK_MONOTONIC); |
| 632 | assert(ret == 0); |
| 633 | #endif |
| 634 | |
| 635 | clock_gettime(CLOCK_MONOTONIC, &s); |
| 636 | |
| 637 | while (sb.st_size) { |
| 638 | struct work_item *work; |
| 639 | size_t this_len; |
| 640 | struct timespec ts; |
| 641 | |
| 642 | prune_done_entries(wt); |
| 643 | |
| 644 | this_len = sb.st_size; |
| 645 | if (this_len > bs) |
| 646 | this_len = bs; |
| 647 | |
| 648 | work = calloc(1, sizeof(*work)); |
| 649 | work->buf = malloc(this_len); |
| 650 | work->buf_size = this_len; |
| 651 | work->off = off; |
| 652 | work->fd = fd; |
| 653 | work->seq = ++seq; |
| 654 | work->writer = wt; |
| 655 | work->reader = rt; |
| 656 | pthread_cond_init(&work->cond, &cattr); |
| 657 | pthread_mutex_init(&work->lock, NULL); |
| 658 | |
| 659 | queue_work(rt, work); |
| 660 | |
| 661 | #ifdef CONFIG_PTHREAD_CONDATTR_SETCLOCK |
| 662 | clock_gettime(CLOCK_MONOTONIC, &ts); |
| 663 | #else |
| 664 | clock_gettime(CLOCK_REALTIME, &ts); |
| 665 | #endif |
| 666 | ts.tv_nsec += max_us * 1000ULL; |
| 667 | if (ts.tv_nsec >= 1000000000ULL) { |
| 668 | ts.tv_nsec -= 1000000000ULL; |
| 669 | ts.tv_sec++; |
| 670 | } |
| 671 | |
| 672 | pthread_mutex_lock(&work->lock); |
| 673 | pthread_cond_timedwait(&work->cond, &work->lock, &ts); |
| 674 | pthread_mutex_unlock(&work->lock); |
| 675 | |
| 676 | off += this_len; |
| 677 | sb.st_size -= this_len; |
| 678 | bytes += this_len; |
| 679 | } |
| 680 | |
| 681 | exit_thread(&rt->thread, NULL, NULL); |
| 682 | clock_gettime(CLOCK_MONOTONIC, &re); |
| 683 | |
| 684 | exit_thread(&wt->thread, prune_done_entries, wt); |
| 685 | clock_gettime(CLOCK_MONOTONIC, &we); |
| 686 | |
| 687 | show_latencies(&rt->s, "READERS"); |
| 688 | show_latencies(&wt->s, "WRITERS"); |
| 689 | |
| 690 | bytes /= 1024; |
| 691 | elapsed = utime_since(&s, &re); |
| 692 | rate = elapsed ? (bytes * 1000UL * 1000UL) / elapsed : 0; |
| 693 | fprintf(stderr, "Read rate (KiB/sec) : %lu\n", rate); |
| 694 | elapsed = utime_since(&s, &we); |
| 695 | rate = elapsed ? (bytes * 1000UL * 1000UL) / elapsed : 0; |
| 696 | fprintf(stderr, "Write rate (KiB/sec): %lu\n", rate); |
| 697 | |
| 698 | close(fd); |
| 699 | return 0; |
| 700 | } |