1 /* 2 * Copyright (C) 2011, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com> 3 * 4 * Parts came from builtin-{top,stat,record}.c, see those files for further 5 * copyright notes. 6 * 7 * Released under the GPL v2. (and only v2, not any later version) 8 */ 9 #include "util.h" 10 #include "debugfs.h" 11 #include <poll.h> 12 #include "cpumap.h" 13 #include "thread_map.h" 14 #include "evlist.h" 15 #include "evsel.h" 16 #include <unistd.h> 17 18 #include "parse-events.h" 19 20 #include <sys/mman.h> 21 22 #include <linux/bitops.h> 23 #include <linux/hash.h> 24 25 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y)) 26 #define SID(e, x, y) xyarray__entry(e->sample_id, x, y) 27 28 void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus, 29 struct thread_map *threads) 30 { 31 int i; 32 33 for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i) 34 INIT_HLIST_HEAD(&evlist->heads[i]); 35 INIT_LIST_HEAD(&evlist->entries); 36 perf_evlist__set_maps(evlist, cpus, threads); 37 evlist->workload.pid = -1; 38 } 39 40 struct perf_evlist *perf_evlist__new(struct cpu_map *cpus, 41 struct thread_map *threads) 42 { 43 struct perf_evlist *evlist = zalloc(sizeof(*evlist)); 44 45 if (evlist != NULL) 46 perf_evlist__init(evlist, cpus, threads); 47 48 return evlist; 49 } 50 51 void perf_evlist__config_attrs(struct perf_evlist *evlist, 52 struct perf_record_opts *opts) 53 { 54 struct perf_evsel *evsel; 55 56 if (evlist->cpus->map[0] < 0) 57 opts->no_inherit = true; 58 59 list_for_each_entry(evsel, &evlist->entries, node) { 60 perf_evsel__config(evsel, opts); 61 62 if (evlist->nr_entries > 1) 63 evsel->attr.sample_type |= PERF_SAMPLE_ID; 64 } 65 } 66 67 static void perf_evlist__purge(struct perf_evlist *evlist) 68 { 69 struct perf_evsel *pos, *n; 70 71 list_for_each_entry_safe(pos, n, &evlist->entries, node) { 72 list_del_init(&pos->node); 73 perf_evsel__delete(pos); 74 } 75 76 evlist->nr_entries = 0; 77 } 78 79 void perf_evlist__exit(struct perf_evlist *evlist) 80 { 81 free(evlist->mmap); 82 free(evlist->pollfd); 83 evlist->mmap = NULL; 84 evlist->pollfd = NULL; 85 } 86 87 void perf_evlist__delete(struct perf_evlist *evlist) 88 { 89 perf_evlist__purge(evlist); 90 perf_evlist__exit(evlist); 91 free(evlist); 92 } 93 94 void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry) 95 { 96 list_add_tail(&entry->node, &evlist->entries); 97 ++evlist->nr_entries; 98 } 99 100 static void perf_evlist__splice_list_tail(struct perf_evlist *evlist, 101 struct list_head *list, 102 int nr_entries) 103 { 104 list_splice_tail(list, &evlist->entries); 105 evlist->nr_entries += nr_entries; 106 } 107 108 int perf_evlist__add_default(struct perf_evlist *evlist) 109 { 110 struct perf_event_attr attr = { 111 .type = PERF_TYPE_HARDWARE, 112 .config = PERF_COUNT_HW_CPU_CYCLES, 113 }; 114 struct perf_evsel *evsel = perf_evsel__new(&attr, 0); 115 116 if (evsel == NULL) 117 goto error; 118 119 /* use strdup() because free(evsel) assumes name is allocated */ 120 evsel->name = strdup("cycles"); 121 if (!evsel->name) 122 goto error_free; 123 124 perf_evlist__add(evlist, evsel); 125 return 0; 126 error_free: 127 perf_evsel__delete(evsel); 128 error: 129 return -ENOMEM; 130 } 131 132 int perf_evlist__add_attrs(struct perf_evlist *evlist, 133 struct perf_event_attr *attrs, size_t nr_attrs) 134 { 135 struct perf_evsel *evsel, *n; 136 LIST_HEAD(head); 137 size_t i; 138 139 for (i = 0; i < nr_attrs; i++) { 140 evsel = perf_evsel__new(attrs + i, evlist->nr_entries + i); 141 if (evsel == NULL) 142 goto out_delete_partial_list; 143 list_add_tail(&evsel->node, &head); 144 } 145 146 perf_evlist__splice_list_tail(evlist, &head, nr_attrs); 147 148 return 0; 149 150 out_delete_partial_list: 151 list_for_each_entry_safe(evsel, n, &head, node) 152 perf_evsel__delete(evsel); 153 return -1; 154 } 155 156 static int trace_event__id(const char *evname) 157 { 158 char *filename, *colon; 159 int err = -1, fd; 160 161 if (asprintf(&filename, "%s/%s/id", tracing_events_path, evname) < 0) 162 return -1; 163 164 colon = strrchr(filename, ':'); 165 if (colon != NULL) 166 *colon = '/'; 167 168 fd = open(filename, O_RDONLY); 169 if (fd >= 0) { 170 char id[16]; 171 if (read(fd, id, sizeof(id)) > 0) 172 err = atoi(id); 173 close(fd); 174 } 175 176 free(filename); 177 return err; 178 } 179 180 int perf_evlist__add_tracepoints(struct perf_evlist *evlist, 181 const char *tracepoints[], 182 size_t nr_tracepoints) 183 { 184 int err; 185 size_t i; 186 struct perf_event_attr *attrs = zalloc(nr_tracepoints * sizeof(*attrs)); 187 188 if (attrs == NULL) 189 return -1; 190 191 for (i = 0; i < nr_tracepoints; i++) { 192 err = trace_event__id(tracepoints[i]); 193 194 if (err < 0) 195 goto out_free_attrs; 196 197 attrs[i].type = PERF_TYPE_TRACEPOINT; 198 attrs[i].config = err; 199 attrs[i].sample_type = (PERF_SAMPLE_RAW | PERF_SAMPLE_TIME | 200 PERF_SAMPLE_CPU); 201 attrs[i].sample_period = 1; 202 } 203 204 err = perf_evlist__add_attrs(evlist, attrs, nr_tracepoints); 205 out_free_attrs: 206 free(attrs); 207 return err; 208 } 209 210 static struct perf_evsel * 211 perf_evlist__find_tracepoint_by_id(struct perf_evlist *evlist, int id) 212 { 213 struct perf_evsel *evsel; 214 215 list_for_each_entry(evsel, &evlist->entries, node) { 216 if (evsel->attr.type == PERF_TYPE_TRACEPOINT && 217 (int)evsel->attr.config == id) 218 return evsel; 219 } 220 221 return NULL; 222 } 223 224 int perf_evlist__set_tracepoints_handlers(struct perf_evlist *evlist, 225 const struct perf_evsel_str_handler *assocs, 226 size_t nr_assocs) 227 { 228 struct perf_evsel *evsel; 229 int err; 230 size_t i; 231 232 for (i = 0; i < nr_assocs; i++) { 233 err = trace_event__id(assocs[i].name); 234 if (err < 0) 235 goto out; 236 237 evsel = perf_evlist__find_tracepoint_by_id(evlist, err); 238 if (evsel == NULL) 239 continue; 240 241 err = -EEXIST; 242 if (evsel->handler.func != NULL) 243 goto out; 244 evsel->handler.func = assocs[i].handler; 245 } 246 247 err = 0; 248 out: 249 return err; 250 } 251 252 void perf_evlist__disable(struct perf_evlist *evlist) 253 { 254 int cpu, thread; 255 struct perf_evsel *pos; 256 257 for (cpu = 0; cpu < evlist->cpus->nr; cpu++) { 258 list_for_each_entry(pos, &evlist->entries, node) { 259 for (thread = 0; thread < evlist->threads->nr; thread++) 260 ioctl(FD(pos, cpu, thread), PERF_EVENT_IOC_DISABLE); 261 } 262 } 263 } 264 265 void perf_evlist__enable(struct perf_evlist *evlist) 266 { 267 int cpu, thread; 268 struct perf_evsel *pos; 269 270 for (cpu = 0; cpu < evlist->cpus->nr; cpu++) { 271 list_for_each_entry(pos, &evlist->entries, node) { 272 for (thread = 0; thread < evlist->threads->nr; thread++) 273 ioctl(FD(pos, cpu, thread), PERF_EVENT_IOC_ENABLE); 274 } 275 } 276 } 277 278 static int perf_evlist__alloc_pollfd(struct perf_evlist *evlist) 279 { 280 int nfds = evlist->cpus->nr * evlist->threads->nr * evlist->nr_entries; 281 evlist->pollfd = malloc(sizeof(struct pollfd) * nfds); 282 return evlist->pollfd != NULL ? 0 : -ENOMEM; 283 } 284 285 void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd) 286 { 287 fcntl(fd, F_SETFL, O_NONBLOCK); 288 evlist->pollfd[evlist->nr_fds].fd = fd; 289 evlist->pollfd[evlist->nr_fds].events = POLLIN; 290 evlist->nr_fds++; 291 } 292 293 static void perf_evlist__id_hash(struct perf_evlist *evlist, 294 struct perf_evsel *evsel, 295 int cpu, int thread, u64 id) 296 { 297 int hash; 298 struct perf_sample_id *sid = SID(evsel, cpu, thread); 299 300 sid->id = id; 301 sid->evsel = evsel; 302 hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS); 303 hlist_add_head(&sid->node, &evlist->heads[hash]); 304 } 305 306 void perf_evlist__id_add(struct perf_evlist *evlist, struct perf_evsel *evsel, 307 int cpu, int thread, u64 id) 308 { 309 perf_evlist__id_hash(evlist, evsel, cpu, thread, id); 310 evsel->id[evsel->ids++] = id; 311 } 312 313 static int perf_evlist__id_add_fd(struct perf_evlist *evlist, 314 struct perf_evsel *evsel, 315 int cpu, int thread, int fd) 316 { 317 u64 read_data[4] = { 0, }; 318 int id_idx = 1; /* The first entry is the counter value */ 319 320 if (!(evsel->attr.read_format & PERF_FORMAT_ID) || 321 read(fd, &read_data, sizeof(read_data)) == -1) 322 return -1; 323 324 if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED) 325 ++id_idx; 326 if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING) 327 ++id_idx; 328 329 perf_evlist__id_add(evlist, evsel, cpu, thread, read_data[id_idx]); 330 return 0; 331 } 332 333 struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id) 334 { 335 struct hlist_head *head; 336 struct hlist_node *pos; 337 struct perf_sample_id *sid; 338 int hash; 339 340 if (evlist->nr_entries == 1) 341 return list_entry(evlist->entries.next, struct perf_evsel, node); 342 343 hash = hash_64(id, PERF_EVLIST__HLIST_BITS); 344 head = &evlist->heads[hash]; 345 346 hlist_for_each_entry(sid, pos, head, node) 347 if (sid->id == id) 348 return sid->evsel; 349 return NULL; 350 } 351 352 union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx) 353 { 354 /* XXX Move this to perf.c, making it generally available */ 355 unsigned int page_size = sysconf(_SC_PAGE_SIZE); 356 struct perf_mmap *md = &evlist->mmap[idx]; 357 unsigned int head = perf_mmap__read_head(md); 358 unsigned int old = md->prev; 359 unsigned char *data = md->base + page_size; 360 union perf_event *event = NULL; 361 362 if (evlist->overwrite) { 363 /* 364 * If we're further behind than half the buffer, there's a chance 365 * the writer will bite our tail and mess up the samples under us. 366 * 367 * If we somehow ended up ahead of the head, we got messed up. 368 * 369 * In either case, truncate and restart at head. 370 */ 371 int diff = head - old; 372 if (diff > md->mask / 2 || diff < 0) { 373 fprintf(stderr, "WARNING: failed to keep up with mmap data.\n"); 374 375 /* 376 * head points to a known good entry, start there. 377 */ 378 old = head; 379 } 380 } 381 382 if (old != head) { 383 size_t size; 384 385 event = (union perf_event *)&data[old & md->mask]; 386 size = event->header.size; 387 388 /* 389 * Event straddles the mmap boundary -- header should always 390 * be inside due to u64 alignment of output. 391 */ 392 if ((old & md->mask) + size != ((old + size) & md->mask)) { 393 unsigned int offset = old; 394 unsigned int len = min(sizeof(*event), size), cpy; 395 void *dst = &evlist->event_copy; 396 397 do { 398 cpy = min(md->mask + 1 - (offset & md->mask), len); 399 memcpy(dst, &data[offset & md->mask], cpy); 400 offset += cpy; 401 dst += cpy; 402 len -= cpy; 403 } while (len); 404 405 event = &evlist->event_copy; 406 } 407 408 old += size; 409 } 410 411 md->prev = old; 412 413 if (!evlist->overwrite) 414 perf_mmap__write_tail(md, old); 415 416 return event; 417 } 418 419 void perf_evlist__munmap(struct perf_evlist *evlist) 420 { 421 int i; 422 423 for (i = 0; i < evlist->nr_mmaps; i++) { 424 if (evlist->mmap[i].base != NULL) { 425 munmap(evlist->mmap[i].base, evlist->mmap_len); 426 evlist->mmap[i].base = NULL; 427 } 428 } 429 430 free(evlist->mmap); 431 evlist->mmap = NULL; 432 } 433 434 static int perf_evlist__alloc_mmap(struct perf_evlist *evlist) 435 { 436 evlist->nr_mmaps = evlist->cpus->nr; 437 if (evlist->cpus->map[0] == -1) 438 evlist->nr_mmaps = evlist->threads->nr; 439 evlist->mmap = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap)); 440 return evlist->mmap != NULL ? 0 : -ENOMEM; 441 } 442 443 static int __perf_evlist__mmap(struct perf_evlist *evlist, 444 int idx, int prot, int mask, int fd) 445 { 446 evlist->mmap[idx].prev = 0; 447 evlist->mmap[idx].mask = mask; 448 evlist->mmap[idx].base = mmap(NULL, evlist->mmap_len, prot, 449 MAP_SHARED, fd, 0); 450 if (evlist->mmap[idx].base == MAP_FAILED) { 451 evlist->mmap[idx].base = NULL; 452 return -1; 453 } 454 455 perf_evlist__add_pollfd(evlist, fd); 456 return 0; 457 } 458 459 static int perf_evlist__mmap_per_cpu(struct perf_evlist *evlist, int prot, int mask) 460 { 461 struct perf_evsel *evsel; 462 int cpu, thread; 463 464 for (cpu = 0; cpu < evlist->cpus->nr; cpu++) { 465 int output = -1; 466 467 for (thread = 0; thread < evlist->threads->nr; thread++) { 468 list_for_each_entry(evsel, &evlist->entries, node) { 469 int fd = FD(evsel, cpu, thread); 470 471 if (output == -1) { 472 output = fd; 473 if (__perf_evlist__mmap(evlist, cpu, 474 prot, mask, output) < 0) 475 goto out_unmap; 476 } else { 477 if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, output) != 0) 478 goto out_unmap; 479 } 480 481 if ((evsel->attr.read_format & PERF_FORMAT_ID) && 482 perf_evlist__id_add_fd(evlist, evsel, cpu, thread, fd) < 0) 483 goto out_unmap; 484 } 485 } 486 } 487 488 return 0; 489 490 out_unmap: 491 for (cpu = 0; cpu < evlist->cpus->nr; cpu++) { 492 if (evlist->mmap[cpu].base != NULL) { 493 munmap(evlist->mmap[cpu].base, evlist->mmap_len); 494 evlist->mmap[cpu].base = NULL; 495 } 496 } 497 return -1; 498 } 499 500 static int perf_evlist__mmap_per_thread(struct perf_evlist *evlist, int prot, int mask) 501 { 502 struct perf_evsel *evsel; 503 int thread; 504 505 for (thread = 0; thread < evlist->threads->nr; thread++) { 506 int output = -1; 507 508 list_for_each_entry(evsel, &evlist->entries, node) { 509 int fd = FD(evsel, 0, thread); 510 511 if (output == -1) { 512 output = fd; 513 if (__perf_evlist__mmap(evlist, thread, 514 prot, mask, output) < 0) 515 goto out_unmap; 516 } else { 517 if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, output) != 0) 518 goto out_unmap; 519 } 520 521 if ((evsel->attr.read_format & PERF_FORMAT_ID) && 522 perf_evlist__id_add_fd(evlist, evsel, 0, thread, fd) < 0) 523 goto out_unmap; 524 } 525 } 526 527 return 0; 528 529 out_unmap: 530 for (thread = 0; thread < evlist->threads->nr; thread++) { 531 if (evlist->mmap[thread].base != NULL) { 532 munmap(evlist->mmap[thread].base, evlist->mmap_len); 533 evlist->mmap[thread].base = NULL; 534 } 535 } 536 return -1; 537 } 538 539 /** perf_evlist__mmap - Create per cpu maps to receive events 540 * 541 * @evlist - list of events 542 * @pages - map length in pages 543 * @overwrite - overwrite older events? 544 * 545 * If overwrite is false the user needs to signal event consuption using: 546 * 547 * struct perf_mmap *m = &evlist->mmap[cpu]; 548 * unsigned int head = perf_mmap__read_head(m); 549 * 550 * perf_mmap__write_tail(m, head) 551 * 552 * Using perf_evlist__read_on_cpu does this automatically. 553 */ 554 int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages, 555 bool overwrite) 556 { 557 unsigned int page_size = sysconf(_SC_PAGE_SIZE); 558 struct perf_evsel *evsel; 559 const struct cpu_map *cpus = evlist->cpus; 560 const struct thread_map *threads = evlist->threads; 561 int prot = PROT_READ | (overwrite ? 0 : PROT_WRITE), mask; 562 563 /* 512 kiB: default amount of unprivileged mlocked memory */ 564 if (pages == UINT_MAX) 565 pages = (512 * 1024) / page_size; 566 else if (!is_power_of_2(pages)) 567 return -EINVAL; 568 569 mask = pages * page_size - 1; 570 571 if (evlist->mmap == NULL && perf_evlist__alloc_mmap(evlist) < 0) 572 return -ENOMEM; 573 574 if (evlist->pollfd == NULL && perf_evlist__alloc_pollfd(evlist) < 0) 575 return -ENOMEM; 576 577 evlist->overwrite = overwrite; 578 evlist->mmap_len = (pages + 1) * page_size; 579 580 list_for_each_entry(evsel, &evlist->entries, node) { 581 if ((evsel->attr.read_format & PERF_FORMAT_ID) && 582 evsel->sample_id == NULL && 583 perf_evsel__alloc_id(evsel, cpus->nr, threads->nr) < 0) 584 return -ENOMEM; 585 } 586 587 if (evlist->cpus->map[0] == -1) 588 return perf_evlist__mmap_per_thread(evlist, prot, mask); 589 590 return perf_evlist__mmap_per_cpu(evlist, prot, mask); 591 } 592 593 int perf_evlist__create_maps(struct perf_evlist *evlist, pid_t target_pid, 594 pid_t target_tid, const char *cpu_list) 595 { 596 evlist->threads = thread_map__new(target_pid, target_tid); 597 598 if (evlist->threads == NULL) 599 return -1; 600 601 if (cpu_list == NULL && target_tid != -1) 602 evlist->cpus = cpu_map__dummy_new(); 603 else 604 evlist->cpus = cpu_map__new(cpu_list); 605 606 if (evlist->cpus == NULL) 607 goto out_delete_threads; 608 609 return 0; 610 611 out_delete_threads: 612 thread_map__delete(evlist->threads); 613 return -1; 614 } 615 616 void perf_evlist__delete_maps(struct perf_evlist *evlist) 617 { 618 cpu_map__delete(evlist->cpus); 619 thread_map__delete(evlist->threads); 620 evlist->cpus = NULL; 621 evlist->threads = NULL; 622 } 623 624 int perf_evlist__set_filters(struct perf_evlist *evlist) 625 { 626 const struct thread_map *threads = evlist->threads; 627 const struct cpu_map *cpus = evlist->cpus; 628 struct perf_evsel *evsel; 629 char *filter; 630 int thread; 631 int cpu; 632 int err; 633 int fd; 634 635 list_for_each_entry(evsel, &evlist->entries, node) { 636 filter = evsel->filter; 637 if (!filter) 638 continue; 639 for (cpu = 0; cpu < cpus->nr; cpu++) { 640 for (thread = 0; thread < threads->nr; thread++) { 641 fd = FD(evsel, cpu, thread); 642 err = ioctl(fd, PERF_EVENT_IOC_SET_FILTER, filter); 643 if (err) 644 return err; 645 } 646 } 647 } 648 649 return 0; 650 } 651 652 bool perf_evlist__valid_sample_type(const struct perf_evlist *evlist) 653 { 654 struct perf_evsel *pos, *first; 655 656 pos = first = list_entry(evlist->entries.next, struct perf_evsel, node); 657 658 list_for_each_entry_continue(pos, &evlist->entries, node) { 659 if (first->attr.sample_type != pos->attr.sample_type) 660 return false; 661 } 662 663 return true; 664 } 665 666 u64 perf_evlist__sample_type(const struct perf_evlist *evlist) 667 { 668 struct perf_evsel *first; 669 670 first = list_entry(evlist->entries.next, struct perf_evsel, node); 671 return first->attr.sample_type; 672 } 673 674 u16 perf_evlist__id_hdr_size(const struct perf_evlist *evlist) 675 { 676 struct perf_evsel *first; 677 struct perf_sample *data; 678 u64 sample_type; 679 u16 size = 0; 680 681 first = list_entry(evlist->entries.next, struct perf_evsel, node); 682 683 if (!first->attr.sample_id_all) 684 goto out; 685 686 sample_type = first->attr.sample_type; 687 688 if (sample_type & PERF_SAMPLE_TID) 689 size += sizeof(data->tid) * 2; 690 691 if (sample_type & PERF_SAMPLE_TIME) 692 size += sizeof(data->time); 693 694 if (sample_type & PERF_SAMPLE_ID) 695 size += sizeof(data->id); 696 697 if (sample_type & PERF_SAMPLE_STREAM_ID) 698 size += sizeof(data->stream_id); 699 700 if (sample_type & PERF_SAMPLE_CPU) 701 size += sizeof(data->cpu) * 2; 702 out: 703 return size; 704 } 705 706 bool perf_evlist__valid_sample_id_all(const struct perf_evlist *evlist) 707 { 708 struct perf_evsel *pos, *first; 709 710 pos = first = list_entry(evlist->entries.next, struct perf_evsel, node); 711 712 list_for_each_entry_continue(pos, &evlist->entries, node) { 713 if (first->attr.sample_id_all != pos->attr.sample_id_all) 714 return false; 715 } 716 717 return true; 718 } 719 720 bool perf_evlist__sample_id_all(const struct perf_evlist *evlist) 721 { 722 struct perf_evsel *first; 723 724 first = list_entry(evlist->entries.next, struct perf_evsel, node); 725 return first->attr.sample_id_all; 726 } 727 728 void perf_evlist__set_selected(struct perf_evlist *evlist, 729 struct perf_evsel *evsel) 730 { 731 evlist->selected = evsel; 732 } 733 734 int perf_evlist__open(struct perf_evlist *evlist, bool group) 735 { 736 struct perf_evsel *evsel, *first; 737 int err, ncpus, nthreads; 738 739 first = list_entry(evlist->entries.next, struct perf_evsel, node); 740 741 list_for_each_entry(evsel, &evlist->entries, node) { 742 struct xyarray *group_fd = NULL; 743 744 if (group && evsel != first) 745 group_fd = first->fd; 746 747 err = perf_evsel__open(evsel, evlist->cpus, evlist->threads, 748 group, group_fd); 749 if (err < 0) 750 goto out_err; 751 } 752 753 return 0; 754 out_err: 755 ncpus = evlist->cpus ? evlist->cpus->nr : 1; 756 nthreads = evlist->threads ? evlist->threads->nr : 1; 757 758 list_for_each_entry_reverse(evsel, &evlist->entries, node) 759 perf_evsel__close(evsel, ncpus, nthreads); 760 761 return err; 762 } 763 764 int perf_evlist__prepare_workload(struct perf_evlist *evlist, 765 struct perf_record_opts *opts, 766 const char *argv[]) 767 { 768 int child_ready_pipe[2], go_pipe[2]; 769 char bf; 770 771 if (pipe(child_ready_pipe) < 0) { 772 perror("failed to create 'ready' pipe"); 773 return -1; 774 } 775 776 if (pipe(go_pipe) < 0) { 777 perror("failed to create 'go' pipe"); 778 goto out_close_ready_pipe; 779 } 780 781 evlist->workload.pid = fork(); 782 if (evlist->workload.pid < 0) { 783 perror("failed to fork"); 784 goto out_close_pipes; 785 } 786 787 if (!evlist->workload.pid) { 788 if (opts->pipe_output) 789 dup2(2, 1); 790 791 close(child_ready_pipe[0]); 792 close(go_pipe[1]); 793 fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC); 794 795 /* 796 * Do a dummy execvp to get the PLT entry resolved, 797 * so we avoid the resolver overhead on the real 798 * execvp call. 799 */ 800 execvp("", (char **)argv); 801 802 /* 803 * Tell the parent we're ready to go 804 */ 805 close(child_ready_pipe[1]); 806 807 /* 808 * Wait until the parent tells us to go. 809 */ 810 if (read(go_pipe[0], &bf, 1) == -1) 811 perror("unable to read pipe"); 812 813 execvp(argv[0], (char **)argv); 814 815 perror(argv[0]); 816 kill(getppid(), SIGUSR1); 817 exit(-1); 818 } 819 820 if (!opts->system_wide && opts->target_tid == -1 && opts->target_pid == -1) 821 evlist->threads->map[0] = evlist->workload.pid; 822 823 close(child_ready_pipe[1]); 824 close(go_pipe[0]); 825 /* 826 * wait for child to settle 827 */ 828 if (read(child_ready_pipe[0], &bf, 1) == -1) { 829 perror("unable to read pipe"); 830 goto out_close_pipes; 831 } 832 833 evlist->workload.cork_fd = go_pipe[1]; 834 close(child_ready_pipe[0]); 835 return 0; 836 837 out_close_pipes: 838 close(go_pipe[0]); 839 close(go_pipe[1]); 840 out_close_ready_pipe: 841 close(child_ready_pipe[0]); 842 close(child_ready_pipe[1]); 843 return -1; 844 } 845 846 int perf_evlist__start_workload(struct perf_evlist *evlist) 847 { 848 if (evlist->workload.cork_fd > 0) { 849 /* 850 * Remove the cork, let it rip! 851 */ 852 return close(evlist->workload.cork_fd); 853 } 854 855 return 0; 856 } 857