tools/perf/util/evlist.c

   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 "target.h"
  15 #include "evlist.h"
  16 #include "evsel.h"
  17 #include <unistd.h>
  18
  19 #include "parse-events.h"
  20
  21 #include <sys/mman.h>
  22
  23 #include <linux/bitops.h>
  24 #include <linux/hash.h>
  25
  26 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
  27 #define SID(e, x, y) xyarray__entry(e->sample_id, x, y)
  28
  29 void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus,
  30                        struct thread_map *threads)
  31 {
  32         int i;
  33
  34         for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
  35                 INIT_HLIST_HEAD(&evlist->heads[i]);
  36         INIT_LIST_HEAD(&evlist->entries);
  37         perf_evlist__set_maps(evlist, cpus, threads);
  38         evlist->workload.pid = -1;
  39 }
  40
  41 struct perf_evlist *perf_evlist__new(struct cpu_map *cpus,
  42                                      struct thread_map *threads)
  43 {
  44         struct perf_evlist *evlist = zalloc(sizeof(*evlist));
  45
  46         if (evlist != NULL)
  47                 perf_evlist__init(evlist, cpus, threads);
  48
  49         return evlist;
  50 }
  51
  52 void perf_evlist__config_attrs(struct perf_evlist *evlist,
  53                                struct perf_record_opts *opts)
  54 {
  55         struct perf_evsel *evsel, *first;
  56
  57         if (evlist->cpus->map[0] < 0)
  58                 opts->no_inherit = true;
  59
  60         first = list_entry(evlist->entries.next, struct perf_evsel, node);
  61
  62         list_for_each_entry(evsel, &evlist->entries, node) {
  63                 perf_evsel__config(evsel, opts, first);
  64
  65                 if (evlist->nr_entries > 1)
  66                         evsel->attr.sample_type |= PERF_SAMPLE_ID;
  67         }
  68 }
  69
  70 static void perf_evlist__purge(struct perf_evlist *evlist)
  71 {
  72         struct perf_evsel *pos, *n;
  73
  74         list_for_each_entry_safe(pos, n, &evlist->entries, node) {
  75                 list_del_init(&pos->node);
  76                 perf_evsel__delete(pos);
  77         }
  78
  79         evlist->nr_entries = 0;
  80 }
  81
  82 void perf_evlist__exit(struct perf_evlist *evlist)
  83 {
  84         free(evlist->mmap);
  85         free(evlist->pollfd);
  86         evlist->mmap = NULL;
  87         evlist->pollfd = NULL;
  88 }
  89
  90 void perf_evlist__delete(struct perf_evlist *evlist)
  91 {
  92         perf_evlist__purge(evlist);
  93         perf_evlist__exit(evlist);
  94         free(evlist);
  95 }
  96
  97 void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry)
  98 {
  99         list_add_tail(&entry->node, &evlist->entries);
 100         ++evlist->nr_entries;
 101 }
 102
 103 void perf_evlist__splice_list_tail(struct perf_evlist *evlist,
 104                                    struct list_head *list,
 105                                    int nr_entries)
 106 {
 107         list_splice_tail(list, &evlist->entries);
 108         evlist->nr_entries += nr_entries;
 109 }
 110
 111 int perf_evlist__add_default(struct perf_evlist *evlist)
 112 {
 113         struct perf_event_attr attr = {
 114                 .type = PERF_TYPE_HARDWARE,
 115                 .config = PERF_COUNT_HW_CPU_CYCLES,
 116         };
 117         struct perf_evsel *evsel;
 118
 119         event_attr_init(&attr);
 120
 121         evsel = perf_evsel__new(&attr, 0);
 122         if (evsel == NULL)
 123                 goto error;
 124
 125         /* use strdup() because free(evsel) assumes name is allocated */
 126         evsel->name = strdup("cycles");
 127         if (!evsel->name)
 128                 goto error_free;
 129
 130         perf_evlist__add(evlist, evsel);
 131         return 0;
 132 error_free:
 133         perf_evsel__delete(evsel);
 134 error:
 135         return -ENOMEM;
 136 }
 137
 138 int perf_evlist__add_attrs(struct perf_evlist *evlist,
 139                            struct perf_event_attr *attrs, size_t nr_attrs)
 140 {
 141         struct perf_evsel *evsel, *n;
 142         LIST_HEAD(head);
 143         size_t i;
 144
 145         for (i = 0; i < nr_attrs; i++) {
 146                 evsel = perf_evsel__new(attrs + i, evlist->nr_entries + i);
 147                 if (evsel == NULL)
 148                         goto out_delete_partial_list;
 149                 list_add_tail(&evsel->node, &head);
 150         }
 151
 152         perf_evlist__splice_list_tail(evlist, &head, nr_attrs);
 153
 154         return 0;
 155
 156 out_delete_partial_list:
 157         list_for_each_entry_safe(evsel, n, &head, node)
 158                 perf_evsel__delete(evsel);
 159         return -1;
 160 }
 161
 162 int __perf_evlist__add_default_attrs(struct perf_evlist *evlist,
 163                                      struct perf_event_attr *attrs, size_t nr_attrs)
 164 {
 165         size_t i;
 166
 167         for (i = 0; i < nr_attrs; i++)
 168                 event_attr_init(attrs + i);
 169
 170         return perf_evlist__add_attrs(evlist, attrs, nr_attrs);
 171 }
 172
 173 static int trace_event__id(const char *evname)
 174 {
 175         char *filename, *colon;
 176         int err = -1, fd;
 177
 178         if (asprintf(&filename, "%s/%s/id", tracing_events_path, evname) < 0)
 179                 return -1;
 180
 181         colon = strrchr(filename, ':');
 182         if (colon != NULL)
 183                 *colon = '/';
 184
 185         fd = open(filename, O_RDONLY);
 186         if (fd >= 0) {
 187                 char id[16];
 188                 if (read(fd, id, sizeof(id)) > 0)
 189                         err = atoi(id);
 190                 close(fd);
 191         }
 192
 193         free(filename);
 194         return err;
 195 }
 196
 197 int perf_evlist__add_tracepoints(struct perf_evlist *evlist,
 198                                  const char *tracepoints[],
 199                                  size_t nr_tracepoints)
 200 {
 201         int err;
 202         size_t i;
 203         struct perf_event_attr *attrs = zalloc(nr_tracepoints * sizeof(*attrs));
 204
 205         if (attrs == NULL)
 206                 return -1;
 207
 208         for (i = 0; i < nr_tracepoints; i++) {
 209                 err = trace_event__id(tracepoints[i]);
 210
 211                 if (err < 0)
 212                         goto out_free_attrs;
 213
 214                 attrs[i].type          = PERF_TYPE_TRACEPOINT;
 215                 attrs[i].config        = err;
 216                 attrs[i].sample_type   = (PERF_SAMPLE_RAW | PERF_SAMPLE_TIME |
 217                                           PERF_SAMPLE_CPU);
 218                 attrs[i].sample_period = 1;
 219         }
 220
 221         err = perf_evlist__add_attrs(evlist, attrs, nr_tracepoints);
 222 out_free_attrs:
 223         free(attrs);
 224         return err;
 225 }
 226
 227 struct perf_evsel *
 228 perf_evlist__find_tracepoint_by_id(struct perf_evlist *evlist, int id)
 229 {
 230         struct perf_evsel *evsel;
 231
 232         list_for_each_entry(evsel, &evlist->entries, node) {
 233                 if (evsel->attr.type   == PERF_TYPE_TRACEPOINT &&
 234                     (int)evsel->attr.config == id)
 235                         return evsel;
 236         }
 237
 238         return NULL;
 239 }
 240
 241 int perf_evlist__set_tracepoints_handlers(struct perf_evlist *evlist,
 242                                           const struct perf_evsel_str_handler *assocs,
 243                                           size_t nr_assocs)
 244 {
 245         struct perf_evsel *evsel;
 246         int err;
 247         size_t i;
 248
 249         for (i = 0; i < nr_assocs; i++) {
 250                 err = trace_event__id(assocs[i].name);
 251                 if (err < 0)
 252                         goto out;
 253
 254                 evsel = perf_evlist__find_tracepoint_by_id(evlist, err);
 255                 if (evsel == NULL)
 256                         continue;
 257
 258                 err = -EEXIST;
 259                 if (evsel->handler.func != NULL)
 260                         goto out;
 261                 evsel->handler.func = assocs[i].handler;
 262         }
 263
 264         err = 0;
 265 out:
 266         return err;
 267 }
 268
 269 void perf_evlist__disable(struct perf_evlist *evlist)
 270 {
 271         int cpu, thread;
 272         struct perf_evsel *pos;
 273
 274         for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
 275                 list_for_each_entry(pos, &evlist->entries, node) {
 276                         for (thread = 0; thread < evlist->threads->nr; thread++)
 277                                 ioctl(FD(pos, cpu, thread),
 278                                       PERF_EVENT_IOC_DISABLE, 0);
 279                 }
 280         }
 281 }
 282
 283 void perf_evlist__enable(struct perf_evlist *evlist)
 284 {
 285         int cpu, thread;
 286         struct perf_evsel *pos;
 287
 288         for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
 289                 list_for_each_entry(pos, &evlist->entries, node) {
 290                         for (thread = 0; thread < evlist->threads->nr; thread++)
 291                                 ioctl(FD(pos, cpu, thread),
 292                                       PERF_EVENT_IOC_ENABLE, 0);
 293                 }
 294         }
 295 }
 296
 297 static int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
 298 {
 299         int nfds = evlist->cpus->nr * evlist->threads->nr * evlist->nr_entries;
 300         evlist->pollfd = malloc(sizeof(struct pollfd) * nfds);
 301         return evlist->pollfd != NULL ? 0 : -ENOMEM;
 302 }
 303
 304 void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd)
 305 {
 306         fcntl(fd, F_SETFL, O_NONBLOCK);
 307         evlist->pollfd[evlist->nr_fds].fd = fd;
 308         evlist->pollfd[evlist->nr_fds].events = POLLIN;
 309         evlist->nr_fds++;
 310 }
 311
 312 static void perf_evlist__id_hash(struct perf_evlist *evlist,
 313                                  struct perf_evsel *evsel,
 314                                  int cpu, int thread, u64 id)
 315 {
 316         int hash;
 317         struct perf_sample_id *sid = SID(evsel, cpu, thread);
 318
 319         sid->id = id;
 320         sid->evsel = evsel;
 321         hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS);
 322         hlist_add_head(&sid->node, &evlist->heads[hash]);
 323 }
 324
 325 void perf_evlist__id_add(struct perf_evlist *evlist, struct perf_evsel *evsel,
 326                          int cpu, int thread, u64 id)
 327 {
 328         perf_evlist__id_hash(evlist, evsel, cpu, thread, id);
 329         evsel->id[evsel->ids++] = id;
 330 }
 331
 332 static int perf_evlist__id_add_fd(struct perf_evlist *evlist,
 333                                   struct perf_evsel *evsel,
 334                                   int cpu, int thread, int fd)
 335 {
 336         u64 read_data[4] = { 0, };
 337         int id_idx = 1; /* The first entry is the counter value */
 338
 339         if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
 340             read(fd, &read_data, sizeof(read_data)) == -1)
 341                 return -1;
 342
 343         if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
 344                 ++id_idx;
 345         if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
 346                 ++id_idx;
 347
 348         perf_evlist__id_add(evlist, evsel, cpu, thread, read_data[id_idx]);
 349         return 0;
 350 }
 351
 352 struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id)
 353 {
 354         struct hlist_head *head;
 355         struct hlist_node *pos;
 356         struct perf_sample_id *sid;
 357         int hash;
 358
 359         if (evlist->nr_entries == 1)
 360                 return list_entry(evlist->entries.next, struct perf_evsel, node);
 361
 362         hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
 363         head = &evlist->heads[hash];
 364
 365         hlist_for_each_entry(sid, pos, head, node)
 366                 if (sid->id == id)
 367                         return sid->evsel;
 368
 369         if (!perf_evlist__sample_id_all(evlist))
 370                 return list_entry(evlist->entries.next, struct perf_evsel, node);
 371
 372         return NULL;
 373 }
 374
 375 union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx)
 376 {
 377         /* XXX Move this to perf.c, making it generally available */
 378         unsigned int page_size = sysconf(_SC_PAGE_SIZE);
 379         struct perf_mmap *md = &evlist->mmap[idx];
 380         unsigned int head = perf_mmap__read_head(md);
 381         unsigned int old = md->prev;
 382         unsigned char *data = md->base + page_size;
 383         union perf_event *event = NULL;
 384
 385         if (evlist->overwrite) {
 386                 /*
 387                  * If we're further behind than half the buffer, there's a chance
 388                  * the writer will bite our tail and mess up the samples under us.
 389                  *
 390                  * If we somehow ended up ahead of the head, we got messed up.
 391                  *
 392                  * In either case, truncate and restart at head.
 393                  */
 394                 int diff = head - old;
 395                 if (diff > md->mask / 2 || diff < 0) {
 396                         fprintf(stderr, "WARNING: failed to keep up with mmap data.\n");
 397
 398                         /*
 399                          * head points to a known good entry, start there.
 400                          */
 401                         old = head;
 402                 }
 403         }
 404
 405         if (old != head) {
 406                 size_t size;
 407
 408                 event = (union perf_event *)&data[old & md->mask];
 409                 size = event->header.size;
 410
 411                 /*
 412                  * Event straddles the mmap boundary -- header should always
 413                  * be inside due to u64 alignment of output.
 414                  */
 415                 if ((old & md->mask) + size != ((old + size) & md->mask)) {
 416                         unsigned int offset = old;
 417                         unsigned int len = min(sizeof(*event), size), cpy;
 418                         void *dst = &evlist->event_copy;
 419
 420                         do {
 421                                 cpy = min(md->mask + 1 - (offset & md->mask), len);
 422                                 memcpy(dst, &data[offset & md->mask], cpy);
 423                                 offset += cpy;
 424                                 dst += cpy;
 425                                 len -= cpy;
 426                         } while (len);
 427
 428                         event = &evlist->event_copy;
 429                 }
 430
 431                 old += size;
 432         }
 433
 434         md->prev = old;
 435
 436         if (!evlist->overwrite)
 437                 perf_mmap__write_tail(md, old);
 438
 439         return event;
 440 }
 441
 442 void perf_evlist__munmap(struct perf_evlist *evlist)
 443 {
 444         int i;
 445
 446         for (i = 0; i < evlist->nr_mmaps; i++) {
 447                 if (evlist->mmap[i].base != NULL) {
 448                         munmap(evlist->mmap[i].base, evlist->mmap_len);
 449                         evlist->mmap[i].base = NULL;
 450                 }
 451         }
 452
 453         free(evlist->mmap);
 454         evlist->mmap = NULL;
 455 }
 456
 457 static int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
 458 {
 459         evlist->nr_mmaps = evlist->cpus->nr;
 460         if (evlist->cpus->map[0] == -1)
 461                 evlist->nr_mmaps = evlist->threads->nr;
 462         evlist->mmap = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap));
 463         return evlist->mmap != NULL ? 0 : -ENOMEM;
 464 }
 465
 466 static int __perf_evlist__mmap(struct perf_evlist *evlist,
 467                                int idx, int prot, int mask, int fd)
 468 {
 469         evlist->mmap[idx].prev = 0;
 470         evlist->mmap[idx].mask = mask;
 471         evlist->mmap[idx].base = mmap(NULL, evlist->mmap_len, prot,
 472                                       MAP_SHARED, fd, 0);
 473         if (evlist->mmap[idx].base == MAP_FAILED) {
 474                 evlist->mmap[idx].base = NULL;
 475                 return -1;
 476         }
 477
 478         perf_evlist__add_pollfd(evlist, fd);
 479         return 0;
 480 }
 481
 482 static int perf_evlist__mmap_per_cpu(struct perf_evlist *evlist, int prot, int mask)
 483 {
 484         struct perf_evsel *evsel;
 485         int cpu, thread;
 486
 487         for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
 488                 int output = -1;
 489
 490                 for (thread = 0; thread < evlist->threads->nr; thread++) {
 491                         list_for_each_entry(evsel, &evlist->entries, node) {
 492                                 int fd = FD(evsel, cpu, thread);
 493
 494                                 if (output == -1) {
 495                                         output = fd;
 496                                         if (__perf_evlist__mmap(evlist, cpu,
 497                                                                 prot, mask, output) < 0)
 498                                                 goto out_unmap;
 499                                 } else {
 500                                         if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, output) != 0)
 501                                                 goto out_unmap;
 502                                 }
 503
 504                                 if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
 505                                     perf_evlist__id_add_fd(evlist, evsel, cpu, thread, fd) < 0)
 506                                         goto out_unmap;
 507                         }
 508                 }
 509         }
 510
 511         return 0;
 512
 513 out_unmap:
 514         for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
 515                 if (evlist->mmap[cpu].base != NULL) {
 516                         munmap(evlist->mmap[cpu].base, evlist->mmap_len);
 517                         evlist->mmap[cpu].base = NULL;
 518                 }
 519         }
 520         return -1;
 521 }
 522
 523 static int perf_evlist__mmap_per_thread(struct perf_evlist *evlist, int prot, int mask)
 524 {
 525         struct perf_evsel *evsel;
 526         int thread;
 527
 528         for (thread = 0; thread < evlist->threads->nr; thread++) {
 529                 int output = -1;
 530
 531                 list_for_each_entry(evsel, &evlist->entries, node) {
 532                         int fd = FD(evsel, 0, thread);
 533
 534                         if (output == -1) {
 535                                 output = fd;
 536                                 if (__perf_evlist__mmap(evlist, thread,
 537                                                         prot, mask, output) < 0)
 538                                         goto out_unmap;
 539                         } else {
 540                                 if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, output) != 0)
 541                                         goto out_unmap;
 542                         }
 543
 544                         if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
 545                             perf_evlist__id_add_fd(evlist, evsel, 0, thread, fd) < 0)
 546                                 goto out_unmap;
 547                 }
 548         }
 549
 550         return 0;
 551
 552 out_unmap:
 553         for (thread = 0; thread < evlist->threads->nr; thread++) {
 554                 if (evlist->mmap[thread].base != NULL) {
 555                         munmap(evlist->mmap[thread].base, evlist->mmap_len);
 556                         evlist->mmap[thread].base = NULL;
 557                 }
 558         }
 559         return -1;
 560 }
 561
 562 /** perf_evlist__mmap - Create per cpu maps to receive events
 563  *
 564  * @evlist - list of events
 565  * @pages - map length in pages
 566  * @overwrite - overwrite older events?
 567  *
 568  * If overwrite is false the user needs to signal event consuption using:
 569  *
 570  *      struct perf_mmap *m = &evlist->mmap[cpu];
 571  *      unsigned int head = perf_mmap__read_head(m);
 572  *
 573  *      perf_mmap__write_tail(m, head)
 574  *
 575  * Using perf_evlist__read_on_cpu does this automatically.
 576  */
 577 int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
 578                       bool overwrite)
 579 {
 580         unsigned int page_size = sysconf(_SC_PAGE_SIZE);
 581         struct perf_evsel *evsel;
 582         const struct cpu_map *cpus = evlist->cpus;
 583         const struct thread_map *threads = evlist->threads;
 584         int prot = PROT_READ | (overwrite ? 0 : PROT_WRITE), mask;
 585
 586         /* 512 kiB: default amount of unprivileged mlocked memory */
 587         if (pages == UINT_MAX)
 588                 pages = (512 * 1024) / page_size;
 589         else if (!is_power_of_2(pages))
 590                 return -EINVAL;
 591
 592         mask = pages * page_size - 1;
 593
 594         if (evlist->mmap == NULL && perf_evlist__alloc_mmap(evlist) < 0)
 595                 return -ENOMEM;
 596
 597         if (evlist->pollfd == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
 598                 return -ENOMEM;
 599
 600         evlist->overwrite = overwrite;
 601         evlist->mmap_len = (pages + 1) * page_size;
 602
 603         list_for_each_entry(evsel, &evlist->entries, node) {
 604                 if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
 605                     evsel->sample_id == NULL &&
 606                     perf_evsel__alloc_id(evsel, cpus->nr, threads->nr) < 0)
 607                         return -ENOMEM;
 608         }
 609
 610         if (evlist->cpus->map[0] == -1)
 611                 return perf_evlist__mmap_per_thread(evlist, prot, mask);
 612
 613         return perf_evlist__mmap_per_cpu(evlist, prot, mask);
 614 }
 615
 616 int perf_evlist__create_maps(struct perf_evlist *evlist,
 617                              struct perf_target *target)
 618 {
 619         evlist->threads = thread_map__new_str(target->pid, target->tid,
 620                                               target->uid);
 621
 622         if (evlist->threads == NULL)
 623                 return -1;
 624
 625         if (perf_target__has_task(target))
 626                 evlist->cpus = cpu_map__dummy_new();
 627         else if (!perf_target__has_cpu(target) && !target->uses_mmap)
 628                 evlist->cpus = cpu_map__dummy_new();
 629         else
 630                 evlist->cpus = cpu_map__new(target->cpu_list);
 631
 632         if (evlist->cpus == NULL)
 633                 goto out_delete_threads;
 634
 635         return 0;
 636
 637 out_delete_threads:
 638         thread_map__delete(evlist->threads);
 639         return -1;
 640 }
 641
 642 void perf_evlist__delete_maps(struct perf_evlist *evlist)
 643 {
 644         cpu_map__delete(evlist->cpus);
 645         thread_map__delete(evlist->threads);
 646         evlist->cpus    = NULL;
 647         evlist->threads = NULL;
 648 }
 649
 650 int perf_evlist__set_filters(struct perf_evlist *evlist)
 651 {
 652         const struct thread_map *threads = evlist->threads;
 653         const struct cpu_map *cpus = evlist->cpus;
 654         struct perf_evsel *evsel;
 655         char *filter;
 656         int thread;
 657         int cpu;
 658         int err;
 659         int fd;
 660
 661         list_for_each_entry(evsel, &evlist->entries, node) {
 662                 filter = evsel->filter;
 663                 if (!filter)
 664                         continue;
 665                 for (cpu = 0; cpu < cpus->nr; cpu++) {
 666                         for (thread = 0; thread < threads->nr; thread++) {
 667                                 fd = FD(evsel, cpu, thread);
 668                                 err = ioctl(fd, PERF_EVENT_IOC_SET_FILTER, filter);
 669                                 if (err)
 670                                         return err;
 671                         }
 672                 }
 673         }
 674
 675         return 0;
 676 }
 677
 678 bool perf_evlist__valid_sample_type(const struct perf_evlist *evlist)
 679 {
 680         struct perf_evsel *pos, *first;
 681
 682         pos = first = list_entry(evlist->entries.next, struct perf_evsel, node);
 683
 684         list_for_each_entry_continue(pos, &evlist->entries, node) {
 685                 if (first->attr.sample_type != pos->attr.sample_type)
 686                         return false;
 687         }
 688
 689         return true;
 690 }
 691
 692 u64 perf_evlist__sample_type(const struct perf_evlist *evlist)
 693 {
 694         struct perf_evsel *first;
 695
 696         first = list_entry(evlist->entries.next, struct perf_evsel, node);
 697         return first->attr.sample_type;
 698 }
 699
 700 u16 perf_evlist__id_hdr_size(const struct perf_evlist *evlist)
 701 {
 702         struct perf_evsel *first;
 703         struct perf_sample *data;
 704         u64 sample_type;
 705         u16 size = 0;
 706
 707         first = list_entry(evlist->entries.next, struct perf_evsel, node);
 708
 709         if (!first->attr.sample_id_all)
 710                 goto out;
 711
 712         sample_type = first->attr.sample_type;
 713
 714         if (sample_type & PERF_SAMPLE_TID)
 715                 size += sizeof(data->tid) * 2;
 716
 717        if (sample_type & PERF_SAMPLE_TIME)
 718                 size += sizeof(data->time);
 719
 720         if (sample_type & PERF_SAMPLE_ID)
 721                 size += sizeof(data->id);
 722
 723         if (sample_type & PERF_SAMPLE_STREAM_ID)
 724                 size += sizeof(data->stream_id);
 725
 726         if (sample_type & PERF_SAMPLE_CPU)
 727                 size += sizeof(data->cpu) * 2;
 728 out:
 729         return size;
 730 }
 731
 732 bool perf_evlist__valid_sample_id_all(const struct perf_evlist *evlist)
 733 {
 734         struct perf_evsel *pos, *first;
 735
 736         pos = first = list_entry(evlist->entries.next, struct perf_evsel, node);
 737
 738         list_for_each_entry_continue(pos, &evlist->entries, node) {
 739                 if (first->attr.sample_id_all != pos->attr.sample_id_all)
 740                         return false;
 741         }
 742
 743         return true;
 744 }
 745
 746 bool perf_evlist__sample_id_all(const struct perf_evlist *evlist)
 747 {
 748         struct perf_evsel *first;
 749
 750         first = list_entry(evlist->entries.next, struct perf_evsel, node);
 751         return first->attr.sample_id_all;
 752 }
 753
 754 void perf_evlist__set_selected(struct perf_evlist *evlist,
 755                                struct perf_evsel *evsel)
 756 {
 757         evlist->selected = evsel;
 758 }
 759
 760 int perf_evlist__open(struct perf_evlist *evlist, bool group)
 761 {
 762         struct perf_evsel *evsel, *first;
 763         int err, ncpus, nthreads;
 764
 765         first = list_entry(evlist->entries.next, struct perf_evsel, node);
 766
 767         list_for_each_entry(evsel, &evlist->entries, node) {
 768                 struct xyarray *group_fd = NULL;
 769
 770                 if (group && evsel != first)
 771                         group_fd = first->fd;
 772
 773                 err = perf_evsel__open(evsel, evlist->cpus, evlist->threads,
 774                                        group, group_fd);
 775                 if (err < 0)
 776                         goto out_err;
 777         }
 778
 779         return 0;
 780 out_err:
 781         ncpus = evlist->cpus ? evlist->cpus->nr : 1;
 782         nthreads = evlist->threads ? evlist->threads->nr : 1;
 783
 784         list_for_each_entry_reverse(evsel, &evlist->entries, node)
 785                 perf_evsel__close(evsel, ncpus, nthreads);
 786
 787         errno = -err;
 788         return err;
 789 }
 790
 791 int perf_evlist__prepare_workload(struct perf_evlist *evlist,
 792                                   struct perf_record_opts *opts,
 793                                   const char *argv[])
 794 {
 795         int child_ready_pipe[2], go_pipe[2];
 796         char bf;
 797
 798         if (pipe(child_ready_pipe) < 0) {
 799                 perror("failed to create 'ready' pipe");
 800                 return -1;
 801         }
 802
 803         if (pipe(go_pipe) < 0) {
 804                 perror("failed to create 'go' pipe");
 805                 goto out_close_ready_pipe;
 806         }
 807
 808         evlist->workload.pid = fork();
 809         if (evlist->workload.pid < 0) {
 810                 perror("failed to fork");
 811                 goto out_close_pipes;
 812         }
 813
 814         if (!evlist->workload.pid) {
 815                 if (opts->pipe_output)
 816                         dup2(2, 1);
 817
 818                 close(child_ready_pipe[0]);
 819                 close(go_pipe[1]);
 820                 fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
 821
 822                 /*
 823                  * Do a dummy execvp to get the PLT entry resolved,
 824                  * so we avoid the resolver overhead on the real
 825                  * execvp call.
 826                  */
 827                 execvp("", (char **)argv);
 828
 829                 /*
 830                  * Tell the parent we're ready to go
 831                  */
 832                 close(child_ready_pipe[1]);
 833
 834                 /*
 835                  * Wait until the parent tells us to go.
 836                  */
 837                 if (read(go_pipe[0], &bf, 1) == -1)
 838                         perror("unable to read pipe");
 839
 840                 execvp(argv[0], (char **)argv);
 841
 842                 perror(argv[0]);
 843                 kill(getppid(), SIGUSR1);
 844                 exit(-1);
 845         }
 846
 847         if (perf_target__none(&opts->target))
 848                 evlist->threads->map[0] = evlist->workload.pid;
 849
 850         close(child_ready_pipe[1]);
 851         close(go_pipe[0]);
 852         /*
 853          * wait for child to settle
 854          */
 855         if (read(child_ready_pipe[0], &bf, 1) == -1) {
 856                 perror("unable to read pipe");
 857                 goto out_close_pipes;
 858         }
 859
 860         evlist->workload.cork_fd = go_pipe[1];
 861         close(child_ready_pipe[0]);
 862         return 0;
 863
 864 out_close_pipes:
 865         close(go_pipe[0]);
 866         close(go_pipe[1]);
 867 out_close_ready_pipe:
 868         close(child_ready_pipe[0]);
 869         close(child_ready_pipe[1]);
 870         return -1;
 871 }
 872
 873 int perf_evlist__start_workload(struct perf_evlist *evlist)
 874 {
 875         if (evlist->workload.cork_fd > 0) {
 876                 /*
 877                  * Remove the cork, let it rip!
 878                  */
 879                 return close(evlist->workload.cork_fd);
 880         }
 881
 882         return 0;
 883 }