tools/perf/util/evlist.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2011, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
   4  *
   5  * Parts came from builtin-{top,stat,record}.c, see those files for further
   6  * copyright notes.
   7  */
   8 #include <api/fs/fs.h>
   9 #include <errno.h>
  10 #include <inttypes.h>
  11 #include <poll.h>
  12 #include "cpumap.h"
  13 #include "util/mmap.h"
  14 #include "thread_map.h"
  15 #include "target.h"
  16 #include "evlist.h"
  17 #include "evsel.h"
  18 #include "debug.h"
  19 #include "units.h"
  20 #include "bpf_counter.h"
  21 #include <internal/lib.h> // page_size
  22 #include "affinity.h"
  23 #include "../perf.h"
  24 #include "asm/bug.h"
  25 #include "bpf-event.h"
  26 #include "util/string2.h"
  27 #include "util/perf_api_probe.h"
  28 #include "util/evsel_fprintf.h"
  29 #include "util/evlist-hybrid.h"
  30 #include <signal.h>
  31 #include <unistd.h>
  32 #include <sched.h>
  33 #include <stdlib.h>
  34
  35 #include "parse-events.h"
  36 #include <subcmd/parse-options.h>
  37
  38 #include <fcntl.h>
  39 #include <sys/ioctl.h>
  40 #include <sys/mman.h>
  41 #include <sys/prctl.h>
  42
  43 #include <linux/bitops.h>
  44 #include <linux/hash.h>
  45 #include <linux/log2.h>
  46 #include <linux/err.h>
  47 #include <linux/string.h>
  48 #include <linux/zalloc.h>
  49 #include <perf/evlist.h>
  50 #include <perf/evsel.h>
  51 #include <perf/cpumap.h>
  52 #include <perf/mmap.h>
  53
  54 #include <internal/xyarray.h>
  55
  56 #ifdef LACKS_SIGQUEUE_PROTOTYPE
  57 int sigqueue(pid_t pid, int sig, const union sigval value);
  58 #endif
  59
  60 #define FD(e, x, y) (*(int *)xyarray__entry(e->core.fd, x, y))
  61 #define SID(e, x, y) xyarray__entry(e->core.sample_id, x, y)
  62
  63 void evlist__init(struct evlist *evlist, struct perf_cpu_map *cpus,
  64                   struct perf_thread_map *threads)
  65 {
  66         perf_evlist__init(&evlist->core);
  67         perf_evlist__set_maps(&evlist->core, cpus, threads);
  68         evlist->workload.pid = -1;
  69         evlist->bkw_mmap_state = BKW_MMAP_NOTREADY;
  70         evlist->ctl_fd.fd = -1;
  71         evlist->ctl_fd.ack = -1;
  72         evlist->ctl_fd.pos = -1;
  73 }
  74
  75 struct evlist *evlist__new(void)
  76 {
  77         struct evlist *evlist = zalloc(sizeof(*evlist));
  78
  79         if (evlist != NULL)
  80                 evlist__init(evlist, NULL, NULL);
  81
  82         return evlist;
  83 }
  84
  85 struct evlist *evlist__new_default(void)
  86 {
  87         struct evlist *evlist = evlist__new();
  88
  89         if (evlist && evlist__add_default(evlist)) {
  90                 evlist__delete(evlist);
  91                 evlist = NULL;
  92         }
  93
  94         return evlist;
  95 }
  96
  97 struct evlist *evlist__new_dummy(void)
  98 {
  99         struct evlist *evlist = evlist__new();
 100
 101         if (evlist && evlist__add_dummy(evlist)) {
 102                 evlist__delete(evlist);
 103                 evlist = NULL;
 104         }
 105
 106         return evlist;
 107 }
 108
 109 /**
 110  * evlist__set_id_pos - set the positions of event ids.
 111  * @evlist: selected event list
 112  *
 113  * Events with compatible sample types all have the same id_pos
 114  * and is_pos.  For convenience, put a copy on evlist.
 115  */
 116 void evlist__set_id_pos(struct evlist *evlist)
 117 {
 118         struct evsel *first = evlist__first(evlist);
 119
 120         evlist->id_pos = first->id_pos;
 121         evlist->is_pos = first->is_pos;
 122 }
 123
 124 static void evlist__update_id_pos(struct evlist *evlist)
 125 {
 126         struct evsel *evsel;
 127
 128         evlist__for_each_entry(evlist, evsel)
 129                 evsel__calc_id_pos(evsel);
 130
 131         evlist__set_id_pos(evlist);
 132 }
 133
 134 static void evlist__purge(struct evlist *evlist)
 135 {
 136         struct evsel *pos, *n;
 137
 138         evlist__for_each_entry_safe(evlist, n, pos) {
 139                 list_del_init(&pos->core.node);
 140                 pos->evlist = NULL;
 141                 evsel__delete(pos);
 142         }
 143
 144         evlist->core.nr_entries = 0;
 145 }
 146
 147 void evlist__exit(struct evlist *evlist)
 148 {
 149         zfree(&evlist->mmap);
 150         zfree(&evlist->overwrite_mmap);
 151         perf_evlist__exit(&evlist->core);
 152 }
 153
 154 void evlist__delete(struct evlist *evlist)
 155 {
 156         if (evlist == NULL)
 157                 return;
 158
 159         evlist__munmap(evlist);
 160         evlist__close(evlist);
 161         evlist__purge(evlist);
 162         evlist__exit(evlist);
 163         free(evlist);
 164 }
 165
 166 void evlist__add(struct evlist *evlist, struct evsel *entry)
 167 {
 168         entry->evlist = evlist;
 169         entry->idx = evlist->core.nr_entries;
 170         entry->tracking = !entry->idx;
 171
 172         perf_evlist__add(&evlist->core, &entry->core);
 173
 174         if (evlist->core.nr_entries == 1)
 175                 evlist__set_id_pos(evlist);
 176 }
 177
 178 void evlist__remove(struct evlist *evlist, struct evsel *evsel)
 179 {
 180         evsel->evlist = NULL;
 181         perf_evlist__remove(&evlist->core, &evsel->core);
 182 }
 183
 184 void evlist__splice_list_tail(struct evlist *evlist, struct list_head *list)
 185 {
 186         while (!list_empty(list)) {
 187                 struct evsel *evsel, *temp, *leader = NULL;
 188
 189                 __evlist__for_each_entry_safe(list, temp, evsel) {
 190                         list_del_init(&evsel->core.node);
 191                         evlist__add(evlist, evsel);
 192                         leader = evsel;
 193                         break;
 194                 }
 195
 196                 __evlist__for_each_entry_safe(list, temp, evsel) {
 197                         if (evsel->leader == leader) {
 198                                 list_del_init(&evsel->core.node);
 199                                 evlist__add(evlist, evsel);
 200                         }
 201                 }
 202         }
 203 }
 204
 205 int __evlist__set_tracepoints_handlers(struct evlist *evlist,
 206                                        const struct evsel_str_handler *assocs, size_t nr_assocs)
 207 {
 208         size_t i;
 209         int err;
 210
 211         for (i = 0; i < nr_assocs; i++) {
 212                 // Adding a handler for an event not in this evlist, just ignore it.
 213                 struct evsel *evsel = evlist__find_tracepoint_by_name(evlist, assocs[i].name);
 214                 if (evsel == NULL)
 215                         continue;
 216
 217                 err = -EEXIST;
 218                 if (evsel->handler != NULL)
 219                         goto out;
 220                 evsel->handler = assocs[i].handler;
 221         }
 222
 223         err = 0;
 224 out:
 225         return err;
 226 }
 227
 228 void __evlist__set_leader(struct list_head *list)
 229 {
 230         struct evsel *evsel, *leader;
 231
 232         leader = list_entry(list->next, struct evsel, core.node);
 233         evsel = list_entry(list->prev, struct evsel, core.node);
 234
 235         leader->core.nr_members = evsel->idx - leader->idx + 1;
 236
 237         __evlist__for_each_entry(list, evsel) {
 238                 evsel->leader = leader;
 239         }
 240 }
 241
 242 void evlist__set_leader(struct evlist *evlist)
 243 {
 244         if (evlist->core.nr_entries) {
 245                 evlist->nr_groups = evlist->core.nr_entries > 1 ? 1 : 0;
 246                 __evlist__set_leader(&evlist->core.entries);
 247         }
 248 }
 249
 250 int __evlist__add_default(struct evlist *evlist, bool precise)
 251 {
 252         struct evsel *evsel;
 253
 254         evsel = evsel__new_cycles(precise, PERF_TYPE_HARDWARE,
 255                                   PERF_COUNT_HW_CPU_CYCLES);
 256         if (evsel == NULL)
 257                 return -ENOMEM;
 258
 259         evlist__add(evlist, evsel);
 260         return 0;
 261 }
 262
 263 int evlist__add_dummy(struct evlist *evlist)
 264 {
 265         struct perf_event_attr attr = {
 266                 .type   = PERF_TYPE_SOFTWARE,
 267                 .config = PERF_COUNT_SW_DUMMY,
 268                 .size   = sizeof(attr), /* to capture ABI version */
 269         };
 270         struct evsel *evsel = evsel__new_idx(&attr, evlist->core.nr_entries);
 271
 272         if (evsel == NULL)
 273                 return -ENOMEM;
 274
 275         evlist__add(evlist, evsel);
 276         return 0;
 277 }
 278
 279 static int evlist__add_attrs(struct evlist *evlist, struct perf_event_attr *attrs, size_t nr_attrs)
 280 {
 281         struct evsel *evsel, *n;
 282         LIST_HEAD(head);
 283         size_t i;
 284
 285         for (i = 0; i < nr_attrs; i++) {
 286                 evsel = evsel__new_idx(attrs + i, evlist->core.nr_entries + i);
 287                 if (evsel == NULL)
 288                         goto out_delete_partial_list;
 289                 list_add_tail(&evsel->core.node, &head);
 290         }
 291
 292         evlist__splice_list_tail(evlist, &head);
 293
 294         return 0;
 295
 296 out_delete_partial_list:
 297         __evlist__for_each_entry_safe(&head, n, evsel)
 298                 evsel__delete(evsel);
 299         return -1;
 300 }
 301
 302 int __evlist__add_default_attrs(struct evlist *evlist, struct perf_event_attr *attrs, size_t nr_attrs)
 303 {
 304         size_t i;
 305
 306         for (i = 0; i < nr_attrs; i++)
 307                 event_attr_init(attrs + i);
 308
 309         return evlist__add_attrs(evlist, attrs, nr_attrs);
 310 }
 311
 312 __weak int arch_evlist__add_default_attrs(struct evlist *evlist __maybe_unused)
 313 {
 314         return 0;
 315 }
 316
 317 struct evsel *evlist__find_tracepoint_by_id(struct evlist *evlist, int id)
 318 {
 319         struct evsel *evsel;
 320
 321         evlist__for_each_entry(evlist, evsel) {
 322                 if (evsel->core.attr.type   == PERF_TYPE_TRACEPOINT &&
 323                     (int)evsel->core.attr.config == id)
 324                         return evsel;
 325         }
 326
 327         return NULL;
 328 }
 329
 330 struct evsel *evlist__find_tracepoint_by_name(struct evlist *evlist, const char *name)
 331 {
 332         struct evsel *evsel;
 333
 334         evlist__for_each_entry(evlist, evsel) {
 335                 if ((evsel->core.attr.type == PERF_TYPE_TRACEPOINT) &&
 336                     (strcmp(evsel->name, name) == 0))
 337                         return evsel;
 338         }
 339
 340         return NULL;
 341 }
 342
 343 int evlist__add_newtp(struct evlist *evlist, const char *sys, const char *name, void *handler)
 344 {
 345         struct evsel *evsel = evsel__newtp(sys, name);
 346
 347         if (IS_ERR(evsel))
 348                 return -1;
 349
 350         evsel->handler = handler;
 351         evlist__add(evlist, evsel);
 352         return 0;
 353 }
 354
 355 static int evlist__nr_threads(struct evlist *evlist, struct evsel *evsel)
 356 {
 357         if (evsel->core.system_wide)
 358                 return 1;
 359         else
 360                 return perf_thread_map__nr(evlist->core.threads);
 361 }
 362
 363 void evlist__cpu_iter_start(struct evlist *evlist)
 364 {
 365         struct evsel *pos;
 366
 367         /*
 368          * Reset the per evsel cpu_iter. This is needed because
 369          * each evsel's cpumap may have a different index space,
 370          * and some operations need the index to modify
 371          * the FD xyarray (e.g. open, close)
 372          */
 373         evlist__for_each_entry(evlist, pos)
 374                 pos->cpu_iter = 0;
 375 }
 376
 377 bool evsel__cpu_iter_skip_no_inc(struct evsel *ev, int cpu)
 378 {
 379         if (ev->cpu_iter >= ev->core.cpus->nr)
 380                 return true;
 381         if (cpu >= 0 && ev->core.cpus->map[ev->cpu_iter] != cpu)
 382                 return true;
 383         return false;
 384 }
 385
 386 bool evsel__cpu_iter_skip(struct evsel *ev, int cpu)
 387 {
 388         if (!evsel__cpu_iter_skip_no_inc(ev, cpu)) {
 389                 ev->cpu_iter++;
 390                 return false;
 391         }
 392         return true;
 393 }
 394
 395 static int evsel__strcmp(struct evsel *pos, char *evsel_name)
 396 {
 397         if (!evsel_name)
 398                 return 0;
 399         if (evsel__is_dummy_event(pos))
 400                 return 1;
 401         return strcmp(pos->name, evsel_name);
 402 }
 403
 404 static int evlist__is_enabled(struct evlist *evlist)
 405 {
 406         struct evsel *pos;
 407
 408         evlist__for_each_entry(evlist, pos) {
 409                 if (!evsel__is_group_leader(pos) || !pos->core.fd)
 410                         continue;
 411                 /* If at least one event is enabled, evlist is enabled. */
 412                 if (!pos->disabled)
 413                         return true;
 414         }
 415         return false;
 416 }
 417
 418 static void __evlist__disable(struct evlist *evlist, char *evsel_name)
 419 {
 420         struct evsel *pos;
 421         struct affinity affinity;
 422         int cpu, i, imm = 0;
 423         bool has_imm = false;
 424
 425         if (affinity__setup(&affinity) < 0)
 426                 return;
 427
 428         /* Disable 'immediate' events last */
 429         for (imm = 0; imm <= 1; imm++) {
 430                 evlist__for_each_cpu(evlist, i, cpu) {
 431                         affinity__set(&affinity, cpu);
 432
 433                         evlist__for_each_entry(evlist, pos) {
 434                                 if (evsel__strcmp(pos, evsel_name))
 435                                         continue;
 436                                 if (evsel__cpu_iter_skip(pos, cpu))
 437                                         continue;
 438                                 if (pos->disabled || !evsel__is_group_leader(pos) || !pos->core.fd)
 439                                         continue;
 440                                 if (pos->immediate)
 441                                         has_imm = true;
 442                                 if (pos->immediate != imm)
 443                                         continue;
 444                                 evsel__disable_cpu(pos, pos->cpu_iter - 1);
 445                         }
 446                 }
 447                 if (!has_imm)
 448                         break;
 449         }
 450
 451         affinity__cleanup(&affinity);
 452         evlist__for_each_entry(evlist, pos) {
 453                 if (evsel__strcmp(pos, evsel_name))
 454                         continue;
 455                 if (!evsel__is_group_leader(pos) || !pos->core.fd)
 456                         continue;
 457                 pos->disabled = true;
 458         }
 459
 460         /*
 461          * If we disabled only single event, we need to check
 462          * the enabled state of the evlist manually.
 463          */
 464         if (evsel_name)
 465                 evlist->enabled = evlist__is_enabled(evlist);
 466         else
 467                 evlist->enabled = false;
 468 }
 469
 470 void evlist__disable(struct evlist *evlist)
 471 {
 472         __evlist__disable(evlist, NULL);
 473 }
 474
 475 void evlist__disable_evsel(struct evlist *evlist, char *evsel_name)
 476 {
 477         __evlist__disable(evlist, evsel_name);
 478 }
 479
 480 static void __evlist__enable(struct evlist *evlist, char *evsel_name)
 481 {
 482         struct evsel *pos;
 483         struct affinity affinity;
 484         int cpu, i;
 485
 486         if (affinity__setup(&affinity) < 0)
 487                 return;
 488
 489         evlist__for_each_cpu(evlist, i, cpu) {
 490                 affinity__set(&affinity, cpu);
 491
 492                 evlist__for_each_entry(evlist, pos) {
 493                         if (evsel__strcmp(pos, evsel_name))
 494                                 continue;
 495                         if (evsel__cpu_iter_skip(pos, cpu))
 496                                 continue;
 497                         if (!evsel__is_group_leader(pos) || !pos->core.fd)
 498                                 continue;
 499                         evsel__enable_cpu(pos, pos->cpu_iter - 1);
 500                 }
 501         }
 502         affinity__cleanup(&affinity);
 503         evlist__for_each_entry(evlist, pos) {
 504                 if (evsel__strcmp(pos, evsel_name))
 505                         continue;
 506                 if (!evsel__is_group_leader(pos) || !pos->core.fd)
 507                         continue;
 508                 pos->disabled = false;
 509         }
 510
 511         /*
 512          * Even single event sets the 'enabled' for evlist,
 513          * so the toggle can work properly and toggle to
 514          * 'disabled' state.
 515          */
 516         evlist->enabled = true;
 517 }
 518
 519 void evlist__enable(struct evlist *evlist)
 520 {
 521         __evlist__enable(evlist, NULL);
 522 }
 523
 524 void evlist__enable_evsel(struct evlist *evlist, char *evsel_name)
 525 {
 526         __evlist__enable(evlist, evsel_name);
 527 }
 528
 529 void evlist__toggle_enable(struct evlist *evlist)
 530 {
 531         (evlist->enabled ? evlist__disable : evlist__enable)(evlist);
 532 }
 533
 534 static int evlist__enable_event_cpu(struct evlist *evlist, struct evsel *evsel, int cpu)
 535 {
 536         int thread;
 537         int nr_threads = evlist__nr_threads(evlist, evsel);
 538
 539         if (!evsel->core.fd)
 540                 return -EINVAL;
 541
 542         for (thread = 0; thread < nr_threads; thread++) {
 543                 int err = ioctl(FD(evsel, cpu, thread), PERF_EVENT_IOC_ENABLE, 0);
 544                 if (err)
 545                         return err;
 546         }
 547         return 0;
 548 }
 549
 550 static int evlist__enable_event_thread(struct evlist *evlist, struct evsel *evsel, int thread)
 551 {
 552         int cpu;
 553         int nr_cpus = perf_cpu_map__nr(evlist->core.cpus);
 554
 555         if (!evsel->core.fd)
 556                 return -EINVAL;
 557
 558         for (cpu = 0; cpu < nr_cpus; cpu++) {
 559                 int err = ioctl(FD(evsel, cpu, thread), PERF_EVENT_IOC_ENABLE, 0);
 560                 if (err)
 561                         return err;
 562         }
 563         return 0;
 564 }
 565
 566 int evlist__enable_event_idx(struct evlist *evlist, struct evsel *evsel, int idx)
 567 {
 568         bool per_cpu_mmaps = !perf_cpu_map__empty(evlist->core.cpus);
 569
 570         if (per_cpu_mmaps)
 571                 return evlist__enable_event_cpu(evlist, evsel, idx);
 572
 573         return evlist__enable_event_thread(evlist, evsel, idx);
 574 }
 575
 576 int evlist__add_pollfd(struct evlist *evlist, int fd)
 577 {
 578         return perf_evlist__add_pollfd(&evlist->core, fd, NULL, POLLIN, fdarray_flag__default);
 579 }
 580
 581 int evlist__filter_pollfd(struct evlist *evlist, short revents_and_mask)
 582 {
 583         return perf_evlist__filter_pollfd(&evlist->core, revents_and_mask);
 584 }
 585
 586 #ifdef HAVE_EVENTFD_SUPPORT
 587 int evlist__add_wakeup_eventfd(struct evlist *evlist, int fd)
 588 {
 589         return perf_evlist__add_pollfd(&evlist->core, fd, NULL, POLLIN,
 590                                        fdarray_flag__nonfilterable);
 591 }
 592 #endif
 593
 594 int evlist__poll(struct evlist *evlist, int timeout)
 595 {
 596         return perf_evlist__poll(&evlist->core, timeout);
 597 }
 598
 599 struct perf_sample_id *evlist__id2sid(struct evlist *evlist, u64 id)
 600 {
 601         struct hlist_head *head;
 602         struct perf_sample_id *sid;
 603         int hash;
 604
 605         hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
 606         head = &evlist->core.heads[hash];
 607
 608         hlist_for_each_entry(sid, head, node)
 609                 if (sid->id == id)
 610                         return sid;
 611
 612         return NULL;
 613 }
 614
 615 struct evsel *evlist__id2evsel(struct evlist *evlist, u64 id)
 616 {
 617         struct perf_sample_id *sid;
 618
 619         if (evlist->core.nr_entries == 1 || !id)
 620                 return evlist__first(evlist);
 621
 622         sid = evlist__id2sid(evlist, id);
 623         if (sid)
 624                 return container_of(sid->evsel, struct evsel, core);
 625
 626         if (!evlist__sample_id_all(evlist))
 627                 return evlist__first(evlist);
 628
 629         return NULL;
 630 }
 631
 632 struct evsel *evlist__id2evsel_strict(struct evlist *evlist, u64 id)
 633 {
 634         struct perf_sample_id *sid;
 635
 636         if (!id)
 637                 return NULL;
 638
 639         sid = evlist__id2sid(evlist, id);
 640         if (sid)
 641                 return container_of(sid->evsel, struct evsel, core);
 642
 643         return NULL;
 644 }
 645
 646 static int evlist__event2id(struct evlist *evlist, union perf_event *event, u64 *id)
 647 {
 648         const __u64 *array = event->sample.array;
 649         ssize_t n;
 650
 651         n = (event->header.size - sizeof(event->header)) >> 3;
 652
 653         if (event->header.type == PERF_RECORD_SAMPLE) {
 654                 if (evlist->id_pos >= n)
 655                         return -1;
 656                 *id = array[evlist->id_pos];
 657         } else {
 658                 if (evlist->is_pos > n)
 659                         return -1;
 660                 n -= evlist->is_pos;
 661                 *id = array[n];
 662         }
 663         return 0;
 664 }
 665
 666 struct evsel *evlist__event2evsel(struct evlist *evlist, union perf_event *event)
 667 {
 668         struct evsel *first = evlist__first(evlist);
 669         struct hlist_head *head;
 670         struct perf_sample_id *sid;
 671         int hash;
 672         u64 id;
 673
 674         if (evlist->core.nr_entries == 1)
 675                 return first;
 676
 677         if (!first->core.attr.sample_id_all &&
 678             event->header.type != PERF_RECORD_SAMPLE)
 679                 return first;
 680
 681         if (evlist__event2id(evlist, event, &id))
 682                 return NULL;
 683
 684         /* Synthesized events have an id of zero */
 685         if (!id)
 686                 return first;
 687
 688         hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
 689         head = &evlist->core.heads[hash];
 690
 691         hlist_for_each_entry(sid, head, node) {
 692                 if (sid->id == id)
 693                         return container_of(sid->evsel, struct evsel, core);
 694         }
 695         return NULL;
 696 }
 697
 698 static int evlist__set_paused(struct evlist *evlist, bool value)
 699 {
 700         int i;
 701
 702         if (!evlist->overwrite_mmap)
 703                 return 0;
 704
 705         for (i = 0; i < evlist->core.nr_mmaps; i++) {
 706                 int fd = evlist->overwrite_mmap[i].core.fd;
 707                 int err;
 708
 709                 if (fd < 0)
 710                         continue;
 711                 err = ioctl(fd, PERF_EVENT_IOC_PAUSE_OUTPUT, value ? 1 : 0);
 712                 if (err)
 713                         return err;
 714         }
 715         return 0;
 716 }
 717
 718 static int evlist__pause(struct evlist *evlist)
 719 {
 720         return evlist__set_paused(evlist, true);
 721 }
 722
 723 static int evlist__resume(struct evlist *evlist)
 724 {
 725         return evlist__set_paused(evlist, false);
 726 }
 727
 728 static void evlist__munmap_nofree(struct evlist *evlist)
 729 {
 730         int i;
 731
 732         if (evlist->mmap)
 733                 for (i = 0; i < evlist->core.nr_mmaps; i++)
 734                         perf_mmap__munmap(&evlist->mmap[i].core);
 735
 736         if (evlist->overwrite_mmap)
 737                 for (i = 0; i < evlist->core.nr_mmaps; i++)
 738                         perf_mmap__munmap(&evlist->overwrite_mmap[i].core);
 739 }
 740
 741 void evlist__munmap(struct evlist *evlist)
 742 {
 743         evlist__munmap_nofree(evlist);
 744         zfree(&evlist->mmap);
 745         zfree(&evlist->overwrite_mmap);
 746 }
 747
 748 static void perf_mmap__unmap_cb(struct perf_mmap *map)
 749 {
 750         struct mmap *m = container_of(map, struct mmap, core);
 751
 752         mmap__munmap(m);
 753 }
 754
 755 static struct mmap *evlist__alloc_mmap(struct evlist *evlist,
 756                                        bool overwrite)
 757 {
 758         int i;
 759         struct mmap *map;
 760
 761         map = zalloc(evlist->core.nr_mmaps * sizeof(struct mmap));
 762         if (!map)
 763                 return NULL;
 764
 765         for (i = 0; i < evlist->core.nr_mmaps; i++) {
 766                 struct perf_mmap *prev = i ? &map[i - 1].core : NULL;
 767
 768                 /*
 769                  * When the perf_mmap() call is made we grab one refcount, plus
 770                  * one extra to let perf_mmap__consume() get the last
 771                  * events after all real references (perf_mmap__get()) are
 772                  * dropped.
 773                  *
 774                  * Each PERF_EVENT_IOC_SET_OUTPUT points to this mmap and
 775                  * thus does perf_mmap__get() on it.
 776                  */
 777                 perf_mmap__init(&map[i].core, prev, overwrite, perf_mmap__unmap_cb);
 778         }
 779
 780         return map;
 781 }
 782
 783 static void
 784 perf_evlist__mmap_cb_idx(struct perf_evlist *_evlist,
 785                          struct perf_mmap_param *_mp,
 786                          int idx, bool per_cpu)
 787 {
 788         struct evlist *evlist = container_of(_evlist, struct evlist, core);
 789         struct mmap_params *mp = container_of(_mp, struct mmap_params, core);
 790
 791         auxtrace_mmap_params__set_idx(&mp->auxtrace_mp, evlist, idx, per_cpu);
 792 }
 793
 794 static struct perf_mmap*
 795 perf_evlist__mmap_cb_get(struct perf_evlist *_evlist, bool overwrite, int idx)
 796 {
 797         struct evlist *evlist = container_of(_evlist, struct evlist, core);
 798         struct mmap *maps;
 799
 800         maps = overwrite ? evlist->overwrite_mmap : evlist->mmap;
 801
 802         if (!maps) {
 803                 maps = evlist__alloc_mmap(evlist, overwrite);
 804                 if (!maps)
 805                         return NULL;
 806
 807                 if (overwrite) {
 808                         evlist->overwrite_mmap = maps;
 809                         if (evlist->bkw_mmap_state == BKW_MMAP_NOTREADY)
 810                                 evlist__toggle_bkw_mmap(evlist, BKW_MMAP_RUNNING);
 811                 } else {
 812                         evlist->mmap = maps;
 813                 }
 814         }
 815
 816         return &maps[idx].core;
 817 }
 818
 819 static int
 820 perf_evlist__mmap_cb_mmap(struct perf_mmap *_map, struct perf_mmap_param *_mp,
 821                           int output, int cpu)
 822 {
 823         struct mmap *map = container_of(_map, struct mmap, core);
 824         struct mmap_params *mp = container_of(_mp, struct mmap_params, core);
 825
 826         return mmap__mmap(map, mp, output, cpu);
 827 }
 828
 829 unsigned long perf_event_mlock_kb_in_pages(void)
 830 {
 831         unsigned long pages;
 832         int max;
 833
 834         if (sysctl__read_int("kernel/perf_event_mlock_kb", &max) < 0) {
 835                 /*
 836                  * Pick a once upon a time good value, i.e. things look
 837                  * strange since we can't read a sysctl value, but lets not
 838                  * die yet...
 839                  */
 840                 max = 512;
 841         } else {
 842                 max -= (page_size / 1024);
 843         }
 844
 845         pages = (max * 1024) / page_size;
 846         if (!is_power_of_2(pages))
 847                 pages = rounddown_pow_of_two(pages);
 848
 849         return pages;
 850 }
 851
 852 size_t evlist__mmap_size(unsigned long pages)
 853 {
 854         if (pages == UINT_MAX)
 855                 pages = perf_event_mlock_kb_in_pages();
 856         else if (!is_power_of_2(pages))
 857                 return 0;
 858
 859         return (pages + 1) * page_size;
 860 }
 861
 862 static long parse_pages_arg(const char *str, unsigned long min,
 863                             unsigned long max)
 864 {
 865         unsigned long pages, val;
 866         static struct parse_tag tags[] = {
 867                 { .tag  = 'B', .mult = 1       },
 868                 { .tag  = 'K', .mult = 1 << 10 },
 869                 { .tag  = 'M', .mult = 1 << 20 },
 870                 { .tag  = 'G', .mult = 1 << 30 },
 871                 { .tag  = 0 },
 872         };
 873
 874         if (str == NULL)
 875                 return -EINVAL;
 876
 877         val = parse_tag_value(str, tags);
 878         if (val != (unsigned long) -1) {
 879                 /* we got file size value */
 880                 pages = PERF_ALIGN(val, page_size) / page_size;
 881         } else {
 882                 /* we got pages count value */
 883                 char *eptr;
 884                 pages = strtoul(str, &eptr, 10);
 885                 if (*eptr != '\0')
 886                         return -EINVAL;
 887         }
 888
 889         if (pages == 0 && min == 0) {
 890                 /* leave number of pages at 0 */
 891         } else if (!is_power_of_2(pages)) {
 892                 char buf[100];
 893
 894                 /* round pages up to next power of 2 */
 895                 pages = roundup_pow_of_two(pages);
 896                 if (!pages)
 897                         return -EINVAL;
 898
 899                 unit_number__scnprintf(buf, sizeof(buf), pages * page_size);
 900                 pr_info("rounding mmap pages size to %s (%lu pages)\n",
 901                         buf, pages);
 902         }
 903
 904         if (pages > max)
 905                 return -EINVAL;
 906
 907         return pages;
 908 }
 909
 910 int __evlist__parse_mmap_pages(unsigned int *mmap_pages, const char *str)
 911 {
 912         unsigned long max = UINT_MAX;
 913         long pages;
 914
 915         if (max > SIZE_MAX / page_size)
 916                 max = SIZE_MAX / page_size;
 917
 918         pages = parse_pages_arg(str, 1, max);
 919         if (pages < 0) {
 920                 pr_err("Invalid argument for --mmap_pages/-m\n");
 921                 return -1;
 922         }
 923
 924         *mmap_pages = pages;
 925         return 0;
 926 }
 927
 928 int evlist__parse_mmap_pages(const struct option *opt, const char *str, int unset __maybe_unused)
 929 {
 930         return __evlist__parse_mmap_pages(opt->value, str);
 931 }
 932
 933 /**
 934  * evlist__mmap_ex - Create mmaps to receive events.
 935  * @evlist: list of events
 936  * @pages: map length in pages
 937  * @overwrite: overwrite older events?
 938  * @auxtrace_pages - auxtrace map length in pages
 939  * @auxtrace_overwrite - overwrite older auxtrace data?
 940  *
 941  * If @overwrite is %false the user needs to signal event consumption using
 942  * perf_mmap__write_tail().  Using evlist__mmap_read() does this
 943  * automatically.
 944  *
 945  * Similarly, if @auxtrace_overwrite is %false the user needs to signal data
 946  * consumption using auxtrace_mmap__write_tail().
 947  *
 948  * Return: %0 on success, negative error code otherwise.
 949  */
 950 int evlist__mmap_ex(struct evlist *evlist, unsigned int pages,
 951                          unsigned int auxtrace_pages,
 952                          bool auxtrace_overwrite, int nr_cblocks, int affinity, int flush,
 953                          int comp_level)
 954 {
 955         /*
 956          * Delay setting mp.prot: set it before calling perf_mmap__mmap.
 957          * Its value is decided by evsel's write_backward.
 958          * So &mp should not be passed through const pointer.
 959          */
 960         struct mmap_params mp = {
 961                 .nr_cblocks     = nr_cblocks,
 962                 .affinity       = affinity,
 963                 .flush          = flush,
 964                 .comp_level     = comp_level
 965         };
 966         struct perf_evlist_mmap_ops ops = {
 967                 .idx  = perf_evlist__mmap_cb_idx,
 968                 .get  = perf_evlist__mmap_cb_get,
 969                 .mmap = perf_evlist__mmap_cb_mmap,
 970         };
 971
 972         evlist->core.mmap_len = evlist__mmap_size(pages);
 973         pr_debug("mmap size %zuB\n", evlist->core.mmap_len);
 974
 975         auxtrace_mmap_params__init(&mp.auxtrace_mp, evlist->core.mmap_len,
 976                                    auxtrace_pages, auxtrace_overwrite);
 977
 978         return perf_evlist__mmap_ops(&evlist->core, &ops, &mp.core);
 979 }
 980
 981 int evlist__mmap(struct evlist *evlist, unsigned int pages)
 982 {
 983         return evlist__mmap_ex(evlist, pages, 0, false, 0, PERF_AFFINITY_SYS, 1, 0);
 984 }
 985
 986 int evlist__create_maps(struct evlist *evlist, struct target *target)
 987 {
 988         bool all_threads = (target->per_thread && target->system_wide);
 989         struct perf_cpu_map *cpus;
 990         struct perf_thread_map *threads;
 991
 992         /*
 993          * If specify '-a' and '--per-thread' to perf record, perf record
 994          * will override '--per-thread'. target->per_thread = false and
 995          * target->system_wide = true.
 996          *
 997          * If specify '--per-thread' only to perf record,
 998          * target->per_thread = true and target->system_wide = false.
 999          *
1000          * So target->per_thread && target->system_wide is false.
1001          * For perf record, thread_map__new_str doesn't call
1002          * thread_map__new_all_cpus. That will keep perf record's
1003          * current behavior.
1004          *
1005          * For perf stat, it allows the case that target->per_thread and
1006          * target->system_wide are all true. It means to collect system-wide
1007          * per-thread data. thread_map__new_str will call
1008          * thread_map__new_all_cpus to enumerate all threads.
1009          */
1010         threads = thread_map__new_str(target->pid, target->tid, target->uid,
1011                                       all_threads);
1012
1013         if (!threads)
1014                 return -1;
1015
1016         if (target__uses_dummy_map(target))
1017                 cpus = perf_cpu_map__dummy_new();
1018         else
1019                 cpus = perf_cpu_map__new(target->cpu_list);
1020
1021         if (!cpus)
1022                 goto out_delete_threads;
1023
1024         evlist->core.has_user_cpus = !!target->cpu_list;
1025
1026         perf_evlist__set_maps(&evlist->core, cpus, threads);
1027
1028         /* as evlist now has references, put count here */
1029         perf_cpu_map__put(cpus);
1030         perf_thread_map__put(threads);
1031
1032         return 0;
1033
1034 out_delete_threads:
1035         perf_thread_map__put(threads);
1036         return -1;
1037 }
1038
1039 int evlist__apply_filters(struct evlist *evlist, struct evsel **err_evsel)
1040 {
1041         struct evsel *evsel;
1042         int err = 0;
1043
1044         evlist__for_each_entry(evlist, evsel) {
1045                 if (evsel->filter == NULL)
1046                         continue;
1047
1048                 /*
1049                  * filters only work for tracepoint event, which doesn't have cpu limit.
1050                  * So evlist and evsel should always be same.
1051                  */
1052                 err = perf_evsel__apply_filter(&evsel->core, evsel->filter);
1053                 if (err) {
1054                         *err_evsel = evsel;
1055                         break;
1056                 }
1057         }
1058
1059         return err;
1060 }
1061
1062 int evlist__set_tp_filter(struct evlist *evlist, const char *filter)
1063 {
1064         struct evsel *evsel;
1065         int err = 0;
1066
1067         if (filter == NULL)
1068                 return -1;
1069
1070         evlist__for_each_entry(evlist, evsel) {
1071                 if (evsel->core.attr.type != PERF_TYPE_TRACEPOINT)
1072                         continue;
1073
1074                 err = evsel__set_filter(evsel, filter);
1075                 if (err)
1076                         break;
1077         }
1078
1079         return err;
1080 }
1081
1082 int evlist__append_tp_filter(struct evlist *evlist, const char *filter)
1083 {
1084         struct evsel *evsel;
1085         int err = 0;
1086
1087         if (filter == NULL)
1088                 return -1;
1089
1090         evlist__for_each_entry(evlist, evsel) {
1091                 if (evsel->core.attr.type != PERF_TYPE_TRACEPOINT)
1092                         continue;
1093
1094                 err = evsel__append_tp_filter(evsel, filter);
1095                 if (err)
1096                         break;
1097         }
1098
1099         return err;
1100 }
1101
1102 char *asprintf__tp_filter_pids(size_t npids, pid_t *pids)
1103 {
1104         char *filter;
1105         size_t i;
1106
1107         for (i = 0; i < npids; ++i) {
1108                 if (i == 0) {
1109                         if (asprintf(&filter, "common_pid != %d", pids[i]) < 0)
1110                                 return NULL;
1111                 } else {
1112                         char *tmp;
1113
1114                         if (asprintf(&tmp, "%s && common_pid != %d", filter, pids[i]) < 0)
1115                                 goto out_free;
1116
1117                         free(filter);
1118                         filter = tmp;
1119                 }
1120         }
1121
1122         return filter;
1123 out_free:
1124         free(filter);
1125         return NULL;
1126 }
1127
1128 int evlist__set_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *pids)
1129 {
1130         char *filter = asprintf__tp_filter_pids(npids, pids);
1131         int ret = evlist__set_tp_filter(evlist, filter);
1132
1133         free(filter);
1134         return ret;
1135 }
1136
1137 int evlist__set_tp_filter_pid(struct evlist *evlist, pid_t pid)
1138 {
1139         return evlist__set_tp_filter_pids(evlist, 1, &pid);
1140 }
1141
1142 int evlist__append_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *pids)
1143 {
1144         char *filter = asprintf__tp_filter_pids(npids, pids);
1145         int ret = evlist__append_tp_filter(evlist, filter);
1146
1147         free(filter);
1148         return ret;
1149 }
1150
1151 int evlist__append_tp_filter_pid(struct evlist *evlist, pid_t pid)
1152 {
1153         return evlist__append_tp_filter_pids(evlist, 1, &pid);
1154 }
1155
1156 bool evlist__valid_sample_type(struct evlist *evlist)
1157 {
1158         struct evsel *pos;
1159
1160         if (evlist->core.nr_entries == 1)
1161                 return true;
1162
1163         if (evlist->id_pos < 0 || evlist->is_pos < 0)
1164                 return false;
1165
1166         evlist__for_each_entry(evlist, pos) {
1167                 if (pos->id_pos != evlist->id_pos ||
1168                     pos->is_pos != evlist->is_pos)
1169                         return false;
1170         }
1171
1172         return true;
1173 }
1174
1175 u64 __evlist__combined_sample_type(struct evlist *evlist)
1176 {
1177         struct evsel *evsel;
1178
1179         if (evlist->combined_sample_type)
1180                 return evlist->combined_sample_type;
1181
1182         evlist__for_each_entry(evlist, evsel)
1183                 evlist->combined_sample_type |= evsel->core.attr.sample_type;
1184
1185         return evlist->combined_sample_type;
1186 }
1187
1188 u64 evlist__combined_sample_type(struct evlist *evlist)
1189 {
1190         evlist->combined_sample_type = 0;
1191         return __evlist__combined_sample_type(evlist);
1192 }
1193
1194 u64 evlist__combined_branch_type(struct evlist *evlist)
1195 {
1196         struct evsel *evsel;
1197         u64 branch_type = 0;
1198
1199         evlist__for_each_entry(evlist, evsel)
1200                 branch_type |= evsel->core.attr.branch_sample_type;
1201         return branch_type;
1202 }
1203
1204 bool evlist__valid_read_format(struct evlist *evlist)
1205 {
1206         struct evsel *first = evlist__first(evlist), *pos = first;
1207         u64 read_format = first->core.attr.read_format;
1208         u64 sample_type = first->core.attr.sample_type;
1209
1210         evlist__for_each_entry(evlist, pos) {
1211                 if (read_format != pos->core.attr.read_format) {
1212                         pr_debug("Read format differs %#" PRIx64 " vs %#" PRIx64 "\n",
1213                                  read_format, (u64)pos->core.attr.read_format);
1214                 }
1215         }
1216
1217         /* PERF_SAMPLE_READ implies PERF_FORMAT_ID. */
1218         if ((sample_type & PERF_SAMPLE_READ) &&
1219             !(read_format & PERF_FORMAT_ID)) {
1220                 return false;
1221         }
1222
1223         return true;
1224 }
1225
1226 u16 evlist__id_hdr_size(struct evlist *evlist)
1227 {
1228         struct evsel *first = evlist__first(evlist);
1229         struct perf_sample *data;
1230         u64 sample_type;
1231         u16 size = 0;
1232
1233         if (!first->core.attr.sample_id_all)
1234                 goto out;
1235
1236         sample_type = first->core.attr.sample_type;
1237
1238         if (sample_type & PERF_SAMPLE_TID)
1239                 size += sizeof(data->tid) * 2;
1240
1241        if (sample_type & PERF_SAMPLE_TIME)
1242                 size += sizeof(data->time);
1243
1244         if (sample_type & PERF_SAMPLE_ID)
1245                 size += sizeof(data->id);
1246
1247         if (sample_type & PERF_SAMPLE_STREAM_ID)
1248                 size += sizeof(data->stream_id);
1249
1250         if (sample_type & PERF_SAMPLE_CPU)
1251                 size += sizeof(data->cpu) * 2;
1252
1253         if (sample_type & PERF_SAMPLE_IDENTIFIER)
1254                 size += sizeof(data->id);
1255 out:
1256         return size;
1257 }
1258
1259 bool evlist__valid_sample_id_all(struct evlist *evlist)
1260 {
1261         struct evsel *first = evlist__first(evlist), *pos = first;
1262
1263         evlist__for_each_entry_continue(evlist, pos) {
1264                 if (first->core.attr.sample_id_all != pos->core.attr.sample_id_all)
1265                         return false;
1266         }
1267
1268         return true;
1269 }
1270
1271 bool evlist__sample_id_all(struct evlist *evlist)
1272 {
1273         struct evsel *first = evlist__first(evlist);
1274         return first->core.attr.sample_id_all;
1275 }
1276
1277 void evlist__set_selected(struct evlist *evlist, struct evsel *evsel)
1278 {
1279         evlist->selected = evsel;
1280 }
1281
1282 void evlist__close(struct evlist *evlist)
1283 {
1284         struct evsel *evsel;
1285         struct affinity affinity;
1286         int cpu, i;
1287
1288         /*
1289          * With perf record core.cpus is usually NULL.
1290          * Use the old method to handle this for now.
1291          */
1292         if (!evlist->core.cpus) {
1293                 evlist__for_each_entry_reverse(evlist, evsel)
1294                         evsel__close(evsel);
1295                 return;
1296         }
1297
1298         if (affinity__setup(&affinity) < 0)
1299                 return;
1300         evlist__for_each_cpu(evlist, i, cpu) {
1301                 affinity__set(&affinity, cpu);
1302
1303                 evlist__for_each_entry_reverse(evlist, evsel) {
1304                         if (evsel__cpu_iter_skip(evsel, cpu))
1305                             continue;
1306                         perf_evsel__close_cpu(&evsel->core, evsel->cpu_iter - 1);
1307                 }
1308         }
1309         affinity__cleanup(&affinity);
1310         evlist__for_each_entry_reverse(evlist, evsel) {
1311                 perf_evsel__free_fd(&evsel->core);
1312                 perf_evsel__free_id(&evsel->core);
1313         }
1314         perf_evlist__reset_id_hash(&evlist->core);
1315 }
1316
1317 static int evlist__create_syswide_maps(struct evlist *evlist)
1318 {
1319         struct perf_cpu_map *cpus;
1320         struct perf_thread_map *threads;
1321         int err = -ENOMEM;
1322
1323         /*
1324          * Try reading /sys/devices/system/cpu/online to get
1325          * an all cpus map.
1326          *
1327          * FIXME: -ENOMEM is the best we can do here, the cpu_map
1328          * code needs an overhaul to properly forward the
1329          * error, and we may not want to do that fallback to a
1330          * default cpu identity map :-\
1331          */
1332         cpus = perf_cpu_map__new(NULL);
1333         if (!cpus)
1334                 goto out;
1335
1336         threads = perf_thread_map__new_dummy();
1337         if (!threads)
1338                 goto out_put;
1339
1340         perf_evlist__set_maps(&evlist->core, cpus, threads);
1341
1342         perf_thread_map__put(threads);
1343 out_put:
1344         perf_cpu_map__put(cpus);
1345 out:
1346         return err;
1347 }
1348
1349 int evlist__open(struct evlist *evlist)
1350 {
1351         struct evsel *evsel;
1352         int err;
1353
1354         /*
1355          * Default: one fd per CPU, all threads, aka systemwide
1356          * as sys_perf_event_open(cpu = -1, thread = -1) is EINVAL
1357          */
1358         if (evlist->core.threads == NULL && evlist->core.cpus == NULL) {
1359                 err = evlist__create_syswide_maps(evlist);
1360                 if (err < 0)
1361                         goto out_err;
1362         }
1363
1364         evlist__update_id_pos(evlist);
1365
1366         evlist__for_each_entry(evlist, evsel) {
1367                 err = evsel__open(evsel, evsel->core.cpus, evsel->core.threads);
1368                 if (err < 0)
1369                         goto out_err;
1370         }
1371
1372         return 0;
1373 out_err:
1374         evlist__close(evlist);
1375         errno = -err;
1376         return err;
1377 }
1378
1379 int evlist__prepare_workload(struct evlist *evlist, struct target *target, const char *argv[],
1380                              bool pipe_output, void (*exec_error)(int signo, siginfo_t *info, void *ucontext))
1381 {
1382         int child_ready_pipe[2], go_pipe[2];
1383         char bf;
1384
1385         if (pipe(child_ready_pipe) < 0) {
1386                 perror("failed to create 'ready' pipe");
1387                 return -1;
1388         }
1389
1390         if (pipe(go_pipe) < 0) {
1391                 perror("failed to create 'go' pipe");
1392                 goto out_close_ready_pipe;
1393         }
1394
1395         evlist->workload.pid = fork();
1396         if (evlist->workload.pid < 0) {
1397                 perror("failed to fork");
1398                 goto out_close_pipes;
1399         }
1400
1401         if (!evlist->workload.pid) {
1402                 int ret;
1403
1404                 if (pipe_output)
1405                         dup2(2, 1);
1406
1407                 signal(SIGTERM, SIG_DFL);
1408
1409                 close(child_ready_pipe[0]);
1410                 close(go_pipe[1]);
1411                 fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
1412
1413                 /*
1414                  * Change the name of this process not to confuse --exclude-perf users
1415                  * that sees 'perf' in the window up to the execvp() and thinks that
1416                  * perf samples are not being excluded.
1417                  */
1418                 prctl(PR_SET_NAME, "perf-exec");
1419
1420                 /*
1421                  * Tell the parent we're ready to go
1422                  */
1423                 close(child_ready_pipe[1]);
1424
1425                 /*
1426                  * Wait until the parent tells us to go.
1427                  */
1428                 ret = read(go_pipe[0], &bf, 1);
1429                 /*
1430                  * The parent will ask for the execvp() to be performed by
1431                  * writing exactly one byte, in workload.cork_fd, usually via
1432                  * evlist__start_workload().
1433                  *
1434                  * For cancelling the workload without actually running it,
1435                  * the parent will just close workload.cork_fd, without writing
1436                  * anything, i.e. read will return zero and we just exit()
1437                  * here.
1438                  */
1439                 if (ret != 1) {
1440                         if (ret == -1)
1441                                 perror("unable to read pipe");
1442                         exit(ret);
1443                 }
1444
1445                 execvp(argv[0], (char **)argv);
1446
1447                 if (exec_error) {
1448                         union sigval val;
1449
1450                         val.sival_int = errno;
1451                         if (sigqueue(getppid(), SIGUSR1, val))
1452                                 perror(argv[0]);
1453                 } else
1454                         perror(argv[0]);
1455                 exit(-1);
1456         }
1457
1458         if (exec_error) {
1459                 struct sigaction act = {
1460                         .sa_flags     = SA_SIGINFO,
1461                         .sa_sigaction = exec_error,
1462                 };
1463                 sigaction(SIGUSR1, &act, NULL);
1464         }
1465
1466         if (target__none(target)) {
1467                 if (evlist->core.threads == NULL) {
1468                         fprintf(stderr, "FATAL: evlist->threads need to be set at this point (%s:%d).\n",
1469                                 __func__, __LINE__);
1470                         goto out_close_pipes;
1471                 }
1472                 perf_thread_map__set_pid(evlist->core.threads, 0, evlist->workload.pid);
1473         }
1474
1475         close(child_ready_pipe[1]);
1476         close(go_pipe[0]);
1477         /*
1478          * wait for child to settle
1479          */
1480         if (read(child_ready_pipe[0], &bf, 1) == -1) {
1481                 perror("unable to read pipe");
1482                 goto out_close_pipes;
1483         }
1484
1485         fcntl(go_pipe[1], F_SETFD, FD_CLOEXEC);
1486         evlist->workload.cork_fd = go_pipe[1];
1487         close(child_ready_pipe[0]);
1488         return 0;
1489
1490 out_close_pipes:
1491         close(go_pipe[0]);
1492         close(go_pipe[1]);
1493 out_close_ready_pipe:
1494         close(child_ready_pipe[0]);
1495         close(child_ready_pipe[1]);
1496         return -1;
1497 }
1498
1499 int evlist__start_workload(struct evlist *evlist)
1500 {
1501         if (evlist->workload.cork_fd > 0) {
1502                 char bf = 0;
1503                 int ret;
1504                 /*
1505                  * Remove the cork, let it rip!
1506                  */
1507                 ret = write(evlist->workload.cork_fd, &bf, 1);
1508                 if (ret < 0)
1509                         perror("unable to write to pipe");
1510
1511                 close(evlist->workload.cork_fd);
1512                 return ret;
1513         }
1514
1515         return 0;
1516 }
1517
1518 int evlist__parse_sample(struct evlist *evlist, union perf_event *event, struct perf_sample *sample)
1519 {
1520         struct evsel *evsel = evlist__event2evsel(evlist, event);
1521
1522         if (!evsel)
1523                 return -EFAULT;
1524         return evsel__parse_sample(evsel, event, sample);
1525 }
1526
1527 int evlist__parse_sample_timestamp(struct evlist *evlist, union perf_event *event, u64 *timestamp)
1528 {
1529         struct evsel *evsel = evlist__event2evsel(evlist, event);
1530
1531         if (!evsel)
1532                 return -EFAULT;
1533         return evsel__parse_sample_timestamp(evsel, event, timestamp);
1534 }
1535
1536 int evlist__strerror_open(struct evlist *evlist, int err, char *buf, size_t size)
1537 {
1538         int printed, value;
1539         char sbuf[STRERR_BUFSIZE], *emsg = str_error_r(err, sbuf, sizeof(sbuf));
1540
1541         switch (err) {
1542         case EACCES:
1543         case EPERM:
1544                 printed = scnprintf(buf, size,
1545                                     "Error:\t%s.\n"
1546                                     "Hint:\tCheck /proc/sys/kernel/perf_event_paranoid setting.", emsg);
1547
1548                 value = perf_event_paranoid();
1549
1550                 printed += scnprintf(buf + printed, size - printed, "\nHint:\t");
1551
1552                 if (value >= 2) {
1553                         printed += scnprintf(buf + printed, size - printed,
1554                                              "For your workloads it needs to be <= 1\nHint:\t");
1555                 }
1556                 printed += scnprintf(buf + printed, size - printed,
1557                                      "For system wide tracing it needs to be set to -1.\n");
1558
1559                 printed += scnprintf(buf + printed, size - printed,
1560                                     "Hint:\tTry: 'sudo sh -c \"echo -1 > /proc/sys/kernel/perf_event_paranoid\"'\n"
1561                                     "Hint:\tThe current value is %d.", value);
1562                 break;
1563         case EINVAL: {
1564                 struct evsel *first = evlist__first(evlist);
1565                 int max_freq;
1566
1567                 if (sysctl__read_int("kernel/perf_event_max_sample_rate", &max_freq) < 0)
1568                         goto out_default;
1569
1570                 if (first->core.attr.sample_freq < (u64)max_freq)
1571                         goto out_default;
1572
1573                 printed = scnprintf(buf, size,
1574                                     "Error:\t%s.\n"
1575                                     "Hint:\tCheck /proc/sys/kernel/perf_event_max_sample_rate.\n"
1576                                     "Hint:\tThe current value is %d and %" PRIu64 " is being requested.",
1577                                     emsg, max_freq, first->core.attr.sample_freq);
1578                 break;
1579         }
1580         default:
1581 out_default:
1582                 scnprintf(buf, size, "%s", emsg);
1583                 break;
1584         }
1585
1586         return 0;
1587 }
1588
1589 int evlist__strerror_mmap(struct evlist *evlist, int err, char *buf, size_t size)
1590 {
1591         char sbuf[STRERR_BUFSIZE], *emsg = str_error_r(err, sbuf, sizeof(sbuf));
1592         int pages_attempted = evlist->core.mmap_len / 1024, pages_max_per_user, printed = 0;
1593
1594         switch (err) {
1595         case EPERM:
1596                 sysctl__read_int("kernel/perf_event_mlock_kb", &pages_max_per_user);
1597                 printed += scnprintf(buf + printed, size - printed,
1598                                      "Error:\t%s.\n"
1599                                      "Hint:\tCheck /proc/sys/kernel/perf_event_mlock_kb (%d kB) setting.\n"
1600                                      "Hint:\tTried using %zd kB.\n",
1601                                      emsg, pages_max_per_user, pages_attempted);
1602
1603                 if (pages_attempted >= pages_max_per_user) {
1604                         printed += scnprintf(buf + printed, size - printed,
1605                                              "Hint:\tTry 'sudo sh -c \"echo %d > /proc/sys/kernel/perf_event_mlock_kb\"', or\n",
1606                                              pages_max_per_user + pages_attempted);
1607                 }
1608
1609                 printed += scnprintf(buf + printed, size - printed,
1610                                      "Hint:\tTry using a smaller -m/--mmap-pages value.");
1611                 break;
1612         default:
1613                 scnprintf(buf, size, "%s", emsg);
1614                 break;
1615         }
1616
1617         return 0;
1618 }
1619
1620 void evlist__to_front(struct evlist *evlist, struct evsel *move_evsel)
1621 {
1622         struct evsel *evsel, *n;
1623         LIST_HEAD(move);
1624
1625         if (move_evsel == evlist__first(evlist))
1626                 return;
1627
1628         evlist__for_each_entry_safe(evlist, n, evsel) {
1629                 if (evsel->leader == move_evsel->leader)
1630                         list_move_tail(&evsel->core.node, &move);
1631         }
1632
1633         list_splice(&move, &evlist->core.entries);
1634 }
1635
1636 struct evsel *evlist__get_tracking_event(struct evlist *evlist)
1637 {
1638         struct evsel *evsel;
1639
1640         evlist__for_each_entry(evlist, evsel) {
1641                 if (evsel->tracking)
1642                         return evsel;
1643         }
1644
1645         return evlist__first(evlist);
1646 }
1647
1648 void evlist__set_tracking_event(struct evlist *evlist, struct evsel *tracking_evsel)
1649 {
1650         struct evsel *evsel;
1651
1652         if (tracking_evsel->tracking)
1653                 return;
1654
1655         evlist__for_each_entry(evlist, evsel) {
1656                 if (evsel != tracking_evsel)
1657                         evsel->tracking = false;
1658         }
1659
1660         tracking_evsel->tracking = true;
1661 }
1662
1663 struct evsel *evlist__find_evsel_by_str(struct evlist *evlist, const char *str)
1664 {
1665         struct evsel *evsel;
1666
1667         evlist__for_each_entry(evlist, evsel) {
1668                 if (!evsel->name)
1669                         continue;
1670                 if (strcmp(str, evsel->name) == 0)
1671                         return evsel;
1672         }
1673
1674         return NULL;
1675 }
1676
1677 void evlist__toggle_bkw_mmap(struct evlist *evlist, enum bkw_mmap_state state)
1678 {
1679         enum bkw_mmap_state old_state = evlist->bkw_mmap_state;
1680         enum action {
1681                 NONE,
1682                 PAUSE,
1683                 RESUME,
1684         } action = NONE;
1685
1686         if (!evlist->overwrite_mmap)
1687                 return;
1688
1689         switch (old_state) {
1690         case BKW_MMAP_NOTREADY: {
1691                 if (state != BKW_MMAP_RUNNING)
1692                         goto state_err;
1693                 break;
1694         }
1695         case BKW_MMAP_RUNNING: {
1696                 if (state != BKW_MMAP_DATA_PENDING)
1697                         goto state_err;
1698                 action = PAUSE;
1699                 break;
1700         }
1701         case BKW_MMAP_DATA_PENDING: {
1702                 if (state != BKW_MMAP_EMPTY)
1703                         goto state_err;
1704                 break;
1705         }
1706         case BKW_MMAP_EMPTY: {
1707                 if (state != BKW_MMAP_RUNNING)
1708                         goto state_err;
1709                 action = RESUME;
1710                 break;
1711         }
1712         default:
1713                 WARN_ONCE(1, "Shouldn't get there\n");
1714         }
1715
1716         evlist->bkw_mmap_state = state;
1717
1718         switch (action) {
1719         case PAUSE:
1720                 evlist__pause(evlist);
1721                 break;
1722         case RESUME:
1723                 evlist__resume(evlist);
1724                 break;
1725         case NONE:
1726         default:
1727                 break;
1728         }
1729
1730 state_err:
1731         return;
1732 }
1733
1734 bool evlist__exclude_kernel(struct evlist *evlist)
1735 {
1736         struct evsel *evsel;
1737
1738         evlist__for_each_entry(evlist, evsel) {
1739                 if (!evsel->core.attr.exclude_kernel)
1740                         return false;
1741         }
1742
1743         return true;
1744 }
1745
1746 /*
1747  * Events in data file are not collect in groups, but we still want
1748  * the group display. Set the artificial group and set the leader's
1749  * forced_leader flag to notify the display code.
1750  */
1751 void evlist__force_leader(struct evlist *evlist)
1752 {
1753         if (!evlist->nr_groups) {
1754                 struct evsel *leader = evlist__first(evlist);
1755
1756                 evlist__set_leader(evlist);
1757                 leader->forced_leader = true;
1758         }
1759 }
1760
1761 struct evsel *evlist__reset_weak_group(struct evlist *evsel_list, struct evsel *evsel, bool close)
1762 {
1763         struct evsel *c2, *leader;
1764         bool is_open = true;
1765
1766         leader = evsel->leader;
1767         pr_debug("Weak group for %s/%d failed\n",
1768                         leader->name, leader->core.nr_members);
1769
1770         /*
1771          * for_each_group_member doesn't work here because it doesn't
1772          * include the first entry.
1773          */
1774         evlist__for_each_entry(evsel_list, c2) {
1775                 if (c2 == evsel)
1776                         is_open = false;
1777                 if (c2->leader == leader) {
1778                         if (is_open && close)
1779                                 perf_evsel__close(&c2->core);
1780                         c2->leader = c2;
1781                         c2->core.nr_members = 0;
1782                         /*
1783                          * Set this for all former members of the group
1784                          * to indicate they get reopened.
1785                          */
1786                         c2->reset_group = true;
1787                 }
1788         }
1789         return leader;
1790 }
1791
1792 static int evlist__parse_control_fifo(const char *str, int *ctl_fd, int *ctl_fd_ack, bool *ctl_fd_close)
1793 {
1794         char *s, *p;
1795         int ret = 0, fd;
1796
1797         if (strncmp(str, "fifo:", 5))
1798                 return -EINVAL;
1799
1800         str += 5;
1801         if (!*str || *str == ',')
1802                 return -EINVAL;
1803
1804         s = strdup(str);
1805         if (!s)
1806                 return -ENOMEM;
1807
1808         p = strchr(s, ',');
1809         if (p)
1810                 *p = '\0';
1811
1812         /*
1813          * O_RDWR avoids POLLHUPs which is necessary to allow the other
1814          * end of a FIFO to be repeatedly opened and closed.
1815          */
1816         fd = open(s, O_RDWR | O_NONBLOCK | O_CLOEXEC);
1817         if (fd < 0) {
1818                 pr_err("Failed to open '%s'\n", s);
1819                 ret = -errno;
1820                 goto out_free;
1821         }
1822         *ctl_fd = fd;
1823         *ctl_fd_close = true;
1824
1825         if (p && *++p) {
1826                 /* O_RDWR | O_NONBLOCK means the other end need not be open */
1827                 fd = open(p, O_RDWR | O_NONBLOCK | O_CLOEXEC);
1828                 if (fd < 0) {
1829                         pr_err("Failed to open '%s'\n", p);
1830                         ret = -errno;
1831                         goto out_free;
1832                 }
1833                 *ctl_fd_ack = fd;
1834         }
1835
1836 out_free:
1837         free(s);
1838         return ret;
1839 }
1840
1841 int evlist__parse_control(const char *str, int *ctl_fd, int *ctl_fd_ack, bool *ctl_fd_close)
1842 {
1843         char *comma = NULL, *endptr = NULL;
1844
1845         *ctl_fd_close = false;
1846
1847         if (strncmp(str, "fd:", 3))
1848                 return evlist__parse_control_fifo(str, ctl_fd, ctl_fd_ack, ctl_fd_close);
1849
1850         *ctl_fd = strtoul(&str[3], &endptr, 0);
1851         if (endptr == &str[3])
1852                 return -EINVAL;
1853
1854         comma = strchr(str, ',');
1855         if (comma) {
1856                 if (endptr != comma)
1857                         return -EINVAL;
1858
1859                 *ctl_fd_ack = strtoul(comma + 1, &endptr, 0);
1860                 if (endptr == comma + 1 || *endptr != '\0')
1861                         return -EINVAL;
1862         }
1863
1864         return 0;
1865 }
1866
1867 void evlist__close_control(int ctl_fd, int ctl_fd_ack, bool *ctl_fd_close)
1868 {
1869         if (*ctl_fd_close) {
1870                 *ctl_fd_close = false;
1871                 close(ctl_fd);
1872                 if (ctl_fd_ack >= 0)
1873                         close(ctl_fd_ack);
1874         }
1875 }
1876
1877 int evlist__initialize_ctlfd(struct evlist *evlist, int fd, int ack)
1878 {
1879         if (fd == -1) {
1880                 pr_debug("Control descriptor is not initialized\n");
1881                 return 0;
1882         }
1883
1884         evlist->ctl_fd.pos = perf_evlist__add_pollfd(&evlist->core, fd, NULL, POLLIN,
1885                                                      fdarray_flag__nonfilterable);
1886         if (evlist->ctl_fd.pos < 0) {
1887                 evlist->ctl_fd.pos = -1;
1888                 pr_err("Failed to add ctl fd entry: %m\n");
1889                 return -1;
1890         }
1891
1892         evlist->ctl_fd.fd = fd;
1893         evlist->ctl_fd.ack = ack;
1894
1895         return 0;
1896 }
1897
1898 bool evlist__ctlfd_initialized(struct evlist *evlist)
1899 {
1900         return evlist->ctl_fd.pos >= 0;
1901 }
1902
1903 int evlist__finalize_ctlfd(struct evlist *evlist)
1904 {
1905         struct pollfd *entries = evlist->core.pollfd.entries;
1906
1907         if (!evlist__ctlfd_initialized(evlist))
1908                 return 0;
1909
1910         entries[evlist->ctl_fd.pos].fd = -1;
1911         entries[evlist->ctl_fd.pos].events = 0;
1912         entries[evlist->ctl_fd.pos].revents = 0;
1913
1914         evlist->ctl_fd.pos = -1;
1915         evlist->ctl_fd.ack = -1;
1916         evlist->ctl_fd.fd = -1;
1917
1918         return 0;
1919 }
1920
1921 static int evlist__ctlfd_recv(struct evlist *evlist, enum evlist_ctl_cmd *cmd,
1922                               char *cmd_data, size_t data_size)
1923 {
1924         int err;
1925         char c;
1926         size_t bytes_read = 0;
1927
1928         *cmd = EVLIST_CTL_CMD_UNSUPPORTED;
1929         memset(cmd_data, 0, data_size);
1930         data_size--;
1931
1932         do {
1933                 err = read(evlist->ctl_fd.fd, &c, 1);
1934                 if (err > 0) {
1935                         if (c == '\n' || c == '\0')
1936                                 break;
1937                         cmd_data[bytes_read++] = c;
1938                         if (bytes_read == data_size)
1939                                 break;
1940                         continue;
1941                 } else if (err == -1) {
1942                         if (errno == EINTR)
1943                                 continue;
1944                         if (errno == EAGAIN || errno == EWOULDBLOCK)
1945                                 err = 0;
1946                         else
1947                                 pr_err("Failed to read from ctlfd %d: %m\n", evlist->ctl_fd.fd);
1948                 }
1949                 break;
1950         } while (1);
1951
1952         pr_debug("Message from ctl_fd: \"%s%s\"\n", cmd_data,
1953                  bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0");
1954
1955         if (bytes_read > 0) {
1956                 if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG,
1957                              (sizeof(EVLIST_CTL_CMD_ENABLE_TAG)-1))) {
1958                         *cmd = EVLIST_CTL_CMD_ENABLE;
1959                 } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG,
1960                                     (sizeof(EVLIST_CTL_CMD_DISABLE_TAG)-1))) {
1961                         *cmd = EVLIST_CTL_CMD_DISABLE;
1962                 } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_SNAPSHOT_TAG,
1963                                     (sizeof(EVLIST_CTL_CMD_SNAPSHOT_TAG)-1))) {
1964                         *cmd = EVLIST_CTL_CMD_SNAPSHOT;
1965                         pr_debug("is snapshot\n");
1966                 } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_EVLIST_TAG,
1967                                     (sizeof(EVLIST_CTL_CMD_EVLIST_TAG)-1))) {
1968                         *cmd = EVLIST_CTL_CMD_EVLIST;
1969                 } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_STOP_TAG,
1970                                     (sizeof(EVLIST_CTL_CMD_STOP_TAG)-1))) {
1971                         *cmd = EVLIST_CTL_CMD_STOP;
1972                 } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_PING_TAG,
1973                                     (sizeof(EVLIST_CTL_CMD_PING_TAG)-1))) {
1974                         *cmd = EVLIST_CTL_CMD_PING;
1975                 }
1976         }
1977
1978         return bytes_read ? (int)bytes_read : err;
1979 }
1980
1981 int evlist__ctlfd_ack(struct evlist *evlist)
1982 {
1983         int err;
1984
1985         if (evlist->ctl_fd.ack == -1)
1986                 return 0;
1987
1988         err = write(evlist->ctl_fd.ack, EVLIST_CTL_CMD_ACK_TAG,
1989                     sizeof(EVLIST_CTL_CMD_ACK_TAG));
1990         if (err == -1)
1991                 pr_err("failed to write to ctl_ack_fd %d: %m\n", evlist->ctl_fd.ack);
1992
1993         return err;
1994 }
1995
1996 static int get_cmd_arg(char *cmd_data, size_t cmd_size, char **arg)
1997 {
1998         char *data = cmd_data + cmd_size;
1999
2000         /* no argument */
2001         if (!*data)
2002                 return 0;
2003
2004         /* there's argument */
2005         if (*data == ' ') {
2006                 *arg = data + 1;
2007                 return 1;
2008         }
2009
2010         /* malformed */
2011         return -1;
2012 }
2013
2014 static int evlist__ctlfd_enable(struct evlist *evlist, char *cmd_data, bool enable)
2015 {
2016         struct evsel *evsel;
2017         char *name;
2018         int err;
2019
2020         err = get_cmd_arg(cmd_data,
2021                           enable ? sizeof(EVLIST_CTL_CMD_ENABLE_TAG) - 1 :
2022                                    sizeof(EVLIST_CTL_CMD_DISABLE_TAG) - 1,
2023                           &name);
2024         if (err < 0) {
2025                 pr_info("failed: wrong command\n");
2026                 return -1;
2027         }
2028
2029         if (err) {
2030                 evsel = evlist__find_evsel_by_str(evlist, name);
2031                 if (evsel) {
2032                         if (enable)
2033                                 evlist__enable_evsel(evlist, name);
2034                         else
2035                                 evlist__disable_evsel(evlist, name);
2036                         pr_info("Event %s %s\n", evsel->name,
2037                                 enable ? "enabled" : "disabled");
2038                 } else {
2039                         pr_info("failed: can't find '%s' event\n", name);
2040                 }
2041         } else {
2042                 if (enable) {
2043                         evlist__enable(evlist);
2044                         pr_info(EVLIST_ENABLED_MSG);
2045                 } else {
2046                         evlist__disable(evlist);
2047                         pr_info(EVLIST_DISABLED_MSG);
2048                 }
2049         }
2050
2051         return 0;
2052 }
2053
2054 static int evlist__ctlfd_list(struct evlist *evlist, char *cmd_data)
2055 {
2056         struct perf_attr_details details = { .verbose = false, };
2057         struct evsel *evsel;
2058         char *arg;
2059         int err;
2060
2061         err = get_cmd_arg(cmd_data,
2062                           sizeof(EVLIST_CTL_CMD_EVLIST_TAG) - 1,
2063                           &arg);
2064         if (err < 0) {
2065                 pr_info("failed: wrong command\n");
2066                 return -1;
2067         }
2068
2069         if (err) {
2070                 if (!strcmp(arg, "-v")) {
2071                         details.verbose = true;
2072                 } else if (!strcmp(arg, "-g")) {
2073                         details.event_group = true;
2074                 } else if (!strcmp(arg, "-F")) {
2075                         details.freq = true;
2076                 } else {
2077                         pr_info("failed: wrong command\n");
2078                         return -1;
2079                 }
2080         }
2081
2082         evlist__for_each_entry(evlist, evsel)
2083                 evsel__fprintf(evsel, &details, stderr);
2084
2085         return 0;
2086 }
2087
2088 int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd)
2089 {
2090         int err = 0;
2091         char cmd_data[EVLIST_CTL_CMD_MAX_LEN];
2092         int ctlfd_pos = evlist->ctl_fd.pos;
2093         struct pollfd *entries = evlist->core.pollfd.entries;
2094
2095         if (!evlist__ctlfd_initialized(evlist) || !entries[ctlfd_pos].revents)
2096                 return 0;
2097
2098         if (entries[ctlfd_pos].revents & POLLIN) {
2099                 err = evlist__ctlfd_recv(evlist, cmd, cmd_data,
2100                                          EVLIST_CTL_CMD_MAX_LEN);
2101                 if (err > 0) {
2102                         switch (*cmd) {
2103                         case EVLIST_CTL_CMD_ENABLE:
2104                         case EVLIST_CTL_CMD_DISABLE:
2105                                 err = evlist__ctlfd_enable(evlist, cmd_data,
2106                                                            *cmd == EVLIST_CTL_CMD_ENABLE);
2107                                 break;
2108                         case EVLIST_CTL_CMD_EVLIST:
2109                                 err = evlist__ctlfd_list(evlist, cmd_data);
2110                                 break;
2111                         case EVLIST_CTL_CMD_SNAPSHOT:
2112                         case EVLIST_CTL_CMD_STOP:
2113                         case EVLIST_CTL_CMD_PING:
2114                                 break;
2115                         case EVLIST_CTL_CMD_ACK:
2116                         case EVLIST_CTL_CMD_UNSUPPORTED:
2117                         default:
2118                                 pr_debug("ctlfd: unsupported %d\n", *cmd);
2119                                 break;
2120                         }
2121                         if (!(*cmd == EVLIST_CTL_CMD_ACK || *cmd == EVLIST_CTL_CMD_UNSUPPORTED ||
2122                               *cmd == EVLIST_CTL_CMD_SNAPSHOT))
2123                                 evlist__ctlfd_ack(evlist);
2124                 }
2125         }
2126
2127         if (entries[ctlfd_pos].revents & (POLLHUP | POLLERR))
2128                 evlist__finalize_ctlfd(evlist);
2129         else
2130                 entries[ctlfd_pos].revents = 0;
2131
2132         return err;
2133 }
2134
2135 struct evsel *evlist__find_evsel(struct evlist *evlist, int idx)
2136 {
2137         struct evsel *evsel;
2138
2139         evlist__for_each_entry(evlist, evsel) {
2140                 if (evsel->idx == idx)
2141                         return evsel;
2142         }
2143         return NULL;
2144 }
2145
2146 int evlist__scnprintf_evsels(struct evlist *evlist, size_t size, char *bf)
2147 {
2148         struct evsel *evsel;
2149         int printed = 0;
2150
2151         evlist__for_each_entry(evlist, evsel) {
2152                 if (evsel__is_dummy_event(evsel))
2153                         continue;
2154                 if (size > (strlen(evsel__name(evsel)) + (printed ? 2 : 1))) {
2155                         printed += scnprintf(bf + printed, size - printed, "%s%s", printed ? "," : "", evsel__name(evsel));
2156                 } else {
2157                         printed += scnprintf(bf + printed, size - printed, "%s...", printed ? "," : "");
2158                         break;
2159                 }
2160         }
2161
2162         return printed;
2163 }