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         evlist__for_each_entry(evlist, pos)
 429                 bpf_counter__disable(pos);
 430
 431         /* Disable 'immediate' events last */
 432         for (imm = 0; imm <= 1; imm++) {
 433                 evlist__for_each_cpu(evlist, i, cpu) {
 434                         affinity__set(&affinity, cpu);
 435
 436                         evlist__for_each_entry(evlist, pos) {
 437                                 if (evsel__strcmp(pos, evsel_name))
 438                                         continue;
 439                                 if (evsel__cpu_iter_skip(pos, cpu))
 440                                         continue;
 441                                 if (pos->disabled || !evsel__is_group_leader(pos) || !pos->core.fd)
 442                                         continue;
 443                                 if (pos->immediate)
 444                                         has_imm = true;
 445                                 if (pos->immediate != imm)
 446                                         continue;
 447                                 evsel__disable_cpu(pos, pos->cpu_iter - 1);
 448                         }
 449                 }
 450                 if (!has_imm)
 451                         break;
 452         }
 453
 454         affinity__cleanup(&affinity);
 455         evlist__for_each_entry(evlist, pos) {
 456                 if (evsel__strcmp(pos, evsel_name))
 457                         continue;
 458                 if (!evsel__is_group_leader(pos) || !pos->core.fd)
 459                         continue;
 460                 pos->disabled = true;
 461         }
 462
 463         /*
 464          * If we disabled only single event, we need to check
 465          * the enabled state of the evlist manually.
 466          */
 467         if (evsel_name)
 468                 evlist->enabled = evlist__is_enabled(evlist);
 469         else
 470                 evlist->enabled = false;
 471 }
 472
 473 void evlist__disable(struct evlist *evlist)
 474 {
 475         __evlist__disable(evlist, NULL);
 476 }
 477
 478 void evlist__disable_evsel(struct evlist *evlist, char *evsel_name)
 479 {
 480         __evlist__disable(evlist, evsel_name);
 481 }
 482
 483 static void __evlist__enable(struct evlist *evlist, char *evsel_name)
 484 {
 485         struct evsel *pos;
 486         struct affinity affinity;
 487         int cpu, i;
 488
 489         if (affinity__setup(&affinity) < 0)
 490                 return;
 491
 492         evlist__for_each_cpu(evlist, i, cpu) {
 493                 affinity__set(&affinity, cpu);
 494
 495                 evlist__for_each_entry(evlist, pos) {
 496                         if (evsel__strcmp(pos, evsel_name))
 497                                 continue;
 498                         if (evsel__cpu_iter_skip(pos, cpu))
 499                                 continue;
 500                         if (!evsel__is_group_leader(pos) || !pos->core.fd)
 501                                 continue;
 502                         evsel__enable_cpu(pos, pos->cpu_iter - 1);
 503                 }
 504         }
 505         affinity__cleanup(&affinity);
 506         evlist__for_each_entry(evlist, pos) {
 507                 if (evsel__strcmp(pos, evsel_name))
 508                         continue;
 509                 if (!evsel__is_group_leader(pos) || !pos->core.fd)
 510                         continue;
 511                 pos->disabled = false;
 512         }
 513
 514         /*
 515          * Even single event sets the 'enabled' for evlist,
 516          * so the toggle can work properly and toggle to
 517          * 'disabled' state.
 518          */
 519         evlist->enabled = true;
 520 }
 521
 522 void evlist__enable(struct evlist *evlist)
 523 {
 524         __evlist__enable(evlist, NULL);
 525 }
 526
 527 void evlist__enable_evsel(struct evlist *evlist, char *evsel_name)
 528 {
 529         __evlist__enable(evlist, evsel_name);
 530 }
 531
 532 void evlist__toggle_enable(struct evlist *evlist)
 533 {
 534         (evlist->enabled ? evlist__disable : evlist__enable)(evlist);
 535 }
 536
 537 static int evlist__enable_event_cpu(struct evlist *evlist, struct evsel *evsel, int cpu)
 538 {
 539         int thread;
 540         int nr_threads = evlist__nr_threads(evlist, evsel);
 541
 542         if (!evsel->core.fd)
 543                 return -EINVAL;
 544
 545         for (thread = 0; thread < nr_threads; thread++) {
 546                 int err = ioctl(FD(evsel, cpu, thread), PERF_EVENT_IOC_ENABLE, 0);
 547                 if (err)
 548                         return err;
 549         }
 550         return 0;
 551 }
 552
 553 static int evlist__enable_event_thread(struct evlist *evlist, struct evsel *evsel, int thread)
 554 {
 555         int cpu;
 556         int nr_cpus = perf_cpu_map__nr(evlist->core.cpus);
 557
 558         if (!evsel->core.fd)
 559                 return -EINVAL;
 560
 561         for (cpu = 0; cpu < nr_cpus; cpu++) {
 562                 int err = ioctl(FD(evsel, cpu, thread), PERF_EVENT_IOC_ENABLE, 0);
 563                 if (err)
 564                         return err;
 565         }
 566         return 0;
 567 }
 568
 569 int evlist__enable_event_idx(struct evlist *evlist, struct evsel *evsel, int idx)
 570 {
 571         bool per_cpu_mmaps = !perf_cpu_map__empty(evlist->core.cpus);
 572
 573         if (per_cpu_mmaps)
 574                 return evlist__enable_event_cpu(evlist, evsel, idx);
 575
 576         return evlist__enable_event_thread(evlist, evsel, idx);
 577 }
 578
 579 int evlist__add_pollfd(struct evlist *evlist, int fd)
 580 {
 581         return perf_evlist__add_pollfd(&evlist->core, fd, NULL, POLLIN, fdarray_flag__default);
 582 }
 583
 584 int evlist__filter_pollfd(struct evlist *evlist, short revents_and_mask)
 585 {
 586         return perf_evlist__filter_pollfd(&evlist->core, revents_and_mask);
 587 }
 588
 589 #ifdef HAVE_EVENTFD_SUPPORT
 590 int evlist__add_wakeup_eventfd(struct evlist *evlist, int fd)
 591 {
 592         return perf_evlist__add_pollfd(&evlist->core, fd, NULL, POLLIN,
 593                                        fdarray_flag__nonfilterable);
 594 }
 595 #endif
 596
 597 int evlist__poll(struct evlist *evlist, int timeout)
 598 {
 599         return perf_evlist__poll(&evlist->core, timeout);
 600 }
 601
 602 struct perf_sample_id *evlist__id2sid(struct evlist *evlist, u64 id)
 603 {
 604         struct hlist_head *head;
 605         struct perf_sample_id *sid;
 606         int hash;
 607
 608         hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
 609         head = &evlist->core.heads[hash];
 610
 611         hlist_for_each_entry(sid, head, node)
 612                 if (sid->id == id)
 613                         return sid;
 614
 615         return NULL;
 616 }
 617
 618 struct evsel *evlist__id2evsel(struct evlist *evlist, u64 id)
 619 {
 620         struct perf_sample_id *sid;
 621
 622         if (evlist->core.nr_entries == 1 || !id)
 623                 return evlist__first(evlist);
 624
 625         sid = evlist__id2sid(evlist, id);
 626         if (sid)
 627                 return container_of(sid->evsel, struct evsel, core);
 628
 629         if (!evlist__sample_id_all(evlist))
 630                 return evlist__first(evlist);
 631
 632         return NULL;
 633 }
 634
 635 struct evsel *evlist__id2evsel_strict(struct evlist *evlist, u64 id)
 636 {
 637         struct perf_sample_id *sid;
 638
 639         if (!id)
 640                 return NULL;
 641
 642         sid = evlist__id2sid(evlist, id);
 643         if (sid)
 644                 return container_of(sid->evsel, struct evsel, core);
 645
 646         return NULL;
 647 }
 648
 649 static int evlist__event2id(struct evlist *evlist, union perf_event *event, u64 *id)
 650 {
 651         const __u64 *array = event->sample.array;
 652         ssize_t n;
 653
 654         n = (event->header.size - sizeof(event->header)) >> 3;
 655
 656         if (event->header.type == PERF_RECORD_SAMPLE) {
 657                 if (evlist->id_pos >= n)
 658                         return -1;
 659                 *id = array[evlist->id_pos];
 660         } else {
 661                 if (evlist->is_pos > n)
 662                         return -1;
 663                 n -= evlist->is_pos;
 664                 *id = array[n];
 665         }
 666         return 0;
 667 }
 668
 669 struct evsel *evlist__event2evsel(struct evlist *evlist, union perf_event *event)
 670 {
 671         struct evsel *first = evlist__first(evlist);
 672         struct hlist_head *head;
 673         struct perf_sample_id *sid;
 674         int hash;
 675         u64 id;
 676
 677         if (evlist->core.nr_entries == 1)
 678                 return first;
 679
 680         if (!first->core.attr.sample_id_all &&
 681             event->header.type != PERF_RECORD_SAMPLE)
 682                 return first;
 683
 684         if (evlist__event2id(evlist, event, &id))
 685                 return NULL;
 686
 687         /* Synthesized events have an id of zero */
 688         if (!id)
 689                 return first;
 690
 691         hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
 692         head = &evlist->core.heads[hash];
 693
 694         hlist_for_each_entry(sid, head, node) {
 695                 if (sid->id == id)
 696                         return container_of(sid->evsel, struct evsel, core);
 697         }
 698         return NULL;
 699 }
 700
 701 static int evlist__set_paused(struct evlist *evlist, bool value)
 702 {
 703         int i;
 704
 705         if (!evlist->overwrite_mmap)
 706                 return 0;
 707
 708         for (i = 0; i < evlist->core.nr_mmaps; i++) {
 709                 int fd = evlist->overwrite_mmap[i].core.fd;
 710                 int err;
 711
 712                 if (fd < 0)
 713                         continue;
 714                 err = ioctl(fd, PERF_EVENT_IOC_PAUSE_OUTPUT, value ? 1 : 0);
 715                 if (err)
 716                         return err;
 717         }
 718         return 0;
 719 }
 720
 721 static int evlist__pause(struct evlist *evlist)
 722 {
 723         return evlist__set_paused(evlist, true);
 724 }
 725
 726 static int evlist__resume(struct evlist *evlist)
 727 {
 728         return evlist__set_paused(evlist, false);
 729 }
 730
 731 static void evlist__munmap_nofree(struct evlist *evlist)
 732 {
 733         int i;
 734
 735         if (evlist->mmap)
 736                 for (i = 0; i < evlist->core.nr_mmaps; i++)
 737                         perf_mmap__munmap(&evlist->mmap[i].core);
 738
 739         if (evlist->overwrite_mmap)
 740                 for (i = 0; i < evlist->core.nr_mmaps; i++)
 741                         perf_mmap__munmap(&evlist->overwrite_mmap[i].core);
 742 }
 743
 744 void evlist__munmap(struct evlist *evlist)
 745 {
 746         evlist__munmap_nofree(evlist);
 747         zfree(&evlist->mmap);
 748         zfree(&evlist->overwrite_mmap);
 749 }
 750
 751 static void perf_mmap__unmap_cb(struct perf_mmap *map)
 752 {
 753         struct mmap *m = container_of(map, struct mmap, core);
 754
 755         mmap__munmap(m);
 756 }
 757
 758 static struct mmap *evlist__alloc_mmap(struct evlist *evlist,
 759                                        bool overwrite)
 760 {
 761         int i;
 762         struct mmap *map;
 763
 764         map = zalloc(evlist->core.nr_mmaps * sizeof(struct mmap));
 765         if (!map)
 766                 return NULL;
 767
 768         for (i = 0; i < evlist->core.nr_mmaps; i++) {
 769                 struct perf_mmap *prev = i ? &map[i - 1].core : NULL;
 770
 771                 /*
 772                  * When the perf_mmap() call is made we grab one refcount, plus
 773                  * one extra to let perf_mmap__consume() get the last
 774                  * events after all real references (perf_mmap__get()) are
 775                  * dropped.
 776                  *
 777                  * Each PERF_EVENT_IOC_SET_OUTPUT points to this mmap and
 778                  * thus does perf_mmap__get() on it.
 779                  */
 780                 perf_mmap__init(&map[i].core, prev, overwrite, perf_mmap__unmap_cb);
 781         }
 782
 783         return map;
 784 }
 785
 786 static void
 787 perf_evlist__mmap_cb_idx(struct perf_evlist *_evlist,
 788                          struct perf_mmap_param *_mp,
 789                          int idx, bool per_cpu)
 790 {
 791         struct evlist *evlist = container_of(_evlist, struct evlist, core);
 792         struct mmap_params *mp = container_of(_mp, struct mmap_params, core);
 793
 794         auxtrace_mmap_params__set_idx(&mp->auxtrace_mp, evlist, idx, per_cpu);
 795 }
 796
 797 static struct perf_mmap*
 798 perf_evlist__mmap_cb_get(struct perf_evlist *_evlist, bool overwrite, int idx)
 799 {
 800         struct evlist *evlist = container_of(_evlist, struct evlist, core);
 801         struct mmap *maps;
 802
 803         maps = overwrite ? evlist->overwrite_mmap : evlist->mmap;
 804
 805         if (!maps) {
 806                 maps = evlist__alloc_mmap(evlist, overwrite);
 807                 if (!maps)
 808                         return NULL;
 809
 810                 if (overwrite) {
 811                         evlist->overwrite_mmap = maps;
 812                         if (evlist->bkw_mmap_state == BKW_MMAP_NOTREADY)
 813                                 evlist__toggle_bkw_mmap(evlist, BKW_MMAP_RUNNING);
 814                 } else {
 815                         evlist->mmap = maps;
 816                 }
 817         }
 818
 819         return &maps[idx].core;
 820 }
 821
 822 static int
 823 perf_evlist__mmap_cb_mmap(struct perf_mmap *_map, struct perf_mmap_param *_mp,
 824                           int output, int cpu)
 825 {
 826         struct mmap *map = container_of(_map, struct mmap, core);
 827         struct mmap_params *mp = container_of(_mp, struct mmap_params, core);
 828
 829         return mmap__mmap(map, mp, output, cpu);
 830 }
 831
 832 unsigned long perf_event_mlock_kb_in_pages(void)
 833 {
 834         unsigned long pages;
 835         int max;
 836
 837         if (sysctl__read_int("kernel/perf_event_mlock_kb", &max) < 0) {
 838                 /*
 839                  * Pick a once upon a time good value, i.e. things look
 840                  * strange since we can't read a sysctl value, but lets not
 841                  * die yet...
 842                  */
 843                 max = 512;
 844         } else {
 845                 max -= (page_size / 1024);
 846         }
 847
 848         pages = (max * 1024) / page_size;
 849         if (!is_power_of_2(pages))
 850                 pages = rounddown_pow_of_two(pages);
 851
 852         return pages;
 853 }
 854
 855 size_t evlist__mmap_size(unsigned long pages)
 856 {
 857         if (pages == UINT_MAX)
 858                 pages = perf_event_mlock_kb_in_pages();
 859         else if (!is_power_of_2(pages))
 860                 return 0;
 861
 862         return (pages + 1) * page_size;
 863 }
 864
 865 static long parse_pages_arg(const char *str, unsigned long min,
 866                             unsigned long max)
 867 {
 868         unsigned long pages, val;
 869         static struct parse_tag tags[] = {
 870                 { .tag  = 'B', .mult = 1       },
 871                 { .tag  = 'K', .mult = 1 << 10 },
 872                 { .tag  = 'M', .mult = 1 << 20 },
 873                 { .tag  = 'G', .mult = 1 << 30 },
 874                 { .tag  = 0 },
 875         };
 876
 877         if (str == NULL)
 878                 return -EINVAL;
 879
 880         val = parse_tag_value(str, tags);
 881         if (val != (unsigned long) -1) {
 882                 /* we got file size value */
 883                 pages = PERF_ALIGN(val, page_size) / page_size;
 884         } else {
 885                 /* we got pages count value */
 886                 char *eptr;
 887                 pages = strtoul(str, &eptr, 10);
 888                 if (*eptr != '\0')
 889                         return -EINVAL;
 890         }
 891
 892         if (pages == 0 && min == 0) {
 893                 /* leave number of pages at 0 */
 894         } else if (!is_power_of_2(pages)) {
 895                 char buf[100];
 896
 897                 /* round pages up to next power of 2 */
 898                 pages = roundup_pow_of_two(pages);
 899                 if (!pages)
 900                         return -EINVAL;
 901
 902                 unit_number__scnprintf(buf, sizeof(buf), pages * page_size);
 903                 pr_info("rounding mmap pages size to %s (%lu pages)\n",
 904                         buf, pages);
 905         }
 906
 907         if (pages > max)
 908                 return -EINVAL;
 909
 910         return pages;
 911 }
 912
 913 int __evlist__parse_mmap_pages(unsigned int *mmap_pages, const char *str)
 914 {
 915         unsigned long max = UINT_MAX;
 916         long pages;
 917
 918         if (max > SIZE_MAX / page_size)
 919                 max = SIZE_MAX / page_size;
 920
 921         pages = parse_pages_arg(str, 1, max);
 922         if (pages < 0) {
 923                 pr_err("Invalid argument for --mmap_pages/-m\n");
 924                 return -1;
 925         }
 926
 927         *mmap_pages = pages;
 928         return 0;
 929 }
 930
 931 int evlist__parse_mmap_pages(const struct option *opt, const char *str, int unset __maybe_unused)
 932 {
 933         return __evlist__parse_mmap_pages(opt->value, str);
 934 }
 935
 936 /**
 937  * evlist__mmap_ex - Create mmaps to receive events.
 938  * @evlist: list of events
 939  * @pages: map length in pages
 940  * @overwrite: overwrite older events?
 941  * @auxtrace_pages - auxtrace map length in pages
 942  * @auxtrace_overwrite - overwrite older auxtrace data?
 943  *
 944  * If @overwrite is %false the user needs to signal event consumption using
 945  * perf_mmap__write_tail().  Using evlist__mmap_read() does this
 946  * automatically.
 947  *
 948  * Similarly, if @auxtrace_overwrite is %false the user needs to signal data
 949  * consumption using auxtrace_mmap__write_tail().
 950  *
 951  * Return: %0 on success, negative error code otherwise.
 952  */
 953 int evlist__mmap_ex(struct evlist *evlist, unsigned int pages,
 954                          unsigned int auxtrace_pages,
 955                          bool auxtrace_overwrite, int nr_cblocks, int affinity, int flush,
 956                          int comp_level)
 957 {
 958         /*
 959          * Delay setting mp.prot: set it before calling perf_mmap__mmap.
 960          * Its value is decided by evsel's write_backward.
 961          * So &mp should not be passed through const pointer.
 962          */
 963         struct mmap_params mp = {
 964                 .nr_cblocks     = nr_cblocks,
 965                 .affinity       = affinity,
 966                 .flush          = flush,
 967                 .comp_level     = comp_level
 968         };
 969         struct perf_evlist_mmap_ops ops = {
 970                 .idx  = perf_evlist__mmap_cb_idx,
 971                 .get  = perf_evlist__mmap_cb_get,
 972                 .mmap = perf_evlist__mmap_cb_mmap,
 973         };
 974
 975         evlist->core.mmap_len = evlist__mmap_size(pages);
 976         pr_debug("mmap size %zuB\n", evlist->core.mmap_len);
 977
 978         auxtrace_mmap_params__init(&mp.auxtrace_mp, evlist->core.mmap_len,
 979                                    auxtrace_pages, auxtrace_overwrite);
 980
 981         return perf_evlist__mmap_ops(&evlist->core, &ops, &mp.core);
 982 }
 983
 984 int evlist__mmap(struct evlist *evlist, unsigned int pages)
 985 {
 986         return evlist__mmap_ex(evlist, pages, 0, false, 0, PERF_AFFINITY_SYS, 1, 0);
 987 }
 988
 989 int evlist__create_maps(struct evlist *evlist, struct target *target)
 990 {
 991         bool all_threads = (target->per_thread && target->system_wide);
 992         struct perf_cpu_map *cpus;
 993         struct perf_thread_map *threads;
 994
 995         /*
 996          * If specify '-a' and '--per-thread' to perf record, perf record
 997          * will override '--per-thread'. target->per_thread = false and
 998          * target->system_wide = true.
 999          *
1000          * If specify '--per-thread' only to perf record,
1001          * target->per_thread = true and target->system_wide = false.
1002          *
1003          * So target->per_thread && target->system_wide is false.
1004          * For perf record, thread_map__new_str doesn't call
1005          * thread_map__new_all_cpus. That will keep perf record's
1006          * current behavior.
1007          *
1008          * For perf stat, it allows the case that target->per_thread and
1009          * target->system_wide are all true. It means to collect system-wide
1010          * per-thread data. thread_map__new_str will call
1011          * thread_map__new_all_cpus to enumerate all threads.
1012          */
1013         threads = thread_map__new_str(target->pid, target->tid, target->uid,
1014                                       all_threads);
1015
1016         if (!threads)
1017                 return -1;
1018
1019         if (target__uses_dummy_map(target))
1020                 cpus = perf_cpu_map__dummy_new();
1021         else
1022                 cpus = perf_cpu_map__new(target->cpu_list);
1023
1024         if (!cpus)
1025                 goto out_delete_threads;
1026
1027         evlist->core.has_user_cpus = !!target->cpu_list;
1028
1029         perf_evlist__set_maps(&evlist->core, cpus, threads);
1030
1031         /* as evlist now has references, put count here */
1032         perf_cpu_map__put(cpus);
1033         perf_thread_map__put(threads);
1034
1035         return 0;
1036
1037 out_delete_threads:
1038         perf_thread_map__put(threads);
1039         return -1;
1040 }
1041
1042 int evlist__apply_filters(struct evlist *evlist, struct evsel **err_evsel)
1043 {
1044         struct evsel *evsel;
1045         int err = 0;
1046
1047         evlist__for_each_entry(evlist, evsel) {
1048                 if (evsel->filter == NULL)
1049                         continue;
1050
1051                 /*
1052                  * filters only work for tracepoint event, which doesn't have cpu limit.
1053                  * So evlist and evsel should always be same.
1054                  */
1055                 err = perf_evsel__apply_filter(&evsel->core, evsel->filter);
1056                 if (err) {
1057                         *err_evsel = evsel;
1058                         break;
1059                 }
1060         }
1061
1062         return err;
1063 }
1064
1065 int evlist__set_tp_filter(struct evlist *evlist, const char *filter)
1066 {
1067         struct evsel *evsel;
1068         int err = 0;
1069
1070         if (filter == NULL)
1071                 return -1;
1072
1073         evlist__for_each_entry(evlist, evsel) {
1074                 if (evsel->core.attr.type != PERF_TYPE_TRACEPOINT)
1075                         continue;
1076
1077                 err = evsel__set_filter(evsel, filter);
1078                 if (err)
1079                         break;
1080         }
1081
1082         return err;
1083 }
1084
1085 int evlist__append_tp_filter(struct evlist *evlist, const char *filter)
1086 {
1087         struct evsel *evsel;
1088         int err = 0;
1089
1090         if (filter == NULL)
1091                 return -1;
1092
1093         evlist__for_each_entry(evlist, evsel) {
1094                 if (evsel->core.attr.type != PERF_TYPE_TRACEPOINT)
1095                         continue;
1096
1097                 err = evsel__append_tp_filter(evsel, filter);
1098                 if (err)
1099                         break;
1100         }
1101
1102         return err;
1103 }
1104
1105 char *asprintf__tp_filter_pids(size_t npids, pid_t *pids)
1106 {
1107         char *filter;
1108         size_t i;
1109
1110         for (i = 0; i < npids; ++i) {
1111                 if (i == 0) {
1112                         if (asprintf(&filter, "common_pid != %d", pids[i]) < 0)
1113                                 return NULL;
1114                 } else {
1115                         char *tmp;
1116
1117                         if (asprintf(&tmp, "%s && common_pid != %d", filter, pids[i]) < 0)
1118                                 goto out_free;
1119
1120                         free(filter);
1121                         filter = tmp;
1122                 }
1123         }
1124
1125         return filter;
1126 out_free:
1127         free(filter);
1128         return NULL;
1129 }
1130
1131 int evlist__set_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *pids)
1132 {
1133         char *filter = asprintf__tp_filter_pids(npids, pids);
1134         int ret = evlist__set_tp_filter(evlist, filter);
1135
1136         free(filter);
1137         return ret;
1138 }
1139
1140 int evlist__set_tp_filter_pid(struct evlist *evlist, pid_t pid)
1141 {
1142         return evlist__set_tp_filter_pids(evlist, 1, &pid);
1143 }
1144
1145 int evlist__append_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *pids)
1146 {
1147         char *filter = asprintf__tp_filter_pids(npids, pids);
1148         int ret = evlist__append_tp_filter(evlist, filter);
1149
1150         free(filter);
1151         return ret;
1152 }
1153
1154 int evlist__append_tp_filter_pid(struct evlist *evlist, pid_t pid)
1155 {
1156         return evlist__append_tp_filter_pids(evlist, 1, &pid);
1157 }
1158
1159 bool evlist__valid_sample_type(struct evlist *evlist)
1160 {
1161         struct evsel *pos;
1162
1163         if (evlist->core.nr_entries == 1)
1164                 return true;
1165
1166         if (evlist->id_pos < 0 || evlist->is_pos < 0)
1167                 return false;
1168
1169         evlist__for_each_entry(evlist, pos) {
1170                 if (pos->id_pos != evlist->id_pos ||
1171                     pos->is_pos != evlist->is_pos)
1172                         return false;
1173         }
1174
1175         return true;
1176 }
1177
1178 u64 __evlist__combined_sample_type(struct evlist *evlist)
1179 {
1180         struct evsel *evsel;
1181
1182         if (evlist->combined_sample_type)
1183                 return evlist->combined_sample_type;
1184
1185         evlist__for_each_entry(evlist, evsel)
1186                 evlist->combined_sample_type |= evsel->core.attr.sample_type;
1187
1188         return evlist->combined_sample_type;
1189 }
1190
1191 u64 evlist__combined_sample_type(struct evlist *evlist)
1192 {
1193         evlist->combined_sample_type = 0;
1194         return __evlist__combined_sample_type(evlist);
1195 }
1196
1197 u64 evlist__combined_branch_type(struct evlist *evlist)
1198 {
1199         struct evsel *evsel;
1200         u64 branch_type = 0;
1201
1202         evlist__for_each_entry(evlist, evsel)
1203                 branch_type |= evsel->core.attr.branch_sample_type;
1204         return branch_type;
1205 }
1206
1207 bool evlist__valid_read_format(struct evlist *evlist)
1208 {
1209         struct evsel *first = evlist__first(evlist), *pos = first;
1210         u64 read_format = first->core.attr.read_format;
1211         u64 sample_type = first->core.attr.sample_type;
1212
1213         evlist__for_each_entry(evlist, pos) {
1214                 if (read_format != pos->core.attr.read_format) {
1215                         pr_debug("Read format differs %#" PRIx64 " vs %#" PRIx64 "\n",
1216                                  read_format, (u64)pos->core.attr.read_format);
1217                 }
1218         }
1219
1220         /* PERF_SAMPLE_READ implies PERF_FORMAT_ID. */
1221         if ((sample_type & PERF_SAMPLE_READ) &&
1222             !(read_format & PERF_FORMAT_ID)) {
1223                 return false;
1224         }
1225
1226         return true;
1227 }
1228
1229 u16 evlist__id_hdr_size(struct evlist *evlist)
1230 {
1231         struct evsel *first = evlist__first(evlist);
1232         struct perf_sample *data;
1233         u64 sample_type;
1234         u16 size = 0;
1235
1236         if (!first->core.attr.sample_id_all)
1237                 goto out;
1238
1239         sample_type = first->core.attr.sample_type;
1240
1241         if (sample_type & PERF_SAMPLE_TID)
1242                 size += sizeof(data->tid) * 2;
1243
1244        if (sample_type & PERF_SAMPLE_TIME)
1245                 size += sizeof(data->time);
1246
1247         if (sample_type & PERF_SAMPLE_ID)
1248                 size += sizeof(data->id);
1249
1250         if (sample_type & PERF_SAMPLE_STREAM_ID)
1251                 size += sizeof(data->stream_id);
1252
1253         if (sample_type & PERF_SAMPLE_CPU)
1254                 size += sizeof(data->cpu) * 2;
1255
1256         if (sample_type & PERF_SAMPLE_IDENTIFIER)
1257                 size += sizeof(data->id);
1258 out:
1259         return size;
1260 }
1261
1262 bool evlist__valid_sample_id_all(struct evlist *evlist)
1263 {
1264         struct evsel *first = evlist__first(evlist), *pos = first;
1265
1266         evlist__for_each_entry_continue(evlist, pos) {
1267                 if (first->core.attr.sample_id_all != pos->core.attr.sample_id_all)
1268                         return false;
1269         }
1270
1271         return true;
1272 }
1273
1274 bool evlist__sample_id_all(struct evlist *evlist)
1275 {
1276         struct evsel *first = evlist__first(evlist);
1277         return first->core.attr.sample_id_all;
1278 }
1279
1280 void evlist__set_selected(struct evlist *evlist, struct evsel *evsel)
1281 {
1282         evlist->selected = evsel;
1283 }
1284
1285 void evlist__close(struct evlist *evlist)
1286 {
1287         struct evsel *evsel;
1288         struct affinity affinity;
1289         int cpu, i;
1290
1291         /*
1292          * With perf record core.cpus is usually NULL.
1293          * Use the old method to handle this for now.
1294          */
1295         if (!evlist->core.cpus) {
1296                 evlist__for_each_entry_reverse(evlist, evsel)
1297                         evsel__close(evsel);
1298                 return;
1299         }
1300
1301         if (affinity__setup(&affinity) < 0)
1302                 return;
1303         evlist__for_each_cpu(evlist, i, cpu) {
1304                 affinity__set(&affinity, cpu);
1305
1306                 evlist__for_each_entry_reverse(evlist, evsel) {
1307                         if (evsel__cpu_iter_skip(evsel, cpu))
1308                             continue;
1309                         perf_evsel__close_cpu(&evsel->core, evsel->cpu_iter - 1);
1310                 }
1311         }
1312         affinity__cleanup(&affinity);
1313         evlist__for_each_entry_reverse(evlist, evsel) {
1314                 perf_evsel__free_fd(&evsel->core);
1315                 perf_evsel__free_id(&evsel->core);
1316         }
1317         perf_evlist__reset_id_hash(&evlist->core);
1318 }
1319
1320 static int evlist__create_syswide_maps(struct evlist *evlist)
1321 {
1322         struct perf_cpu_map *cpus;
1323         struct perf_thread_map *threads;
1324         int err = -ENOMEM;
1325
1326         /*
1327          * Try reading /sys/devices/system/cpu/online to get
1328          * an all cpus map.
1329          *
1330          * FIXME: -ENOMEM is the best we can do here, the cpu_map
1331          * code needs an overhaul to properly forward the
1332          * error, and we may not want to do that fallback to a
1333          * default cpu identity map :-\
1334          */
1335         cpus = perf_cpu_map__new(NULL);
1336         if (!cpus)
1337                 goto out;
1338
1339         threads = perf_thread_map__new_dummy();
1340         if (!threads)
1341                 goto out_put;
1342
1343         perf_evlist__set_maps(&evlist->core, cpus, threads);
1344
1345         perf_thread_map__put(threads);
1346 out_put:
1347         perf_cpu_map__put(cpus);
1348 out:
1349         return err;
1350 }
1351
1352 int evlist__open(struct evlist *evlist)
1353 {
1354         struct evsel *evsel;
1355         int err;
1356
1357         /*
1358          * Default: one fd per CPU, all threads, aka systemwide
1359          * as sys_perf_event_open(cpu = -1, thread = -1) is EINVAL
1360          */
1361         if (evlist->core.threads == NULL && evlist->core.cpus == NULL) {
1362                 err = evlist__create_syswide_maps(evlist);
1363                 if (err < 0)
1364                         goto out_err;
1365         }
1366
1367         evlist__update_id_pos(evlist);
1368
1369         evlist__for_each_entry(evlist, evsel) {
1370                 err = evsel__open(evsel, evsel->core.cpus, evsel->core.threads);
1371                 if (err < 0)
1372                         goto out_err;
1373         }
1374
1375         return 0;
1376 out_err:
1377         evlist__close(evlist);
1378         errno = -err;
1379         return err;
1380 }
1381
1382 int evlist__prepare_workload(struct evlist *evlist, struct target *target, const char *argv[],
1383                              bool pipe_output, void (*exec_error)(int signo, siginfo_t *info, void *ucontext))
1384 {
1385         int child_ready_pipe[2], go_pipe[2];
1386         char bf;
1387
1388         if (pipe(child_ready_pipe) < 0) {
1389                 perror("failed to create 'ready' pipe");
1390                 return -1;
1391         }
1392
1393         if (pipe(go_pipe) < 0) {
1394                 perror("failed to create 'go' pipe");
1395                 goto out_close_ready_pipe;
1396         }
1397
1398         evlist->workload.pid = fork();
1399         if (evlist->workload.pid < 0) {
1400                 perror("failed to fork");
1401                 goto out_close_pipes;
1402         }
1403
1404         if (!evlist->workload.pid) {
1405                 int ret;
1406
1407                 if (pipe_output)
1408                         dup2(2, 1);
1409
1410                 signal(SIGTERM, SIG_DFL);
1411
1412                 close(child_ready_pipe[0]);
1413                 close(go_pipe[1]);
1414                 fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
1415
1416                 /*
1417                  * Change the name of this process not to confuse --exclude-perf users
1418                  * that sees 'perf' in the window up to the execvp() and thinks that
1419                  * perf samples are not being excluded.
1420                  */
1421                 prctl(PR_SET_NAME, "perf-exec");
1422
1423                 /*
1424                  * Tell the parent we're ready to go
1425                  */
1426                 close(child_ready_pipe[1]);
1427
1428                 /*
1429                  * Wait until the parent tells us to go.
1430                  */
1431                 ret = read(go_pipe[0], &bf, 1);
1432                 /*
1433                  * The parent will ask for the execvp() to be performed by
1434                  * writing exactly one byte, in workload.cork_fd, usually via
1435                  * evlist__start_workload().
1436                  *
1437                  * For cancelling the workload without actually running it,
1438                  * the parent will just close workload.cork_fd, without writing
1439                  * anything, i.e. read will return zero and we just exit()
1440                  * here.
1441                  */
1442                 if (ret != 1) {
1443                         if (ret == -1)
1444                                 perror("unable to read pipe");
1445                         exit(ret);
1446                 }
1447
1448                 execvp(argv[0], (char **)argv);
1449
1450                 if (exec_error) {
1451                         union sigval val;
1452
1453                         val.sival_int = errno;
1454                         if (sigqueue(getppid(), SIGUSR1, val))
1455                                 perror(argv[0]);
1456                 } else
1457                         perror(argv[0]);
1458                 exit(-1);
1459         }
1460
1461         if (exec_error) {
1462                 struct sigaction act = {
1463                         .sa_flags     = SA_SIGINFO,
1464                         .sa_sigaction = exec_error,
1465                 };
1466                 sigaction(SIGUSR1, &act, NULL);
1467         }
1468
1469         if (target__none(target)) {
1470                 if (evlist->core.threads == NULL) {
1471                         fprintf(stderr, "FATAL: evlist->threads need to be set at this point (%s:%d).\n",
1472                                 __func__, __LINE__);
1473                         goto out_close_pipes;
1474                 }
1475                 perf_thread_map__set_pid(evlist->core.threads, 0, evlist->workload.pid);
1476         }
1477
1478         close(child_ready_pipe[1]);
1479         close(go_pipe[0]);
1480         /*
1481          * wait for child to settle
1482          */
1483         if (read(child_ready_pipe[0], &bf, 1) == -1) {
1484                 perror("unable to read pipe");
1485                 goto out_close_pipes;
1486         }
1487
1488         fcntl(go_pipe[1], F_SETFD, FD_CLOEXEC);
1489         evlist->workload.cork_fd = go_pipe[1];
1490         close(child_ready_pipe[0]);
1491         return 0;
1492
1493 out_close_pipes:
1494         close(go_pipe[0]);
1495         close(go_pipe[1]);
1496 out_close_ready_pipe:
1497         close(child_ready_pipe[0]);
1498         close(child_ready_pipe[1]);
1499         return -1;
1500 }
1501
1502 int evlist__start_workload(struct evlist *evlist)
1503 {
1504         if (evlist->workload.cork_fd > 0) {
1505                 char bf = 0;
1506                 int ret;
1507                 /*
1508                  * Remove the cork, let it rip!
1509                  */
1510                 ret = write(evlist->workload.cork_fd, &bf, 1);
1511                 if (ret < 0)
1512                         perror("unable to write to pipe");
1513
1514                 close(evlist->workload.cork_fd);
1515                 return ret;
1516         }
1517
1518         return 0;
1519 }
1520
1521 int evlist__parse_sample(struct evlist *evlist, union perf_event *event, struct perf_sample *sample)
1522 {
1523         struct evsel *evsel = evlist__event2evsel(evlist, event);
1524
1525         if (!evsel)
1526                 return -EFAULT;
1527         return evsel__parse_sample(evsel, event, sample);
1528 }
1529
1530 int evlist__parse_sample_timestamp(struct evlist *evlist, union perf_event *event, u64 *timestamp)
1531 {
1532         struct evsel *evsel = evlist__event2evsel(evlist, event);
1533
1534         if (!evsel)
1535                 return -EFAULT;
1536         return evsel__parse_sample_timestamp(evsel, event, timestamp);
1537 }
1538
1539 int evlist__strerror_open(struct evlist *evlist, int err, char *buf, size_t size)
1540 {
1541         int printed, value;
1542         char sbuf[STRERR_BUFSIZE], *emsg = str_error_r(err, sbuf, sizeof(sbuf));
1543
1544         switch (err) {
1545         case EACCES:
1546         case EPERM:
1547                 printed = scnprintf(buf, size,
1548                                     "Error:\t%s.\n"
1549                                     "Hint:\tCheck /proc/sys/kernel/perf_event_paranoid setting.", emsg);
1550
1551                 value = perf_event_paranoid();
1552
1553                 printed += scnprintf(buf + printed, size - printed, "\nHint:\t");
1554
1555                 if (value >= 2) {
1556                         printed += scnprintf(buf + printed, size - printed,
1557                                              "For your workloads it needs to be <= 1\nHint:\t");
1558                 }
1559                 printed += scnprintf(buf + printed, size - printed,
1560                                      "For system wide tracing it needs to be set to -1.\n");
1561
1562                 printed += scnprintf(buf + printed, size - printed,
1563                                     "Hint:\tTry: 'sudo sh -c \"echo -1 > /proc/sys/kernel/perf_event_paranoid\"'\n"
1564                                     "Hint:\tThe current value is %d.", value);
1565                 break;
1566         case EINVAL: {
1567                 struct evsel *first = evlist__first(evlist);
1568                 int max_freq;
1569
1570                 if (sysctl__read_int("kernel/perf_event_max_sample_rate", &max_freq) < 0)
1571                         goto out_default;
1572
1573                 if (first->core.attr.sample_freq < (u64)max_freq)
1574                         goto out_default;
1575
1576                 printed = scnprintf(buf, size,
1577                                     "Error:\t%s.\n"
1578                                     "Hint:\tCheck /proc/sys/kernel/perf_event_max_sample_rate.\n"
1579                                     "Hint:\tThe current value is %d and %" PRIu64 " is being requested.",
1580                                     emsg, max_freq, first->core.attr.sample_freq);
1581                 break;
1582         }
1583         default:
1584 out_default:
1585                 scnprintf(buf, size, "%s", emsg);
1586                 break;
1587         }
1588
1589         return 0;
1590 }
1591
1592 int evlist__strerror_mmap(struct evlist *evlist, int err, char *buf, size_t size)
1593 {
1594         char sbuf[STRERR_BUFSIZE], *emsg = str_error_r(err, sbuf, sizeof(sbuf));
1595         int pages_attempted = evlist->core.mmap_len / 1024, pages_max_per_user, printed = 0;
1596
1597         switch (err) {
1598         case EPERM:
1599                 sysctl__read_int("kernel/perf_event_mlock_kb", &pages_max_per_user);
1600                 printed += scnprintf(buf + printed, size - printed,
1601                                      "Error:\t%s.\n"
1602                                      "Hint:\tCheck /proc/sys/kernel/perf_event_mlock_kb (%d kB) setting.\n"
1603                                      "Hint:\tTried using %zd kB.\n",
1604                                      emsg, pages_max_per_user, pages_attempted);
1605
1606                 if (pages_attempted >= pages_max_per_user) {
1607                         printed += scnprintf(buf + printed, size - printed,
1608                                              "Hint:\tTry 'sudo sh -c \"echo %d > /proc/sys/kernel/perf_event_mlock_kb\"', or\n",
1609                                              pages_max_per_user + pages_attempted);
1610                 }
1611
1612                 printed += scnprintf(buf + printed, size - printed,
1613                                      "Hint:\tTry using a smaller -m/--mmap-pages value.");
1614                 break;
1615         default:
1616                 scnprintf(buf, size, "%s", emsg);
1617                 break;
1618         }
1619
1620         return 0;
1621 }
1622
1623 void evlist__to_front(struct evlist *evlist, struct evsel *move_evsel)
1624 {
1625         struct evsel *evsel, *n;
1626         LIST_HEAD(move);
1627
1628         if (move_evsel == evlist__first(evlist))
1629                 return;
1630
1631         evlist__for_each_entry_safe(evlist, n, evsel) {
1632                 if (evsel->leader == move_evsel->leader)
1633                         list_move_tail(&evsel->core.node, &move);
1634         }
1635
1636         list_splice(&move, &evlist->core.entries);
1637 }
1638
1639 struct evsel *evlist__get_tracking_event(struct evlist *evlist)
1640 {
1641         struct evsel *evsel;
1642
1643         evlist__for_each_entry(evlist, evsel) {
1644                 if (evsel->tracking)
1645                         return evsel;
1646         }
1647
1648         return evlist__first(evlist);
1649 }
1650
1651 void evlist__set_tracking_event(struct evlist *evlist, struct evsel *tracking_evsel)
1652 {
1653         struct evsel *evsel;
1654
1655         if (tracking_evsel->tracking)
1656                 return;
1657
1658         evlist__for_each_entry(evlist, evsel) {
1659                 if (evsel != tracking_evsel)
1660                         evsel->tracking = false;
1661         }
1662
1663         tracking_evsel->tracking = true;
1664 }
1665
1666 struct evsel *evlist__find_evsel_by_str(struct evlist *evlist, const char *str)
1667 {
1668         struct evsel *evsel;
1669
1670         evlist__for_each_entry(evlist, evsel) {
1671                 if (!evsel->name)
1672                         continue;
1673                 if (strcmp(str, evsel->name) == 0)
1674                         return evsel;
1675         }
1676
1677         return NULL;
1678 }
1679
1680 void evlist__toggle_bkw_mmap(struct evlist *evlist, enum bkw_mmap_state state)
1681 {
1682         enum bkw_mmap_state old_state = evlist->bkw_mmap_state;
1683         enum action {
1684                 NONE,
1685                 PAUSE,
1686                 RESUME,
1687         } action = NONE;
1688
1689         if (!evlist->overwrite_mmap)
1690                 return;
1691
1692         switch (old_state) {
1693         case BKW_MMAP_NOTREADY: {
1694                 if (state != BKW_MMAP_RUNNING)
1695                         goto state_err;
1696                 break;
1697         }
1698         case BKW_MMAP_RUNNING: {
1699                 if (state != BKW_MMAP_DATA_PENDING)
1700                         goto state_err;
1701                 action = PAUSE;
1702                 break;
1703         }
1704         case BKW_MMAP_DATA_PENDING: {
1705                 if (state != BKW_MMAP_EMPTY)
1706                         goto state_err;
1707                 break;
1708         }
1709         case BKW_MMAP_EMPTY: {
1710                 if (state != BKW_MMAP_RUNNING)
1711                         goto state_err;
1712                 action = RESUME;
1713                 break;
1714         }
1715         default:
1716                 WARN_ONCE(1, "Shouldn't get there\n");
1717         }
1718
1719         evlist->bkw_mmap_state = state;
1720
1721         switch (action) {
1722         case PAUSE:
1723                 evlist__pause(evlist);
1724                 break;
1725         case RESUME:
1726                 evlist__resume(evlist);
1727                 break;
1728         case NONE:
1729         default:
1730                 break;
1731         }
1732
1733 state_err:
1734         return;
1735 }
1736
1737 bool evlist__exclude_kernel(struct evlist *evlist)
1738 {
1739         struct evsel *evsel;
1740
1741         evlist__for_each_entry(evlist, evsel) {
1742                 if (!evsel->core.attr.exclude_kernel)
1743                         return false;
1744         }
1745
1746         return true;
1747 }
1748
1749 /*
1750  * Events in data file are not collect in groups, but we still want
1751  * the group display. Set the artificial group and set the leader's
1752  * forced_leader flag to notify the display code.
1753  */
1754 void evlist__force_leader(struct evlist *evlist)
1755 {
1756         if (!evlist->nr_groups) {
1757                 struct evsel *leader = evlist__first(evlist);
1758
1759                 evlist__set_leader(evlist);
1760                 leader->forced_leader = true;
1761         }
1762 }
1763
1764 struct evsel *evlist__reset_weak_group(struct evlist *evsel_list, struct evsel *evsel, bool close)
1765 {
1766         struct evsel *c2, *leader;
1767         bool is_open = true;
1768
1769         leader = evsel->leader;
1770         pr_debug("Weak group for %s/%d failed\n",
1771                         leader->name, leader->core.nr_members);
1772
1773         /*
1774          * for_each_group_member doesn't work here because it doesn't
1775          * include the first entry.
1776          */
1777         evlist__for_each_entry(evsel_list, c2) {
1778                 if (c2 == evsel)
1779                         is_open = false;
1780                 if (c2->leader == leader) {
1781                         if (is_open && close)
1782                                 perf_evsel__close(&c2->core);
1783                         c2->leader = c2;
1784                         c2->core.nr_members = 0;
1785                         /*
1786                          * Set this for all former members of the group
1787                          * to indicate they get reopened.
1788                          */
1789                         c2->reset_group = true;
1790                 }
1791         }
1792         return leader;
1793 }
1794
1795 static int evlist__parse_control_fifo(const char *str, int *ctl_fd, int *ctl_fd_ack, bool *ctl_fd_close)
1796 {
1797         char *s, *p;
1798         int ret = 0, fd;
1799
1800         if (strncmp(str, "fifo:", 5))
1801                 return -EINVAL;
1802
1803         str += 5;
1804         if (!*str || *str == ',')
1805                 return -EINVAL;
1806
1807         s = strdup(str);
1808         if (!s)
1809                 return -ENOMEM;
1810
1811         p = strchr(s, ',');
1812         if (p)
1813                 *p = '\0';
1814
1815         /*
1816          * O_RDWR avoids POLLHUPs which is necessary to allow the other
1817          * end of a FIFO to be repeatedly opened and closed.
1818          */
1819         fd = open(s, O_RDWR | O_NONBLOCK | O_CLOEXEC);
1820         if (fd < 0) {
1821                 pr_err("Failed to open '%s'\n", s);
1822                 ret = -errno;
1823                 goto out_free;
1824         }
1825         *ctl_fd = fd;
1826         *ctl_fd_close = true;
1827
1828         if (p && *++p) {
1829                 /* O_RDWR | O_NONBLOCK means the other end need not be open */
1830                 fd = open(p, O_RDWR | O_NONBLOCK | O_CLOEXEC);
1831                 if (fd < 0) {
1832                         pr_err("Failed to open '%s'\n", p);
1833                         ret = -errno;
1834                         goto out_free;
1835                 }
1836                 *ctl_fd_ack = fd;
1837         }
1838
1839 out_free:
1840         free(s);
1841         return ret;
1842 }
1843
1844 int evlist__parse_control(const char *str, int *ctl_fd, int *ctl_fd_ack, bool *ctl_fd_close)
1845 {
1846         char *comma = NULL, *endptr = NULL;
1847
1848         *ctl_fd_close = false;
1849
1850         if (strncmp(str, "fd:", 3))
1851                 return evlist__parse_control_fifo(str, ctl_fd, ctl_fd_ack, ctl_fd_close);
1852
1853         *ctl_fd = strtoul(&str[3], &endptr, 0);
1854         if (endptr == &str[3])
1855                 return -EINVAL;
1856
1857         comma = strchr(str, ',');
1858         if (comma) {
1859                 if (endptr != comma)
1860                         return -EINVAL;
1861
1862                 *ctl_fd_ack = strtoul(comma + 1, &endptr, 0);
1863                 if (endptr == comma + 1 || *endptr != '\0')
1864                         return -EINVAL;
1865         }
1866
1867         return 0;
1868 }
1869
1870 void evlist__close_control(int ctl_fd, int ctl_fd_ack, bool *ctl_fd_close)
1871 {
1872         if (*ctl_fd_close) {
1873                 *ctl_fd_close = false;
1874                 close(ctl_fd);
1875                 if (ctl_fd_ack >= 0)
1876                         close(ctl_fd_ack);
1877         }
1878 }
1879
1880 int evlist__initialize_ctlfd(struct evlist *evlist, int fd, int ack)
1881 {
1882         if (fd == -1) {
1883                 pr_debug("Control descriptor is not initialized\n");
1884                 return 0;
1885         }
1886
1887         evlist->ctl_fd.pos = perf_evlist__add_pollfd(&evlist->core, fd, NULL, POLLIN,
1888                                                      fdarray_flag__nonfilterable);
1889         if (evlist->ctl_fd.pos < 0) {
1890                 evlist->ctl_fd.pos = -1;
1891                 pr_err("Failed to add ctl fd entry: %m\n");
1892                 return -1;
1893         }
1894
1895         evlist->ctl_fd.fd = fd;
1896         evlist->ctl_fd.ack = ack;
1897
1898         return 0;
1899 }
1900
1901 bool evlist__ctlfd_initialized(struct evlist *evlist)
1902 {
1903         return evlist->ctl_fd.pos >= 0;
1904 }
1905
1906 int evlist__finalize_ctlfd(struct evlist *evlist)
1907 {
1908         struct pollfd *entries = evlist->core.pollfd.entries;
1909
1910         if (!evlist__ctlfd_initialized(evlist))
1911                 return 0;
1912
1913         entries[evlist->ctl_fd.pos].fd = -1;
1914         entries[evlist->ctl_fd.pos].events = 0;
1915         entries[evlist->ctl_fd.pos].revents = 0;
1916
1917         evlist->ctl_fd.pos = -1;
1918         evlist->ctl_fd.ack = -1;
1919         evlist->ctl_fd.fd = -1;
1920
1921         return 0;
1922 }
1923
1924 static int evlist__ctlfd_recv(struct evlist *evlist, enum evlist_ctl_cmd *cmd,
1925                               char *cmd_data, size_t data_size)
1926 {
1927         int err;
1928         char c;
1929         size_t bytes_read = 0;
1930
1931         *cmd = EVLIST_CTL_CMD_UNSUPPORTED;
1932         memset(cmd_data, 0, data_size);
1933         data_size--;
1934
1935         do {
1936                 err = read(evlist->ctl_fd.fd, &c, 1);
1937                 if (err > 0) {
1938                         if (c == '\n' || c == '\0')
1939                                 break;
1940                         cmd_data[bytes_read++] = c;
1941                         if (bytes_read == data_size)
1942                                 break;
1943                         continue;
1944                 } else if (err == -1) {
1945                         if (errno == EINTR)
1946                                 continue;
1947                         if (errno == EAGAIN || errno == EWOULDBLOCK)
1948                                 err = 0;
1949                         else
1950                                 pr_err("Failed to read from ctlfd %d: %m\n", evlist->ctl_fd.fd);
1951                 }
1952                 break;
1953         } while (1);
1954
1955         pr_debug("Message from ctl_fd: \"%s%s\"\n", cmd_data,
1956                  bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0");
1957
1958         if (bytes_read > 0) {
1959                 if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG,
1960                              (sizeof(EVLIST_CTL_CMD_ENABLE_TAG)-1))) {
1961                         *cmd = EVLIST_CTL_CMD_ENABLE;
1962                 } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG,
1963                                     (sizeof(EVLIST_CTL_CMD_DISABLE_TAG)-1))) {
1964                         *cmd = EVLIST_CTL_CMD_DISABLE;
1965                 } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_SNAPSHOT_TAG,
1966                                     (sizeof(EVLIST_CTL_CMD_SNAPSHOT_TAG)-1))) {
1967                         *cmd = EVLIST_CTL_CMD_SNAPSHOT;
1968                         pr_debug("is snapshot\n");
1969                 } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_EVLIST_TAG,
1970                                     (sizeof(EVLIST_CTL_CMD_EVLIST_TAG)-1))) {
1971                         *cmd = EVLIST_CTL_CMD_EVLIST;
1972                 } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_STOP_TAG,
1973                                     (sizeof(EVLIST_CTL_CMD_STOP_TAG)-1))) {
1974                         *cmd = EVLIST_CTL_CMD_STOP;
1975                 } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_PING_TAG,
1976                                     (sizeof(EVLIST_CTL_CMD_PING_TAG)-1))) {
1977                         *cmd = EVLIST_CTL_CMD_PING;
1978                 }
1979         }
1980
1981         return bytes_read ? (int)bytes_read : err;
1982 }
1983
1984 int evlist__ctlfd_ack(struct evlist *evlist)
1985 {
1986         int err;
1987
1988         if (evlist->ctl_fd.ack == -1)
1989                 return 0;
1990
1991         err = write(evlist->ctl_fd.ack, EVLIST_CTL_CMD_ACK_TAG,
1992                     sizeof(EVLIST_CTL_CMD_ACK_TAG));
1993         if (err == -1)
1994                 pr_err("failed to write to ctl_ack_fd %d: %m\n", evlist->ctl_fd.ack);
1995
1996         return err;
1997 }
1998
1999 static int get_cmd_arg(char *cmd_data, size_t cmd_size, char **arg)
2000 {
2001         char *data = cmd_data + cmd_size;
2002
2003         /* no argument */
2004         if (!*data)
2005                 return 0;
2006
2007         /* there's argument */
2008         if (*data == ' ') {
2009                 *arg = data + 1;
2010                 return 1;
2011         }
2012
2013         /* malformed */
2014         return -1;
2015 }
2016
2017 static int evlist__ctlfd_enable(struct evlist *evlist, char *cmd_data, bool enable)
2018 {
2019         struct evsel *evsel;
2020         char *name;
2021         int err;
2022
2023         err = get_cmd_arg(cmd_data,
2024                           enable ? sizeof(EVLIST_CTL_CMD_ENABLE_TAG) - 1 :
2025                                    sizeof(EVLIST_CTL_CMD_DISABLE_TAG) - 1,
2026                           &name);
2027         if (err < 0) {
2028                 pr_info("failed: wrong command\n");
2029                 return -1;
2030         }
2031
2032         if (err) {
2033                 evsel = evlist__find_evsel_by_str(evlist, name);
2034                 if (evsel) {
2035                         if (enable)
2036                                 evlist__enable_evsel(evlist, name);
2037                         else
2038                                 evlist__disable_evsel(evlist, name);
2039                         pr_info("Event %s %s\n", evsel->name,
2040                                 enable ? "enabled" : "disabled");
2041                 } else {
2042                         pr_info("failed: can't find '%s' event\n", name);
2043                 }
2044         } else {
2045                 if (enable) {
2046                         evlist__enable(evlist);
2047                         pr_info(EVLIST_ENABLED_MSG);
2048                 } else {
2049                         evlist__disable(evlist);
2050                         pr_info(EVLIST_DISABLED_MSG);
2051                 }
2052         }
2053
2054         return 0;
2055 }
2056
2057 static int evlist__ctlfd_list(struct evlist *evlist, char *cmd_data)
2058 {
2059         struct perf_attr_details details = { .verbose = false, };
2060         struct evsel *evsel;
2061         char *arg;
2062         int err;
2063
2064         err = get_cmd_arg(cmd_data,
2065                           sizeof(EVLIST_CTL_CMD_EVLIST_TAG) - 1,
2066                           &arg);
2067         if (err < 0) {
2068                 pr_info("failed: wrong command\n");
2069                 return -1;
2070         }
2071
2072         if (err) {
2073                 if (!strcmp(arg, "-v")) {
2074                         details.verbose = true;
2075                 } else if (!strcmp(arg, "-g")) {
2076                         details.event_group = true;
2077                 } else if (!strcmp(arg, "-F")) {
2078                         details.freq = true;
2079                 } else {
2080                         pr_info("failed: wrong command\n");
2081                         return -1;
2082                 }
2083         }
2084
2085         evlist__for_each_entry(evlist, evsel)
2086                 evsel__fprintf(evsel, &details, stderr);
2087
2088         return 0;
2089 }
2090
2091 int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd)
2092 {
2093         int err = 0;
2094         char cmd_data[EVLIST_CTL_CMD_MAX_LEN];
2095         int ctlfd_pos = evlist->ctl_fd.pos;
2096         struct pollfd *entries = evlist->core.pollfd.entries;
2097
2098         if (!evlist__ctlfd_initialized(evlist) || !entries[ctlfd_pos].revents)
2099                 return 0;
2100
2101         if (entries[ctlfd_pos].revents & POLLIN) {
2102                 err = evlist__ctlfd_recv(evlist, cmd, cmd_data,
2103                                          EVLIST_CTL_CMD_MAX_LEN);
2104                 if (err > 0) {
2105                         switch (*cmd) {
2106                         case EVLIST_CTL_CMD_ENABLE:
2107                         case EVLIST_CTL_CMD_DISABLE:
2108                                 err = evlist__ctlfd_enable(evlist, cmd_data,
2109                                                            *cmd == EVLIST_CTL_CMD_ENABLE);
2110                                 break;
2111                         case EVLIST_CTL_CMD_EVLIST:
2112                                 err = evlist__ctlfd_list(evlist, cmd_data);
2113                                 break;
2114                         case EVLIST_CTL_CMD_SNAPSHOT:
2115                         case EVLIST_CTL_CMD_STOP:
2116                         case EVLIST_CTL_CMD_PING:
2117                                 break;
2118                         case EVLIST_CTL_CMD_ACK:
2119                         case EVLIST_CTL_CMD_UNSUPPORTED:
2120                         default:
2121                                 pr_debug("ctlfd: unsupported %d\n", *cmd);
2122                                 break;
2123                         }
2124                         if (!(*cmd == EVLIST_CTL_CMD_ACK || *cmd == EVLIST_CTL_CMD_UNSUPPORTED ||
2125                               *cmd == EVLIST_CTL_CMD_SNAPSHOT))
2126                                 evlist__ctlfd_ack(evlist);
2127                 }
2128         }
2129
2130         if (entries[ctlfd_pos].revents & (POLLHUP | POLLERR))
2131                 evlist__finalize_ctlfd(evlist);
2132         else
2133                 entries[ctlfd_pos].revents = 0;
2134
2135         return err;
2136 }
2137
2138 struct evsel *evlist__find_evsel(struct evlist *evlist, int idx)
2139 {
2140         struct evsel *evsel;
2141
2142         evlist__for_each_entry(evlist, evsel) {
2143                 if (evsel->idx == idx)
2144                         return evsel;
2145         }
2146         return NULL;
2147 }
2148
2149 int evlist__scnprintf_evsels(struct evlist *evlist, size_t size, char *bf)
2150 {
2151         struct evsel *evsel;
2152         int printed = 0;
2153
2154         evlist__for_each_entry(evlist, evsel) {
2155                 if (evsel__is_dummy_event(evsel))
2156                         continue;
2157                 if (size > (strlen(evsel__name(evsel)) + (printed ? 2 : 1))) {
2158                         printed += scnprintf(bf + printed, size - printed, "%s%s", printed ? "," : "", evsel__name(evsel));
2159                 } else {
2160                         printed += scnprintf(bf + printed, size - printed, "%s...", printed ? "," : "");
2161                         break;
2162                 }
2163         }
2164
2165         return printed;
2166 }