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 "util/pmu.h"
  31 #include <signal.h>
  32 #include <unistd.h>
  33 #include <sched.h>
  34 #include <stdlib.h>
  35
  36 #include "parse-events.h"
  37 #include <subcmd/parse-options.h>
  38
  39 #include <fcntl.h>
  40 #include <sys/ioctl.h>
  41 #include <sys/mman.h>
  42 #include <sys/prctl.h>
  43
  44 #include <linux/bitops.h>
  45 #include <linux/hash.h>
  46 #include <linux/log2.h>
  47 #include <linux/err.h>
  48 #include <linux/string.h>
  49 #include <linux/zalloc.h>
  50 #include <perf/evlist.h>
  51 #include <perf/evsel.h>
  52 #include <perf/cpumap.h>
  53 #include <perf/mmap.h>
  54
  55 #include <internal/xyarray.h>
  56
  57 #ifdef LACKS_SIGQUEUE_PROTOTYPE
  58 int sigqueue(pid_t pid, int sig, const union sigval value);
  59 #endif
  60
  61 #define FD(e, x, y) (*(int *)xyarray__entry(e->core.fd, x, y))
  62 #define SID(e, x, y) xyarray__entry(e->core.sample_id, x, y)
  63
  64 void evlist__init(struct evlist *evlist, struct perf_cpu_map *cpus,
  65                   struct perf_thread_map *threads)
  66 {
  67         perf_evlist__init(&evlist->core);
  68         perf_evlist__set_maps(&evlist->core, cpus, threads);
  69         evlist->workload.pid = -1;
  70         evlist->bkw_mmap_state = BKW_MMAP_NOTREADY;
  71         evlist->ctl_fd.fd = -1;
  72         evlist->ctl_fd.ack = -1;
  73         evlist->ctl_fd.pos = -1;
  74 }
  75
  76 struct evlist *evlist__new(void)
  77 {
  78         struct evlist *evlist = zalloc(sizeof(*evlist));
  79
  80         if (evlist != NULL)
  81                 evlist__init(evlist, NULL, NULL);
  82
  83         return evlist;
  84 }
  85
  86 struct evlist *evlist__new_default(void)
  87 {
  88         struct evlist *evlist = evlist__new();
  89
  90         if (evlist && evlist__add_default(evlist)) {
  91                 evlist__delete(evlist);
  92                 evlist = NULL;
  93         }
  94
  95         return evlist;
  96 }
  97
  98 struct evlist *evlist__new_dummy(void)
  99 {
 100         struct evlist *evlist = evlist__new();
 101
 102         if (evlist && evlist__add_dummy(evlist)) {
 103                 evlist__delete(evlist);
 104                 evlist = NULL;
 105         }
 106
 107         return evlist;
 108 }
 109
 110 /**
 111  * evlist__set_id_pos - set the positions of event ids.
 112  * @evlist: selected event list
 113  *
 114  * Events with compatible sample types all have the same id_pos
 115  * and is_pos.  For convenience, put a copy on evlist.
 116  */
 117 void evlist__set_id_pos(struct evlist *evlist)
 118 {
 119         struct evsel *first = evlist__first(evlist);
 120
 121         evlist->id_pos = first->id_pos;
 122         evlist->is_pos = first->is_pos;
 123 }
 124
 125 static void evlist__update_id_pos(struct evlist *evlist)
 126 {
 127         struct evsel *evsel;
 128
 129         evlist__for_each_entry(evlist, evsel)
 130                 evsel__calc_id_pos(evsel);
 131
 132         evlist__set_id_pos(evlist);
 133 }
 134
 135 static void evlist__purge(struct evlist *evlist)
 136 {
 137         struct evsel *pos, *n;
 138
 139         evlist__for_each_entry_safe(evlist, n, pos) {
 140                 list_del_init(&pos->core.node);
 141                 pos->evlist = NULL;
 142                 evsel__delete(pos);
 143         }
 144
 145         evlist->core.nr_entries = 0;
 146 }
 147
 148 void evlist__exit(struct evlist *evlist)
 149 {
 150         zfree(&evlist->mmap);
 151         zfree(&evlist->overwrite_mmap);
 152         perf_evlist__exit(&evlist->core);
 153 }
 154
 155 void evlist__delete(struct evlist *evlist)
 156 {
 157         if (evlist == NULL)
 158                 return;
 159
 160         evlist__munmap(evlist);
 161         evlist__close(evlist);
 162         evlist__purge(evlist);
 163         evlist__exit(evlist);
 164         free(evlist);
 165 }
 166
 167 void evlist__add(struct evlist *evlist, struct evsel *entry)
 168 {
 169         perf_evlist__add(&evlist->core, &entry->core);
 170         entry->evlist = evlist;
 171         entry->tracking = !entry->core.idx;
 172
 173         if (evlist->core.nr_entries == 1)
 174                 evlist__set_id_pos(evlist);
 175 }
 176
 177 void evlist__remove(struct evlist *evlist, struct evsel *evsel)
 178 {
 179         evsel->evlist = NULL;
 180         perf_evlist__remove(&evlist->core, &evsel->core);
 181 }
 182
 183 void evlist__splice_list_tail(struct evlist *evlist, struct list_head *list)
 184 {
 185         while (!list_empty(list)) {
 186                 struct evsel *evsel, *temp, *leader = NULL;
 187
 188                 __evlist__for_each_entry_safe(list, temp, evsel) {
 189                         list_del_init(&evsel->core.node);
 190                         evlist__add(evlist, evsel);
 191                         leader = evsel;
 192                         break;
 193                 }
 194
 195                 __evlist__for_each_entry_safe(list, temp, evsel) {
 196                         if (evsel__has_leader(evsel, leader)) {
 197                                 list_del_init(&evsel->core.node);
 198                                 evlist__add(evlist, evsel);
 199                         }
 200                 }
 201         }
 202 }
 203
 204 int __evlist__set_tracepoints_handlers(struct evlist *evlist,
 205                                        const struct evsel_str_handler *assocs, size_t nr_assocs)
 206 {
 207         size_t i;
 208         int err;
 209
 210         for (i = 0; i < nr_assocs; i++) {
 211                 // Adding a handler for an event not in this evlist, just ignore it.
 212                 struct evsel *evsel = evlist__find_tracepoint_by_name(evlist, assocs[i].name);
 213                 if (evsel == NULL)
 214                         continue;
 215
 216                 err = -EEXIST;
 217                 if (evsel->handler != NULL)
 218                         goto out;
 219                 evsel->handler = assocs[i].handler;
 220         }
 221
 222         err = 0;
 223 out:
 224         return err;
 225 }
 226
 227 void evlist__set_leader(struct evlist *evlist)
 228 {
 229         perf_evlist__set_leader(&evlist->core);
 230 }
 231
 232 int __evlist__add_default(struct evlist *evlist, bool precise)
 233 {
 234         struct evsel *evsel;
 235
 236         evsel = evsel__new_cycles(precise, PERF_TYPE_HARDWARE,
 237                                   PERF_COUNT_HW_CPU_CYCLES);
 238         if (evsel == NULL)
 239                 return -ENOMEM;
 240
 241         evlist__add(evlist, evsel);
 242         return 0;
 243 }
 244
 245 int evlist__add_dummy(struct evlist *evlist)
 246 {
 247         struct perf_event_attr attr = {
 248                 .type   = PERF_TYPE_SOFTWARE,
 249                 .config = PERF_COUNT_SW_DUMMY,
 250                 .size   = sizeof(attr), /* to capture ABI version */
 251         };
 252         struct evsel *evsel = evsel__new_idx(&attr, evlist->core.nr_entries);
 253
 254         if (evsel == NULL)
 255                 return -ENOMEM;
 256
 257         evlist__add(evlist, evsel);
 258         return 0;
 259 }
 260
 261 static int evlist__add_attrs(struct evlist *evlist, struct perf_event_attr *attrs, size_t nr_attrs)
 262 {
 263         struct evsel *evsel, *n;
 264         LIST_HEAD(head);
 265         size_t i;
 266
 267         for (i = 0; i < nr_attrs; i++) {
 268                 evsel = evsel__new_idx(attrs + i, evlist->core.nr_entries + i);
 269                 if (evsel == NULL)
 270                         goto out_delete_partial_list;
 271                 list_add_tail(&evsel->core.node, &head);
 272         }
 273
 274         evlist__splice_list_tail(evlist, &head);
 275
 276         return 0;
 277
 278 out_delete_partial_list:
 279         __evlist__for_each_entry_safe(&head, n, evsel)
 280                 evsel__delete(evsel);
 281         return -1;
 282 }
 283
 284 int __evlist__add_default_attrs(struct evlist *evlist, struct perf_event_attr *attrs, size_t nr_attrs)
 285 {
 286         size_t i;
 287
 288         for (i = 0; i < nr_attrs; i++)
 289                 event_attr_init(attrs + i);
 290
 291         return evlist__add_attrs(evlist, attrs, nr_attrs);
 292 }
 293
 294 __weak int arch_evlist__add_default_attrs(struct evlist *evlist __maybe_unused)
 295 {
 296         return 0;
 297 }
 298
 299 struct evsel *evlist__find_tracepoint_by_id(struct evlist *evlist, int id)
 300 {
 301         struct evsel *evsel;
 302
 303         evlist__for_each_entry(evlist, evsel) {
 304                 if (evsel->core.attr.type   == PERF_TYPE_TRACEPOINT &&
 305                     (int)evsel->core.attr.config == id)
 306                         return evsel;
 307         }
 308
 309         return NULL;
 310 }
 311
 312 struct evsel *evlist__find_tracepoint_by_name(struct evlist *evlist, const char *name)
 313 {
 314         struct evsel *evsel;
 315
 316         evlist__for_each_entry(evlist, evsel) {
 317                 if ((evsel->core.attr.type == PERF_TYPE_TRACEPOINT) &&
 318                     (strcmp(evsel->name, name) == 0))
 319                         return evsel;
 320         }
 321
 322         return NULL;
 323 }
 324
 325 int evlist__add_newtp(struct evlist *evlist, const char *sys, const char *name, void *handler)
 326 {
 327         struct evsel *evsel = evsel__newtp(sys, name);
 328
 329         if (IS_ERR(evsel))
 330                 return -1;
 331
 332         evsel->handler = handler;
 333         evlist__add(evlist, evsel);
 334         return 0;
 335 }
 336
 337 static int evlist__nr_threads(struct evlist *evlist, struct evsel *evsel)
 338 {
 339         if (evsel->core.system_wide)
 340                 return 1;
 341         else
 342                 return perf_thread_map__nr(evlist->core.threads);
 343 }
 344
 345 struct evlist_cpu_iterator evlist__cpu_begin(struct evlist *evlist, struct affinity *affinity)
 346 {
 347         struct evlist_cpu_iterator itr = {
 348                 .container = evlist,
 349                 .evsel = NULL,
 350                 .cpu_map_idx = 0,
 351                 .evlist_cpu_map_idx = 0,
 352                 .evlist_cpu_map_nr = perf_cpu_map__nr(evlist->core.all_cpus),
 353                 .cpu = (struct perf_cpu){ .cpu = -1},
 354                 .affinity = affinity,
 355         };
 356
 357         if (evlist__empty(evlist)) {
 358                 /* Ensure the empty list doesn't iterate. */
 359                 itr.evlist_cpu_map_idx = itr.evlist_cpu_map_nr;
 360         } else {
 361                 itr.evsel = evlist__first(evlist);
 362                 if (itr.affinity) {
 363                         itr.cpu = perf_cpu_map__cpu(evlist->core.all_cpus, 0);
 364                         affinity__set(itr.affinity, itr.cpu.cpu);
 365                         itr.cpu_map_idx = perf_cpu_map__idx(itr.evsel->core.cpus, itr.cpu);
 366                         /*
 367                          * If this CPU isn't in the evsel's cpu map then advance
 368                          * through the list.
 369                          */
 370                         if (itr.cpu_map_idx == -1)
 371                                 evlist_cpu_iterator__next(&itr);
 372                 }
 373         }
 374         return itr;
 375 }
 376
 377 void evlist_cpu_iterator__next(struct evlist_cpu_iterator *evlist_cpu_itr)
 378 {
 379         while (evlist_cpu_itr->evsel != evlist__last(evlist_cpu_itr->container)) {
 380                 evlist_cpu_itr->evsel = evsel__next(evlist_cpu_itr->evsel);
 381                 evlist_cpu_itr->cpu_map_idx =
 382                         perf_cpu_map__idx(evlist_cpu_itr->evsel->core.cpus,
 383                                           evlist_cpu_itr->cpu);
 384                 if (evlist_cpu_itr->cpu_map_idx != -1)
 385                         return;
 386         }
 387         evlist_cpu_itr->evlist_cpu_map_idx++;
 388         if (evlist_cpu_itr->evlist_cpu_map_idx < evlist_cpu_itr->evlist_cpu_map_nr) {
 389                 evlist_cpu_itr->evsel = evlist__first(evlist_cpu_itr->container);
 390                 evlist_cpu_itr->cpu =
 391                         perf_cpu_map__cpu(evlist_cpu_itr->container->core.all_cpus,
 392                                           evlist_cpu_itr->evlist_cpu_map_idx);
 393                 if (evlist_cpu_itr->affinity)
 394                         affinity__set(evlist_cpu_itr->affinity, evlist_cpu_itr->cpu.cpu);
 395                 evlist_cpu_itr->cpu_map_idx =
 396                         perf_cpu_map__idx(evlist_cpu_itr->evsel->core.cpus,
 397                                           evlist_cpu_itr->cpu);
 398                 /*
 399                  * If this CPU isn't in the evsel's cpu map then advance through
 400                  * the list.
 401                  */
 402                 if (evlist_cpu_itr->cpu_map_idx == -1)
 403                         evlist_cpu_iterator__next(evlist_cpu_itr);
 404         }
 405 }
 406
 407 bool evlist_cpu_iterator__end(const struct evlist_cpu_iterator *evlist_cpu_itr)
 408 {
 409         return evlist_cpu_itr->evlist_cpu_map_idx >= evlist_cpu_itr->evlist_cpu_map_nr;
 410 }
 411
 412 static int evsel__strcmp(struct evsel *pos, char *evsel_name)
 413 {
 414         if (!evsel_name)
 415                 return 0;
 416         if (evsel__is_dummy_event(pos))
 417                 return 1;
 418         return strcmp(pos->name, evsel_name);
 419 }
 420
 421 static int evlist__is_enabled(struct evlist *evlist)
 422 {
 423         struct evsel *pos;
 424
 425         evlist__for_each_entry(evlist, pos) {
 426                 if (!evsel__is_group_leader(pos) || !pos->core.fd)
 427                         continue;
 428                 /* If at least one event is enabled, evlist is enabled. */
 429                 if (!pos->disabled)
 430                         return true;
 431         }
 432         return false;
 433 }
 434
 435 static void __evlist__disable(struct evlist *evlist, char *evsel_name)
 436 {
 437         struct evsel *pos;
 438         struct evlist_cpu_iterator evlist_cpu_itr;
 439         struct affinity saved_affinity, *affinity = NULL;
 440         bool has_imm = false;
 441
 442         // See explanation in evlist__close()
 443         if (!cpu_map__is_dummy(evlist->core.cpus)) {
 444                 if (affinity__setup(&saved_affinity) < 0)
 445                         return;
 446                 affinity = &saved_affinity;
 447         }
 448
 449         /* Disable 'immediate' events last */
 450         for (int imm = 0; imm <= 1; imm++) {
 451                 evlist__for_each_cpu(evlist_cpu_itr, evlist, affinity) {
 452                         pos = evlist_cpu_itr.evsel;
 453                         if (evsel__strcmp(pos, evsel_name))
 454                                 continue;
 455                         if (pos->disabled || !evsel__is_group_leader(pos) || !pos->core.fd)
 456                                 continue;
 457                         if (pos->immediate)
 458                                 has_imm = true;
 459                         if (pos->immediate != imm)
 460                                 continue;
 461                         evsel__disable_cpu(pos, evlist_cpu_itr.cpu_map_idx);
 462                 }
 463                 if (!has_imm)
 464                         break;
 465         }
 466
 467         affinity__cleanup(affinity);
 468         evlist__for_each_entry(evlist, pos) {
 469                 if (evsel__strcmp(pos, evsel_name))
 470                         continue;
 471                 if (!evsel__is_group_leader(pos) || !pos->core.fd)
 472                         continue;
 473                 pos->disabled = true;
 474         }
 475
 476         /*
 477          * If we disabled only single event, we need to check
 478          * the enabled state of the evlist manually.
 479          */
 480         if (evsel_name)
 481                 evlist->enabled = evlist__is_enabled(evlist);
 482         else
 483                 evlist->enabled = false;
 484 }
 485
 486 void evlist__disable(struct evlist *evlist)
 487 {
 488         __evlist__disable(evlist, NULL);
 489 }
 490
 491 void evlist__disable_evsel(struct evlist *evlist, char *evsel_name)
 492 {
 493         __evlist__disable(evlist, evsel_name);
 494 }
 495
 496 static void __evlist__enable(struct evlist *evlist, char *evsel_name)
 497 {
 498         struct evsel *pos;
 499         struct evlist_cpu_iterator evlist_cpu_itr;
 500         struct affinity saved_affinity, *affinity = NULL;
 501
 502         // See explanation in evlist__close()
 503         if (!cpu_map__is_dummy(evlist->core.cpus)) {
 504                 if (affinity__setup(&saved_affinity) < 0)
 505                         return;
 506                 affinity = &saved_affinity;
 507         }
 508
 509         evlist__for_each_cpu(evlist_cpu_itr, evlist, affinity) {
 510                 pos = evlist_cpu_itr.evsel;
 511                 if (evsel__strcmp(pos, evsel_name))
 512                         continue;
 513                 if (!evsel__is_group_leader(pos) || !pos->core.fd)
 514                         continue;
 515                 evsel__enable_cpu(pos, evlist_cpu_itr.cpu_map_idx);
 516         }
 517         affinity__cleanup(affinity);
 518         evlist__for_each_entry(evlist, pos) {
 519                 if (evsel__strcmp(pos, evsel_name))
 520                         continue;
 521                 if (!evsel__is_group_leader(pos) || !pos->core.fd)
 522                         continue;
 523                 pos->disabled = false;
 524         }
 525
 526         /*
 527          * Even single event sets the 'enabled' for evlist,
 528          * so the toggle can work properly and toggle to
 529          * 'disabled' state.
 530          */
 531         evlist->enabled = true;
 532 }
 533
 534 void evlist__enable(struct evlist *evlist)
 535 {
 536         __evlist__enable(evlist, NULL);
 537 }
 538
 539 void evlist__enable_evsel(struct evlist *evlist, char *evsel_name)
 540 {
 541         __evlist__enable(evlist, evsel_name);
 542 }
 543
 544 void evlist__toggle_enable(struct evlist *evlist)
 545 {
 546         (evlist->enabled ? evlist__disable : evlist__enable)(evlist);
 547 }
 548
 549 static int evlist__enable_event_cpu(struct evlist *evlist, struct evsel *evsel, int cpu)
 550 {
 551         int thread;
 552         int nr_threads = evlist__nr_threads(evlist, evsel);
 553
 554         if (!evsel->core.fd)
 555                 return -EINVAL;
 556
 557         for (thread = 0; thread < nr_threads; thread++) {
 558                 int err = ioctl(FD(evsel, cpu, thread), PERF_EVENT_IOC_ENABLE, 0);
 559                 if (err)
 560                         return err;
 561         }
 562         return 0;
 563 }
 564
 565 static int evlist__enable_event_thread(struct evlist *evlist, struct evsel *evsel, int thread)
 566 {
 567         int cpu;
 568         int nr_cpus = perf_cpu_map__nr(evlist->core.cpus);
 569
 570         if (!evsel->core.fd)
 571                 return -EINVAL;
 572
 573         for (cpu = 0; cpu < nr_cpus; cpu++) {
 574                 int err = ioctl(FD(evsel, cpu, thread), PERF_EVENT_IOC_ENABLE, 0);
 575                 if (err)
 576                         return err;
 577         }
 578         return 0;
 579 }
 580
 581 int evlist__enable_event_idx(struct evlist *evlist, struct evsel *evsel, int idx)
 582 {
 583         bool per_cpu_mmaps = !perf_cpu_map__empty(evlist->core.cpus);
 584
 585         if (per_cpu_mmaps)
 586                 return evlist__enable_event_cpu(evlist, evsel, idx);
 587
 588         return evlist__enable_event_thread(evlist, evsel, idx);
 589 }
 590
 591 int evlist__add_pollfd(struct evlist *evlist, int fd)
 592 {
 593         return perf_evlist__add_pollfd(&evlist->core, fd, NULL, POLLIN, fdarray_flag__default);
 594 }
 595
 596 int evlist__filter_pollfd(struct evlist *evlist, short revents_and_mask)
 597 {
 598         return perf_evlist__filter_pollfd(&evlist->core, revents_and_mask);
 599 }
 600
 601 #ifdef HAVE_EVENTFD_SUPPORT
 602 int evlist__add_wakeup_eventfd(struct evlist *evlist, int fd)
 603 {
 604         return perf_evlist__add_pollfd(&evlist->core, fd, NULL, POLLIN,
 605                                        fdarray_flag__nonfilterable);
 606 }
 607 #endif
 608
 609 int evlist__poll(struct evlist *evlist, int timeout)
 610 {
 611         return perf_evlist__poll(&evlist->core, timeout);
 612 }
 613
 614 struct perf_sample_id *evlist__id2sid(struct evlist *evlist, u64 id)
 615 {
 616         struct hlist_head *head;
 617         struct perf_sample_id *sid;
 618         int hash;
 619
 620         hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
 621         head = &evlist->core.heads[hash];
 622
 623         hlist_for_each_entry(sid, head, node)
 624                 if (sid->id == id)
 625                         return sid;
 626
 627         return NULL;
 628 }
 629
 630 struct evsel *evlist__id2evsel(struct evlist *evlist, u64 id)
 631 {
 632         struct perf_sample_id *sid;
 633
 634         if (evlist->core.nr_entries == 1 || !id)
 635                 return evlist__first(evlist);
 636
 637         sid = evlist__id2sid(evlist, id);
 638         if (sid)
 639                 return container_of(sid->evsel, struct evsel, core);
 640
 641         if (!evlist__sample_id_all(evlist))
 642                 return evlist__first(evlist);
 643
 644         return NULL;
 645 }
 646
 647 struct evsel *evlist__id2evsel_strict(struct evlist *evlist, u64 id)
 648 {
 649         struct perf_sample_id *sid;
 650
 651         if (!id)
 652                 return NULL;
 653
 654         sid = evlist__id2sid(evlist, id);
 655         if (sid)
 656                 return container_of(sid->evsel, struct evsel, core);
 657
 658         return NULL;
 659 }
 660
 661 static int evlist__event2id(struct evlist *evlist, union perf_event *event, u64 *id)
 662 {
 663         const __u64 *array = event->sample.array;
 664         ssize_t n;
 665
 666         n = (event->header.size - sizeof(event->header)) >> 3;
 667
 668         if (event->header.type == PERF_RECORD_SAMPLE) {
 669                 if (evlist->id_pos >= n)
 670                         return -1;
 671                 *id = array[evlist->id_pos];
 672         } else {
 673                 if (evlist->is_pos > n)
 674                         return -1;
 675                 n -= evlist->is_pos;
 676                 *id = array[n];
 677         }
 678         return 0;
 679 }
 680
 681 struct evsel *evlist__event2evsel(struct evlist *evlist, union perf_event *event)
 682 {
 683         struct evsel *first = evlist__first(evlist);
 684         struct hlist_head *head;
 685         struct perf_sample_id *sid;
 686         int hash;
 687         u64 id;
 688
 689         if (evlist->core.nr_entries == 1)
 690                 return first;
 691
 692         if (!first->core.attr.sample_id_all &&
 693             event->header.type != PERF_RECORD_SAMPLE)
 694                 return first;
 695
 696         if (evlist__event2id(evlist, event, &id))
 697                 return NULL;
 698
 699         /* Synthesized events have an id of zero */
 700         if (!id)
 701                 return first;
 702
 703         hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
 704         head = &evlist->core.heads[hash];
 705
 706         hlist_for_each_entry(sid, head, node) {
 707                 if (sid->id == id)
 708                         return container_of(sid->evsel, struct evsel, core);
 709         }
 710         return NULL;
 711 }
 712
 713 static int evlist__set_paused(struct evlist *evlist, bool value)
 714 {
 715         int i;
 716
 717         if (!evlist->overwrite_mmap)
 718                 return 0;
 719
 720         for (i = 0; i < evlist->core.nr_mmaps; i++) {
 721                 int fd = evlist->overwrite_mmap[i].core.fd;
 722                 int err;
 723
 724                 if (fd < 0)
 725                         continue;
 726                 err = ioctl(fd, PERF_EVENT_IOC_PAUSE_OUTPUT, value ? 1 : 0);
 727                 if (err)
 728                         return err;
 729         }
 730         return 0;
 731 }
 732
 733 static int evlist__pause(struct evlist *evlist)
 734 {
 735         return evlist__set_paused(evlist, true);
 736 }
 737
 738 static int evlist__resume(struct evlist *evlist)
 739 {
 740         return evlist__set_paused(evlist, false);
 741 }
 742
 743 static void evlist__munmap_nofree(struct evlist *evlist)
 744 {
 745         int i;
 746
 747         if (evlist->mmap)
 748                 for (i = 0; i < evlist->core.nr_mmaps; i++)
 749                         perf_mmap__munmap(&evlist->mmap[i].core);
 750
 751         if (evlist->overwrite_mmap)
 752                 for (i = 0; i < evlist->core.nr_mmaps; i++)
 753                         perf_mmap__munmap(&evlist->overwrite_mmap[i].core);
 754 }
 755
 756 void evlist__munmap(struct evlist *evlist)
 757 {
 758         evlist__munmap_nofree(evlist);
 759         zfree(&evlist->mmap);
 760         zfree(&evlist->overwrite_mmap);
 761 }
 762
 763 static void perf_mmap__unmap_cb(struct perf_mmap *map)
 764 {
 765         struct mmap *m = container_of(map, struct mmap, core);
 766
 767         mmap__munmap(m);
 768 }
 769
 770 static struct mmap *evlist__alloc_mmap(struct evlist *evlist,
 771                                        bool overwrite)
 772 {
 773         int i;
 774         struct mmap *map;
 775
 776         map = zalloc(evlist->core.nr_mmaps * sizeof(struct mmap));
 777         if (!map)
 778                 return NULL;
 779
 780         for (i = 0; i < evlist->core.nr_mmaps; i++) {
 781                 struct perf_mmap *prev = i ? &map[i - 1].core : NULL;
 782
 783                 /*
 784                  * When the perf_mmap() call is made we grab one refcount, plus
 785                  * one extra to let perf_mmap__consume() get the last
 786                  * events after all real references (perf_mmap__get()) are
 787                  * dropped.
 788                  *
 789                  * Each PERF_EVENT_IOC_SET_OUTPUT points to this mmap and
 790                  * thus does perf_mmap__get() on it.
 791                  */
 792                 perf_mmap__init(&map[i].core, prev, overwrite, perf_mmap__unmap_cb);
 793         }
 794
 795         return map;
 796 }
 797
 798 static void
 799 perf_evlist__mmap_cb_idx(struct perf_evlist *_evlist,
 800                          struct perf_mmap_param *_mp,
 801                          int idx, bool per_cpu)
 802 {
 803         struct evlist *evlist = container_of(_evlist, struct evlist, core);
 804         struct mmap_params *mp = container_of(_mp, struct mmap_params, core);
 805
 806         auxtrace_mmap_params__set_idx(&mp->auxtrace_mp, evlist, idx, per_cpu);
 807 }
 808
 809 static struct perf_mmap*
 810 perf_evlist__mmap_cb_get(struct perf_evlist *_evlist, bool overwrite, int idx)
 811 {
 812         struct evlist *evlist = container_of(_evlist, struct evlist, core);
 813         struct mmap *maps;
 814
 815         maps = overwrite ? evlist->overwrite_mmap : evlist->mmap;
 816
 817         if (!maps) {
 818                 maps = evlist__alloc_mmap(evlist, overwrite);
 819                 if (!maps)
 820                         return NULL;
 821
 822                 if (overwrite) {
 823                         evlist->overwrite_mmap = maps;
 824                         if (evlist->bkw_mmap_state == BKW_MMAP_NOTREADY)
 825                                 evlist__toggle_bkw_mmap(evlist, BKW_MMAP_RUNNING);
 826                 } else {
 827                         evlist->mmap = maps;
 828                 }
 829         }
 830
 831         return &maps[idx].core;
 832 }
 833
 834 static int
 835 perf_evlist__mmap_cb_mmap(struct perf_mmap *_map, struct perf_mmap_param *_mp,
 836                           int output, struct perf_cpu cpu)
 837 {
 838         struct mmap *map = container_of(_map, struct mmap, core);
 839         struct mmap_params *mp = container_of(_mp, struct mmap_params, core);
 840
 841         return mmap__mmap(map, mp, output, cpu);
 842 }
 843
 844 unsigned long perf_event_mlock_kb_in_pages(void)
 845 {
 846         unsigned long pages;
 847         int max;
 848
 849         if (sysctl__read_int("kernel/perf_event_mlock_kb", &max) < 0) {
 850                 /*
 851                  * Pick a once upon a time good value, i.e. things look
 852                  * strange since we can't read a sysctl value, but lets not
 853                  * die yet...
 854                  */
 855                 max = 512;
 856         } else {
 857                 max -= (page_size / 1024);
 858         }
 859
 860         pages = (max * 1024) / page_size;
 861         if (!is_power_of_2(pages))
 862                 pages = rounddown_pow_of_two(pages);
 863
 864         return pages;
 865 }
 866
 867 size_t evlist__mmap_size(unsigned long pages)
 868 {
 869         if (pages == UINT_MAX)
 870                 pages = perf_event_mlock_kb_in_pages();
 871         else if (!is_power_of_2(pages))
 872                 return 0;
 873
 874         return (pages + 1) * page_size;
 875 }
 876
 877 static long parse_pages_arg(const char *str, unsigned long min,
 878                             unsigned long max)
 879 {
 880         unsigned long pages, val;
 881         static struct parse_tag tags[] = {
 882                 { .tag  = 'B', .mult = 1       },
 883                 { .tag  = 'K', .mult = 1 << 10 },
 884                 { .tag  = 'M', .mult = 1 << 20 },
 885                 { .tag  = 'G', .mult = 1 << 30 },
 886                 { .tag  = 0 },
 887         };
 888
 889         if (str == NULL)
 890                 return -EINVAL;
 891
 892         val = parse_tag_value(str, tags);
 893         if (val != (unsigned long) -1) {
 894                 /* we got file size value */
 895                 pages = PERF_ALIGN(val, page_size) / page_size;
 896         } else {
 897                 /* we got pages count value */
 898                 char *eptr;
 899                 pages = strtoul(str, &eptr, 10);
 900                 if (*eptr != '\0')
 901                         return -EINVAL;
 902         }
 903
 904         if (pages == 0 && min == 0) {
 905                 /* leave number of pages at 0 */
 906         } else if (!is_power_of_2(pages)) {
 907                 char buf[100];
 908
 909                 /* round pages up to next power of 2 */
 910                 pages = roundup_pow_of_two(pages);
 911                 if (!pages)
 912                         return -EINVAL;
 913
 914                 unit_number__scnprintf(buf, sizeof(buf), pages * page_size);
 915                 pr_info("rounding mmap pages size to %s (%lu pages)\n",
 916                         buf, pages);
 917         }
 918
 919         if (pages > max)
 920                 return -EINVAL;
 921
 922         return pages;
 923 }
 924
 925 int __evlist__parse_mmap_pages(unsigned int *mmap_pages, const char *str)
 926 {
 927         unsigned long max = UINT_MAX;
 928         long pages;
 929
 930         if (max > SIZE_MAX / page_size)
 931                 max = SIZE_MAX / page_size;
 932
 933         pages = parse_pages_arg(str, 1, max);
 934         if (pages < 0) {
 935                 pr_err("Invalid argument for --mmap_pages/-m\n");
 936                 return -1;
 937         }
 938
 939         *mmap_pages = pages;
 940         return 0;
 941 }
 942
 943 int evlist__parse_mmap_pages(const struct option *opt, const char *str, int unset __maybe_unused)
 944 {
 945         return __evlist__parse_mmap_pages(opt->value, str);
 946 }
 947
 948 /**
 949  * evlist__mmap_ex - Create mmaps to receive events.
 950  * @evlist: list of events
 951  * @pages: map length in pages
 952  * @overwrite: overwrite older events?
 953  * @auxtrace_pages - auxtrace map length in pages
 954  * @auxtrace_overwrite - overwrite older auxtrace data?
 955  *
 956  * If @overwrite is %false the user needs to signal event consumption using
 957  * perf_mmap__write_tail().  Using evlist__mmap_read() does this
 958  * automatically.
 959  *
 960  * Similarly, if @auxtrace_overwrite is %false the user needs to signal data
 961  * consumption using auxtrace_mmap__write_tail().
 962  *
 963  * Return: %0 on success, negative error code otherwise.
 964  */
 965 int evlist__mmap_ex(struct evlist *evlist, unsigned int pages,
 966                          unsigned int auxtrace_pages,
 967                          bool auxtrace_overwrite, int nr_cblocks, int affinity, int flush,
 968                          int comp_level)
 969 {
 970         /*
 971          * Delay setting mp.prot: set it before calling perf_mmap__mmap.
 972          * Its value is decided by evsel's write_backward.
 973          * So &mp should not be passed through const pointer.
 974          */
 975         struct mmap_params mp = {
 976                 .nr_cblocks     = nr_cblocks,
 977                 .affinity       = affinity,
 978                 .flush          = flush,
 979                 .comp_level     = comp_level
 980         };
 981         struct perf_evlist_mmap_ops ops = {
 982                 .idx  = perf_evlist__mmap_cb_idx,
 983                 .get  = perf_evlist__mmap_cb_get,
 984                 .mmap = perf_evlist__mmap_cb_mmap,
 985         };
 986
 987         evlist->core.mmap_len = evlist__mmap_size(pages);
 988         pr_debug("mmap size %zuB\n", evlist->core.mmap_len);
 989
 990         auxtrace_mmap_params__init(&mp.auxtrace_mp, evlist->core.mmap_len,
 991                                    auxtrace_pages, auxtrace_overwrite);
 992
 993         return perf_evlist__mmap_ops(&evlist->core, &ops, &mp.core);
 994 }
 995
 996 int evlist__mmap(struct evlist *evlist, unsigned int pages)
 997 {
 998         return evlist__mmap_ex(evlist, pages, 0, false, 0, PERF_AFFINITY_SYS, 1, 0);
 999 }
1000
1001 int evlist__create_maps(struct evlist *evlist, struct target *target)
1002 {
1003         bool all_threads = (target->per_thread && target->system_wide);
1004         struct perf_cpu_map *cpus;
1005         struct perf_thread_map *threads;
1006
1007         /*
1008          * If specify '-a' and '--per-thread' to perf record, perf record
1009          * will override '--per-thread'. target->per_thread = false and
1010          * target->system_wide = true.
1011          *
1012          * If specify '--per-thread' only to perf record,
1013          * target->per_thread = true and target->system_wide = false.
1014          *
1015          * So target->per_thread && target->system_wide is false.
1016          * For perf record, thread_map__new_str doesn't call
1017          * thread_map__new_all_cpus. That will keep perf record's
1018          * current behavior.
1019          *
1020          * For perf stat, it allows the case that target->per_thread and
1021          * target->system_wide are all true. It means to collect system-wide
1022          * per-thread data. thread_map__new_str will call
1023          * thread_map__new_all_cpus to enumerate all threads.
1024          */
1025         threads = thread_map__new_str(target->pid, target->tid, target->uid,
1026                                       all_threads);
1027
1028         if (!threads)
1029                 return -1;
1030
1031         if (target__uses_dummy_map(target))
1032                 cpus = perf_cpu_map__dummy_new();
1033         else
1034                 cpus = perf_cpu_map__new(target->cpu_list);
1035
1036         if (!cpus)
1037                 goto out_delete_threads;
1038
1039         evlist->core.has_user_cpus = !!target->cpu_list && !target->hybrid;
1040
1041         perf_evlist__set_maps(&evlist->core, cpus, threads);
1042
1043         /* as evlist now has references, put count here */
1044         perf_cpu_map__put(cpus);
1045         perf_thread_map__put(threads);
1046
1047         return 0;
1048
1049 out_delete_threads:
1050         perf_thread_map__put(threads);
1051         return -1;
1052 }
1053
1054 int evlist__apply_filters(struct evlist *evlist, struct evsel **err_evsel)
1055 {
1056         struct evsel *evsel;
1057         int err = 0;
1058
1059         evlist__for_each_entry(evlist, evsel) {
1060                 if (evsel->filter == NULL)
1061                         continue;
1062
1063                 /*
1064                  * filters only work for tracepoint event, which doesn't have cpu limit.
1065                  * So evlist and evsel should always be same.
1066                  */
1067                 err = perf_evsel__apply_filter(&evsel->core, evsel->filter);
1068                 if (err) {
1069                         *err_evsel = evsel;
1070                         break;
1071                 }
1072         }
1073
1074         return err;
1075 }
1076
1077 int evlist__set_tp_filter(struct evlist *evlist, const char *filter)
1078 {
1079         struct evsel *evsel;
1080         int err = 0;
1081
1082         if (filter == NULL)
1083                 return -1;
1084
1085         evlist__for_each_entry(evlist, evsel) {
1086                 if (evsel->core.attr.type != PERF_TYPE_TRACEPOINT)
1087                         continue;
1088
1089                 err = evsel__set_filter(evsel, filter);
1090                 if (err)
1091                         break;
1092         }
1093
1094         return err;
1095 }
1096
1097 int evlist__append_tp_filter(struct evlist *evlist, const char *filter)
1098 {
1099         struct evsel *evsel;
1100         int err = 0;
1101
1102         if (filter == NULL)
1103                 return -1;
1104
1105         evlist__for_each_entry(evlist, evsel) {
1106                 if (evsel->core.attr.type != PERF_TYPE_TRACEPOINT)
1107                         continue;
1108
1109                 err = evsel__append_tp_filter(evsel, filter);
1110                 if (err)
1111                         break;
1112         }
1113
1114         return err;
1115 }
1116
1117 char *asprintf__tp_filter_pids(size_t npids, pid_t *pids)
1118 {
1119         char *filter;
1120         size_t i;
1121
1122         for (i = 0; i < npids; ++i) {
1123                 if (i == 0) {
1124                         if (asprintf(&filter, "common_pid != %d", pids[i]) < 0)
1125                                 return NULL;
1126                 } else {
1127                         char *tmp;
1128
1129                         if (asprintf(&tmp, "%s && common_pid != %d", filter, pids[i]) < 0)
1130                                 goto out_free;
1131
1132                         free(filter);
1133                         filter = tmp;
1134                 }
1135         }
1136
1137         return filter;
1138 out_free:
1139         free(filter);
1140         return NULL;
1141 }
1142
1143 int evlist__set_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *pids)
1144 {
1145         char *filter = asprintf__tp_filter_pids(npids, pids);
1146         int ret = evlist__set_tp_filter(evlist, filter);
1147
1148         free(filter);
1149         return ret;
1150 }
1151
1152 int evlist__set_tp_filter_pid(struct evlist *evlist, pid_t pid)
1153 {
1154         return evlist__set_tp_filter_pids(evlist, 1, &pid);
1155 }
1156
1157 int evlist__append_tp_filter_pids(struct evlist *evlist, size_t npids, pid_t *pids)
1158 {
1159         char *filter = asprintf__tp_filter_pids(npids, pids);
1160         int ret = evlist__append_tp_filter(evlist, filter);
1161
1162         free(filter);
1163         return ret;
1164 }
1165
1166 int evlist__append_tp_filter_pid(struct evlist *evlist, pid_t pid)
1167 {
1168         return evlist__append_tp_filter_pids(evlist, 1, &pid);
1169 }
1170
1171 bool evlist__valid_sample_type(struct evlist *evlist)
1172 {
1173         struct evsel *pos;
1174
1175         if (evlist->core.nr_entries == 1)
1176                 return true;
1177
1178         if (evlist->id_pos < 0 || evlist->is_pos < 0)
1179                 return false;
1180
1181         evlist__for_each_entry(evlist, pos) {
1182                 if (pos->id_pos != evlist->id_pos ||
1183                     pos->is_pos != evlist->is_pos)
1184                         return false;
1185         }
1186
1187         return true;
1188 }
1189
1190 u64 __evlist__combined_sample_type(struct evlist *evlist)
1191 {
1192         struct evsel *evsel;
1193
1194         if (evlist->combined_sample_type)
1195                 return evlist->combined_sample_type;
1196
1197         evlist__for_each_entry(evlist, evsel)
1198                 evlist->combined_sample_type |= evsel->core.attr.sample_type;
1199
1200         return evlist->combined_sample_type;
1201 }
1202
1203 u64 evlist__combined_sample_type(struct evlist *evlist)
1204 {
1205         evlist->combined_sample_type = 0;
1206         return __evlist__combined_sample_type(evlist);
1207 }
1208
1209 u64 evlist__combined_branch_type(struct evlist *evlist)
1210 {
1211         struct evsel *evsel;
1212         u64 branch_type = 0;
1213
1214         evlist__for_each_entry(evlist, evsel)
1215                 branch_type |= evsel->core.attr.branch_sample_type;
1216         return branch_type;
1217 }
1218
1219 bool evlist__valid_read_format(struct evlist *evlist)
1220 {
1221         struct evsel *first = evlist__first(evlist), *pos = first;
1222         u64 read_format = first->core.attr.read_format;
1223         u64 sample_type = first->core.attr.sample_type;
1224
1225         evlist__for_each_entry(evlist, pos) {
1226                 if (read_format != pos->core.attr.read_format) {
1227                         pr_debug("Read format differs %#" PRIx64 " vs %#" PRIx64 "\n",
1228                                  read_format, (u64)pos->core.attr.read_format);
1229                 }
1230         }
1231
1232         /* PERF_SAMPLE_READ implies PERF_FORMAT_ID. */
1233         if ((sample_type & PERF_SAMPLE_READ) &&
1234             !(read_format & PERF_FORMAT_ID)) {
1235                 return false;
1236         }
1237
1238         return true;
1239 }
1240
1241 u16 evlist__id_hdr_size(struct evlist *evlist)
1242 {
1243         struct evsel *first = evlist__first(evlist);
1244         struct perf_sample *data;
1245         u64 sample_type;
1246         u16 size = 0;
1247
1248         if (!first->core.attr.sample_id_all)
1249                 goto out;
1250
1251         sample_type = first->core.attr.sample_type;
1252
1253         if (sample_type & PERF_SAMPLE_TID)
1254                 size += sizeof(data->tid) * 2;
1255
1256        if (sample_type & PERF_SAMPLE_TIME)
1257                 size += sizeof(data->time);
1258
1259         if (sample_type & PERF_SAMPLE_ID)
1260                 size += sizeof(data->id);
1261
1262         if (sample_type & PERF_SAMPLE_STREAM_ID)
1263                 size += sizeof(data->stream_id);
1264
1265         if (sample_type & PERF_SAMPLE_CPU)
1266                 size += sizeof(data->cpu) * 2;
1267
1268         if (sample_type & PERF_SAMPLE_IDENTIFIER)
1269                 size += sizeof(data->id);
1270 out:
1271         return size;
1272 }
1273
1274 bool evlist__valid_sample_id_all(struct evlist *evlist)
1275 {
1276         struct evsel *first = evlist__first(evlist), *pos = first;
1277
1278         evlist__for_each_entry_continue(evlist, pos) {
1279                 if (first->core.attr.sample_id_all != pos->core.attr.sample_id_all)
1280                         return false;
1281         }
1282
1283         return true;
1284 }
1285
1286 bool evlist__sample_id_all(struct evlist *evlist)
1287 {
1288         struct evsel *first = evlist__first(evlist);
1289         return first->core.attr.sample_id_all;
1290 }
1291
1292 void evlist__set_selected(struct evlist *evlist, struct evsel *evsel)
1293 {
1294         evlist->selected = evsel;
1295 }
1296
1297 void evlist__close(struct evlist *evlist)
1298 {
1299         struct evsel *evsel;
1300         struct evlist_cpu_iterator evlist_cpu_itr;
1301         struct affinity affinity;
1302
1303         /*
1304          * With perf record core.cpus is usually NULL.
1305          * Use the old method to handle this for now.
1306          */
1307         if (!evlist->core.cpus || cpu_map__is_dummy(evlist->core.cpus)) {
1308                 evlist__for_each_entry_reverse(evlist, evsel)
1309                         evsel__close(evsel);
1310                 return;
1311         }
1312
1313         if (affinity__setup(&affinity) < 0)
1314                 return;
1315
1316         evlist__for_each_cpu(evlist_cpu_itr, evlist, &affinity) {
1317                 perf_evsel__close_cpu(&evlist_cpu_itr.evsel->core,
1318                                       evlist_cpu_itr.cpu_map_idx);
1319         }
1320
1321         affinity__cleanup(&affinity);
1322         evlist__for_each_entry_reverse(evlist, evsel) {
1323                 perf_evsel__free_fd(&evsel->core);
1324                 perf_evsel__free_id(&evsel->core);
1325         }
1326         perf_evlist__reset_id_hash(&evlist->core);
1327 }
1328
1329 static int evlist__create_syswide_maps(struct evlist *evlist)
1330 {
1331         struct perf_cpu_map *cpus;
1332         struct perf_thread_map *threads;
1333         int err = -ENOMEM;
1334
1335         /*
1336          * Try reading /sys/devices/system/cpu/online to get
1337          * an all cpus map.
1338          *
1339          * FIXME: -ENOMEM is the best we can do here, the cpu_map
1340          * code needs an overhaul to properly forward the
1341          * error, and we may not want to do that fallback to a
1342          * default cpu identity map :-\
1343          */
1344         cpus = perf_cpu_map__new(NULL);
1345         if (!cpus)
1346                 goto out;
1347
1348         threads = perf_thread_map__new_dummy();
1349         if (!threads)
1350                 goto out_put;
1351
1352         perf_evlist__set_maps(&evlist->core, cpus, threads);
1353
1354         perf_thread_map__put(threads);
1355 out_put:
1356         perf_cpu_map__put(cpus);
1357 out:
1358         return err;
1359 }
1360
1361 int evlist__open(struct evlist *evlist)
1362 {
1363         struct evsel *evsel;
1364         int err;
1365
1366         /*
1367          * Default: one fd per CPU, all threads, aka systemwide
1368          * as sys_perf_event_open(cpu = -1, thread = -1) is EINVAL
1369          */
1370         if (evlist->core.threads == NULL && evlist->core.cpus == NULL) {
1371                 err = evlist__create_syswide_maps(evlist);
1372                 if (err < 0)
1373                         goto out_err;
1374         }
1375
1376         evlist__update_id_pos(evlist);
1377
1378         evlist__for_each_entry(evlist, evsel) {
1379                 err = evsel__open(evsel, evsel->core.cpus, evsel->core.threads);
1380                 if (err < 0)
1381                         goto out_err;
1382         }
1383
1384         return 0;
1385 out_err:
1386         evlist__close(evlist);
1387         errno = -err;
1388         return err;
1389 }
1390
1391 int evlist__prepare_workload(struct evlist *evlist, struct target *target, const char *argv[],
1392                              bool pipe_output, void (*exec_error)(int signo, siginfo_t *info, void *ucontext))
1393 {
1394         int child_ready_pipe[2], go_pipe[2];
1395         char bf;
1396
1397         if (pipe(child_ready_pipe) < 0) {
1398                 perror("failed to create 'ready' pipe");
1399                 return -1;
1400         }
1401
1402         if (pipe(go_pipe) < 0) {
1403                 perror("failed to create 'go' pipe");
1404                 goto out_close_ready_pipe;
1405         }
1406
1407         evlist->workload.pid = fork();
1408         if (evlist->workload.pid < 0) {
1409                 perror("failed to fork");
1410                 goto out_close_pipes;
1411         }
1412
1413         if (!evlist->workload.pid) {
1414                 int ret;
1415
1416                 if (pipe_output)
1417                         dup2(2, 1);
1418
1419                 signal(SIGTERM, SIG_DFL);
1420
1421                 close(child_ready_pipe[0]);
1422                 close(go_pipe[1]);
1423                 fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
1424
1425                 /*
1426                  * Change the name of this process not to confuse --exclude-perf users
1427                  * that sees 'perf' in the window up to the execvp() and thinks that
1428                  * perf samples are not being excluded.
1429                  */
1430                 prctl(PR_SET_NAME, "perf-exec");
1431
1432                 /*
1433                  * Tell the parent we're ready to go
1434                  */
1435                 close(child_ready_pipe[1]);
1436
1437                 /*
1438                  * Wait until the parent tells us to go.
1439                  */
1440                 ret = read(go_pipe[0], &bf, 1);
1441                 /*
1442                  * The parent will ask for the execvp() to be performed by
1443                  * writing exactly one byte, in workload.cork_fd, usually via
1444                  * evlist__start_workload().
1445                  *
1446                  * For cancelling the workload without actually running it,
1447                  * the parent will just close workload.cork_fd, without writing
1448                  * anything, i.e. read will return zero and we just exit()
1449                  * here.
1450                  */
1451                 if (ret != 1) {
1452                         if (ret == -1)
1453                                 perror("unable to read pipe");
1454                         exit(ret);
1455                 }
1456
1457                 execvp(argv[0], (char **)argv);
1458
1459                 if (exec_error) {
1460                         union sigval val;
1461
1462                         val.sival_int = errno;
1463                         if (sigqueue(getppid(), SIGUSR1, val))
1464                                 perror(argv[0]);
1465                 } else
1466                         perror(argv[0]);
1467                 exit(-1);
1468         }
1469
1470         if (exec_error) {
1471                 struct sigaction act = {
1472                         .sa_flags     = SA_SIGINFO,
1473                         .sa_sigaction = exec_error,
1474                 };
1475                 sigaction(SIGUSR1, &act, NULL);
1476         }
1477
1478         if (target__none(target)) {
1479                 if (evlist->core.threads == NULL) {
1480                         fprintf(stderr, "FATAL: evlist->threads need to be set at this point (%s:%d).\n",
1481                                 __func__, __LINE__);
1482                         goto out_close_pipes;
1483                 }
1484                 perf_thread_map__set_pid(evlist->core.threads, 0, evlist->workload.pid);
1485         }
1486
1487         close(child_ready_pipe[1]);
1488         close(go_pipe[0]);
1489         /*
1490          * wait for child to settle
1491          */
1492         if (read(child_ready_pipe[0], &bf, 1) == -1) {
1493                 perror("unable to read pipe");
1494                 goto out_close_pipes;
1495         }
1496
1497         fcntl(go_pipe[1], F_SETFD, FD_CLOEXEC);
1498         evlist->workload.cork_fd = go_pipe[1];
1499         close(child_ready_pipe[0]);
1500         return 0;
1501
1502 out_close_pipes:
1503         close(go_pipe[0]);
1504         close(go_pipe[1]);
1505 out_close_ready_pipe:
1506         close(child_ready_pipe[0]);
1507         close(child_ready_pipe[1]);
1508         return -1;
1509 }
1510
1511 int evlist__start_workload(struct evlist *evlist)
1512 {
1513         if (evlist->workload.cork_fd > 0) {
1514                 char bf = 0;
1515                 int ret;
1516                 /*
1517                  * Remove the cork, let it rip!
1518                  */
1519                 ret = write(evlist->workload.cork_fd, &bf, 1);
1520                 if (ret < 0)
1521                         perror("unable to write to pipe");
1522
1523                 close(evlist->workload.cork_fd);
1524                 return ret;
1525         }
1526
1527         return 0;
1528 }
1529
1530 int evlist__parse_sample(struct evlist *evlist, union perf_event *event, struct perf_sample *sample)
1531 {
1532         struct evsel *evsel = evlist__event2evsel(evlist, event);
1533
1534         if (!evsel)
1535                 return -EFAULT;
1536         return evsel__parse_sample(evsel, event, sample);
1537 }
1538
1539 int evlist__parse_sample_timestamp(struct evlist *evlist, union perf_event *event, u64 *timestamp)
1540 {
1541         struct evsel *evsel = evlist__event2evsel(evlist, event);
1542
1543         if (!evsel)
1544                 return -EFAULT;
1545         return evsel__parse_sample_timestamp(evsel, event, timestamp);
1546 }
1547
1548 int evlist__strerror_open(struct evlist *evlist, int err, char *buf, size_t size)
1549 {
1550         int printed, value;
1551         char sbuf[STRERR_BUFSIZE], *emsg = str_error_r(err, sbuf, sizeof(sbuf));
1552
1553         switch (err) {
1554         case EACCES:
1555         case EPERM:
1556                 printed = scnprintf(buf, size,
1557                                     "Error:\t%s.\n"
1558                                     "Hint:\tCheck /proc/sys/kernel/perf_event_paranoid setting.", emsg);
1559
1560                 value = perf_event_paranoid();
1561
1562                 printed += scnprintf(buf + printed, size - printed, "\nHint:\t");
1563
1564                 if (value >= 2) {
1565                         printed += scnprintf(buf + printed, size - printed,
1566                                              "For your workloads it needs to be <= 1\nHint:\t");
1567                 }
1568                 printed += scnprintf(buf + printed, size - printed,
1569                                      "For system wide tracing it needs to be set to -1.\n");
1570
1571                 printed += scnprintf(buf + printed, size - printed,
1572                                     "Hint:\tTry: 'sudo sh -c \"echo -1 > /proc/sys/kernel/perf_event_paranoid\"'\n"
1573                                     "Hint:\tThe current value is %d.", value);
1574                 break;
1575         case EINVAL: {
1576                 struct evsel *first = evlist__first(evlist);
1577                 int max_freq;
1578
1579                 if (sysctl__read_int("kernel/perf_event_max_sample_rate", &max_freq) < 0)
1580                         goto out_default;
1581
1582                 if (first->core.attr.sample_freq < (u64)max_freq)
1583                         goto out_default;
1584
1585                 printed = scnprintf(buf, size,
1586                                     "Error:\t%s.\n"
1587                                     "Hint:\tCheck /proc/sys/kernel/perf_event_max_sample_rate.\n"
1588                                     "Hint:\tThe current value is %d and %" PRIu64 " is being requested.",
1589                                     emsg, max_freq, first->core.attr.sample_freq);
1590                 break;
1591         }
1592         default:
1593 out_default:
1594                 scnprintf(buf, size, "%s", emsg);
1595                 break;
1596         }
1597
1598         return 0;
1599 }
1600
1601 int evlist__strerror_mmap(struct evlist *evlist, int err, char *buf, size_t size)
1602 {
1603         char sbuf[STRERR_BUFSIZE], *emsg = str_error_r(err, sbuf, sizeof(sbuf));
1604         int pages_attempted = evlist->core.mmap_len / 1024, pages_max_per_user, printed = 0;
1605
1606         switch (err) {
1607         case EPERM:
1608                 sysctl__read_int("kernel/perf_event_mlock_kb", &pages_max_per_user);
1609                 printed += scnprintf(buf + printed, size - printed,
1610                                      "Error:\t%s.\n"
1611                                      "Hint:\tCheck /proc/sys/kernel/perf_event_mlock_kb (%d kB) setting.\n"
1612                                      "Hint:\tTried using %zd kB.\n",
1613                                      emsg, pages_max_per_user, pages_attempted);
1614
1615                 if (pages_attempted >= pages_max_per_user) {
1616                         printed += scnprintf(buf + printed, size - printed,
1617                                              "Hint:\tTry 'sudo sh -c \"echo %d > /proc/sys/kernel/perf_event_mlock_kb\"', or\n",
1618                                              pages_max_per_user + pages_attempted);
1619                 }
1620
1621                 printed += scnprintf(buf + printed, size - printed,
1622                                      "Hint:\tTry using a smaller -m/--mmap-pages value.");
1623                 break;
1624         default:
1625                 scnprintf(buf, size, "%s", emsg);
1626                 break;
1627         }
1628
1629         return 0;
1630 }
1631
1632 void evlist__to_front(struct evlist *evlist, struct evsel *move_evsel)
1633 {
1634         struct evsel *evsel, *n;
1635         LIST_HEAD(move);
1636
1637         if (move_evsel == evlist__first(evlist))
1638                 return;
1639
1640         evlist__for_each_entry_safe(evlist, n, evsel) {
1641                 if (evsel__leader(evsel) == evsel__leader(move_evsel))
1642                         list_move_tail(&evsel->core.node, &move);
1643         }
1644
1645         list_splice(&move, &evlist->core.entries);
1646 }
1647
1648 struct evsel *evlist__get_tracking_event(struct evlist *evlist)
1649 {
1650         struct evsel *evsel;
1651
1652         evlist__for_each_entry(evlist, evsel) {
1653                 if (evsel->tracking)
1654                         return evsel;
1655         }
1656
1657         return evlist__first(evlist);
1658 }
1659
1660 void evlist__set_tracking_event(struct evlist *evlist, struct evsel *tracking_evsel)
1661 {
1662         struct evsel *evsel;
1663
1664         if (tracking_evsel->tracking)
1665                 return;
1666
1667         evlist__for_each_entry(evlist, evsel) {
1668                 if (evsel != tracking_evsel)
1669                         evsel->tracking = false;
1670         }
1671
1672         tracking_evsel->tracking = true;
1673 }
1674
1675 struct evsel *evlist__find_evsel_by_str(struct evlist *evlist, const char *str)
1676 {
1677         struct evsel *evsel;
1678
1679         evlist__for_each_entry(evlist, evsel) {
1680                 if (!evsel->name)
1681                         continue;
1682                 if (strcmp(str, evsel->name) == 0)
1683                         return evsel;
1684         }
1685
1686         return NULL;
1687 }
1688
1689 void evlist__toggle_bkw_mmap(struct evlist *evlist, enum bkw_mmap_state state)
1690 {
1691         enum bkw_mmap_state old_state = evlist->bkw_mmap_state;
1692         enum action {
1693                 NONE,
1694                 PAUSE,
1695                 RESUME,
1696         } action = NONE;
1697
1698         if (!evlist->overwrite_mmap)
1699                 return;
1700
1701         switch (old_state) {
1702         case BKW_MMAP_NOTREADY: {
1703                 if (state != BKW_MMAP_RUNNING)
1704                         goto state_err;
1705                 break;
1706         }
1707         case BKW_MMAP_RUNNING: {
1708                 if (state != BKW_MMAP_DATA_PENDING)
1709                         goto state_err;
1710                 action = PAUSE;
1711                 break;
1712         }
1713         case BKW_MMAP_DATA_PENDING: {
1714                 if (state != BKW_MMAP_EMPTY)
1715                         goto state_err;
1716                 break;
1717         }
1718         case BKW_MMAP_EMPTY: {
1719                 if (state != BKW_MMAP_RUNNING)
1720                         goto state_err;
1721                 action = RESUME;
1722                 break;
1723         }
1724         default:
1725                 WARN_ONCE(1, "Shouldn't get there\n");
1726         }
1727
1728         evlist->bkw_mmap_state = state;
1729
1730         switch (action) {
1731         case PAUSE:
1732                 evlist__pause(evlist);
1733                 break;
1734         case RESUME:
1735                 evlist__resume(evlist);
1736                 break;
1737         case NONE:
1738         default:
1739                 break;
1740         }
1741
1742 state_err:
1743         return;
1744 }
1745
1746 bool evlist__exclude_kernel(struct evlist *evlist)
1747 {
1748         struct evsel *evsel;
1749
1750         evlist__for_each_entry(evlist, evsel) {
1751                 if (!evsel->core.attr.exclude_kernel)
1752                         return false;
1753         }
1754
1755         return true;
1756 }
1757
1758 /*
1759  * Events in data file are not collect in groups, but we still want
1760  * the group display. Set the artificial group and set the leader's
1761  * forced_leader flag to notify the display code.
1762  */
1763 void evlist__force_leader(struct evlist *evlist)
1764 {
1765         if (!evlist->core.nr_groups) {
1766                 struct evsel *leader = evlist__first(evlist);
1767
1768                 evlist__set_leader(evlist);
1769                 leader->forced_leader = true;
1770         }
1771 }
1772
1773 struct evsel *evlist__reset_weak_group(struct evlist *evsel_list, struct evsel *evsel, bool close)
1774 {
1775         struct evsel *c2, *leader;
1776         bool is_open = true;
1777
1778         leader = evsel__leader(evsel);
1779
1780         pr_debug("Weak group for %s/%d failed\n",
1781                         leader->name, leader->core.nr_members);
1782
1783         /*
1784          * for_each_group_member doesn't work here because it doesn't
1785          * include the first entry.
1786          */
1787         evlist__for_each_entry(evsel_list, c2) {
1788                 if (c2 == evsel)
1789                         is_open = false;
1790                 if (evsel__has_leader(c2, leader)) {
1791                         if (is_open && close)
1792                                 perf_evsel__close(&c2->core);
1793                         evsel__set_leader(c2, c2);
1794                         c2->core.nr_members = 0;
1795                         /*
1796                          * Set this for all former members of the group
1797                          * to indicate they get reopened.
1798                          */
1799                         c2->reset_group = true;
1800                 }
1801         }
1802         return leader;
1803 }
1804
1805 static int evlist__parse_control_fifo(const char *str, int *ctl_fd, int *ctl_fd_ack, bool *ctl_fd_close)
1806 {
1807         char *s, *p;
1808         int ret = 0, fd;
1809
1810         if (strncmp(str, "fifo:", 5))
1811                 return -EINVAL;
1812
1813         str += 5;
1814         if (!*str || *str == ',')
1815                 return -EINVAL;
1816
1817         s = strdup(str);
1818         if (!s)
1819                 return -ENOMEM;
1820
1821         p = strchr(s, ',');
1822         if (p)
1823                 *p = '\0';
1824
1825         /*
1826          * O_RDWR avoids POLLHUPs which is necessary to allow the other
1827          * end of a FIFO to be repeatedly opened and closed.
1828          */
1829         fd = open(s, O_RDWR | O_NONBLOCK | O_CLOEXEC);
1830         if (fd < 0) {
1831                 pr_err("Failed to open '%s'\n", s);
1832                 ret = -errno;
1833                 goto out_free;
1834         }
1835         *ctl_fd = fd;
1836         *ctl_fd_close = true;
1837
1838         if (p && *++p) {
1839                 /* O_RDWR | O_NONBLOCK means the other end need not be open */
1840                 fd = open(p, O_RDWR | O_NONBLOCK | O_CLOEXEC);
1841                 if (fd < 0) {
1842                         pr_err("Failed to open '%s'\n", p);
1843                         ret = -errno;
1844                         goto out_free;
1845                 }
1846                 *ctl_fd_ack = fd;
1847         }
1848
1849 out_free:
1850         free(s);
1851         return ret;
1852 }
1853
1854 int evlist__parse_control(const char *str, int *ctl_fd, int *ctl_fd_ack, bool *ctl_fd_close)
1855 {
1856         char *comma = NULL, *endptr = NULL;
1857
1858         *ctl_fd_close = false;
1859
1860         if (strncmp(str, "fd:", 3))
1861                 return evlist__parse_control_fifo(str, ctl_fd, ctl_fd_ack, ctl_fd_close);
1862
1863         *ctl_fd = strtoul(&str[3], &endptr, 0);
1864         if (endptr == &str[3])
1865                 return -EINVAL;
1866
1867         comma = strchr(str, ',');
1868         if (comma) {
1869                 if (endptr != comma)
1870                         return -EINVAL;
1871
1872                 *ctl_fd_ack = strtoul(comma + 1, &endptr, 0);
1873                 if (endptr == comma + 1 || *endptr != '\0')
1874                         return -EINVAL;
1875         }
1876
1877         return 0;
1878 }
1879
1880 void evlist__close_control(int ctl_fd, int ctl_fd_ack, bool *ctl_fd_close)
1881 {
1882         if (*ctl_fd_close) {
1883                 *ctl_fd_close = false;
1884                 close(ctl_fd);
1885                 if (ctl_fd_ack >= 0)
1886                         close(ctl_fd_ack);
1887         }
1888 }
1889
1890 int evlist__initialize_ctlfd(struct evlist *evlist, int fd, int ack)
1891 {
1892         if (fd == -1) {
1893                 pr_debug("Control descriptor is not initialized\n");
1894                 return 0;
1895         }
1896
1897         evlist->ctl_fd.pos = perf_evlist__add_pollfd(&evlist->core, fd, NULL, POLLIN,
1898                                                      fdarray_flag__nonfilterable);
1899         if (evlist->ctl_fd.pos < 0) {
1900                 evlist->ctl_fd.pos = -1;
1901                 pr_err("Failed to add ctl fd entry: %m\n");
1902                 return -1;
1903         }
1904
1905         evlist->ctl_fd.fd = fd;
1906         evlist->ctl_fd.ack = ack;
1907
1908         return 0;
1909 }
1910
1911 bool evlist__ctlfd_initialized(struct evlist *evlist)
1912 {
1913         return evlist->ctl_fd.pos >= 0;
1914 }
1915
1916 int evlist__finalize_ctlfd(struct evlist *evlist)
1917 {
1918         struct pollfd *entries = evlist->core.pollfd.entries;
1919
1920         if (!evlist__ctlfd_initialized(evlist))
1921                 return 0;
1922
1923         entries[evlist->ctl_fd.pos].fd = -1;
1924         entries[evlist->ctl_fd.pos].events = 0;
1925         entries[evlist->ctl_fd.pos].revents = 0;
1926
1927         evlist->ctl_fd.pos = -1;
1928         evlist->ctl_fd.ack = -1;
1929         evlist->ctl_fd.fd = -1;
1930
1931         return 0;
1932 }
1933
1934 static int evlist__ctlfd_recv(struct evlist *evlist, enum evlist_ctl_cmd *cmd,
1935                               char *cmd_data, size_t data_size)
1936 {
1937         int err;
1938         char c;
1939         size_t bytes_read = 0;
1940
1941         *cmd = EVLIST_CTL_CMD_UNSUPPORTED;
1942         memset(cmd_data, 0, data_size);
1943         data_size--;
1944
1945         do {
1946                 err = read(evlist->ctl_fd.fd, &c, 1);
1947                 if (err > 0) {
1948                         if (c == '\n' || c == '\0')
1949                                 break;
1950                         cmd_data[bytes_read++] = c;
1951                         if (bytes_read == data_size)
1952                                 break;
1953                         continue;
1954                 } else if (err == -1) {
1955                         if (errno == EINTR)
1956                                 continue;
1957                         if (errno == EAGAIN || errno == EWOULDBLOCK)
1958                                 err = 0;
1959                         else
1960                                 pr_err("Failed to read from ctlfd %d: %m\n", evlist->ctl_fd.fd);
1961                 }
1962                 break;
1963         } while (1);
1964
1965         pr_debug("Message from ctl_fd: \"%s%s\"\n", cmd_data,
1966                  bytes_read == data_size ? "" : c == '\n' ? "\\n" : "\\0");
1967
1968         if (bytes_read > 0) {
1969                 if (!strncmp(cmd_data, EVLIST_CTL_CMD_ENABLE_TAG,
1970                              (sizeof(EVLIST_CTL_CMD_ENABLE_TAG)-1))) {
1971                         *cmd = EVLIST_CTL_CMD_ENABLE;
1972                 } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_DISABLE_TAG,
1973                                     (sizeof(EVLIST_CTL_CMD_DISABLE_TAG)-1))) {
1974                         *cmd = EVLIST_CTL_CMD_DISABLE;
1975                 } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_SNAPSHOT_TAG,
1976                                     (sizeof(EVLIST_CTL_CMD_SNAPSHOT_TAG)-1))) {
1977                         *cmd = EVLIST_CTL_CMD_SNAPSHOT;
1978                         pr_debug("is snapshot\n");
1979                 } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_EVLIST_TAG,
1980                                     (sizeof(EVLIST_CTL_CMD_EVLIST_TAG)-1))) {
1981                         *cmd = EVLIST_CTL_CMD_EVLIST;
1982                 } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_STOP_TAG,
1983                                     (sizeof(EVLIST_CTL_CMD_STOP_TAG)-1))) {
1984                         *cmd = EVLIST_CTL_CMD_STOP;
1985                 } else if (!strncmp(cmd_data, EVLIST_CTL_CMD_PING_TAG,
1986                                     (sizeof(EVLIST_CTL_CMD_PING_TAG)-1))) {
1987                         *cmd = EVLIST_CTL_CMD_PING;
1988                 }
1989         }
1990
1991         return bytes_read ? (int)bytes_read : err;
1992 }
1993
1994 int evlist__ctlfd_ack(struct evlist *evlist)
1995 {
1996         int err;
1997
1998         if (evlist->ctl_fd.ack == -1)
1999                 return 0;
2000
2001         err = write(evlist->ctl_fd.ack, EVLIST_CTL_CMD_ACK_TAG,
2002                     sizeof(EVLIST_CTL_CMD_ACK_TAG));
2003         if (err == -1)
2004                 pr_err("failed to write to ctl_ack_fd %d: %m\n", evlist->ctl_fd.ack);
2005
2006         return err;
2007 }
2008
2009 static int get_cmd_arg(char *cmd_data, size_t cmd_size, char **arg)
2010 {
2011         char *data = cmd_data + cmd_size;
2012
2013         /* no argument */
2014         if (!*data)
2015                 return 0;
2016
2017         /* there's argument */
2018         if (*data == ' ') {
2019                 *arg = data + 1;
2020                 return 1;
2021         }
2022
2023         /* malformed */
2024         return -1;
2025 }
2026
2027 static int evlist__ctlfd_enable(struct evlist *evlist, char *cmd_data, bool enable)
2028 {
2029         struct evsel *evsel;
2030         char *name;
2031         int err;
2032
2033         err = get_cmd_arg(cmd_data,
2034                           enable ? sizeof(EVLIST_CTL_CMD_ENABLE_TAG) - 1 :
2035                                    sizeof(EVLIST_CTL_CMD_DISABLE_TAG) - 1,
2036                           &name);
2037         if (err < 0) {
2038                 pr_info("failed: wrong command\n");
2039                 return -1;
2040         }
2041
2042         if (err) {
2043                 evsel = evlist__find_evsel_by_str(evlist, name);
2044                 if (evsel) {
2045                         if (enable)
2046                                 evlist__enable_evsel(evlist, name);
2047                         else
2048                                 evlist__disable_evsel(evlist, name);
2049                         pr_info("Event %s %s\n", evsel->name,
2050                                 enable ? "enabled" : "disabled");
2051                 } else {
2052                         pr_info("failed: can't find '%s' event\n", name);
2053                 }
2054         } else {
2055                 if (enable) {
2056                         evlist__enable(evlist);
2057                         pr_info(EVLIST_ENABLED_MSG);
2058                 } else {
2059                         evlist__disable(evlist);
2060                         pr_info(EVLIST_DISABLED_MSG);
2061                 }
2062         }
2063
2064         return 0;
2065 }
2066
2067 static int evlist__ctlfd_list(struct evlist *evlist, char *cmd_data)
2068 {
2069         struct perf_attr_details details = { .verbose = false, };
2070         struct evsel *evsel;
2071         char *arg;
2072         int err;
2073
2074         err = get_cmd_arg(cmd_data,
2075                           sizeof(EVLIST_CTL_CMD_EVLIST_TAG) - 1,
2076                           &arg);
2077         if (err < 0) {
2078                 pr_info("failed: wrong command\n");
2079                 return -1;
2080         }
2081
2082         if (err) {
2083                 if (!strcmp(arg, "-v")) {
2084                         details.verbose = true;
2085                 } else if (!strcmp(arg, "-g")) {
2086                         details.event_group = true;
2087                 } else if (!strcmp(arg, "-F")) {
2088                         details.freq = true;
2089                 } else {
2090                         pr_info("failed: wrong command\n");
2091                         return -1;
2092                 }
2093         }
2094
2095         evlist__for_each_entry(evlist, evsel)
2096                 evsel__fprintf(evsel, &details, stderr);
2097
2098         return 0;
2099 }
2100
2101 int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd)
2102 {
2103         int err = 0;
2104         char cmd_data[EVLIST_CTL_CMD_MAX_LEN];
2105         int ctlfd_pos = evlist->ctl_fd.pos;
2106         struct pollfd *entries = evlist->core.pollfd.entries;
2107
2108         if (!evlist__ctlfd_initialized(evlist) || !entries[ctlfd_pos].revents)
2109                 return 0;
2110
2111         if (entries[ctlfd_pos].revents & POLLIN) {
2112                 err = evlist__ctlfd_recv(evlist, cmd, cmd_data,
2113                                          EVLIST_CTL_CMD_MAX_LEN);
2114                 if (err > 0) {
2115                         switch (*cmd) {
2116                         case EVLIST_CTL_CMD_ENABLE:
2117                         case EVLIST_CTL_CMD_DISABLE:
2118                                 err = evlist__ctlfd_enable(evlist, cmd_data,
2119                                                            *cmd == EVLIST_CTL_CMD_ENABLE);
2120                                 break;
2121                         case EVLIST_CTL_CMD_EVLIST:
2122                                 err = evlist__ctlfd_list(evlist, cmd_data);
2123                                 break;
2124                         case EVLIST_CTL_CMD_SNAPSHOT:
2125                         case EVLIST_CTL_CMD_STOP:
2126                         case EVLIST_CTL_CMD_PING:
2127                                 break;
2128                         case EVLIST_CTL_CMD_ACK:
2129                         case EVLIST_CTL_CMD_UNSUPPORTED:
2130                         default:
2131                                 pr_debug("ctlfd: unsupported %d\n", *cmd);
2132                                 break;
2133                         }
2134                         if (!(*cmd == EVLIST_CTL_CMD_ACK || *cmd == EVLIST_CTL_CMD_UNSUPPORTED ||
2135                               *cmd == EVLIST_CTL_CMD_SNAPSHOT))
2136                                 evlist__ctlfd_ack(evlist);
2137                 }
2138         }
2139
2140         if (entries[ctlfd_pos].revents & (POLLHUP | POLLERR))
2141                 evlist__finalize_ctlfd(evlist);
2142         else
2143                 entries[ctlfd_pos].revents = 0;
2144
2145         return err;
2146 }
2147
2148 struct evsel *evlist__find_evsel(struct evlist *evlist, int idx)
2149 {
2150         struct evsel *evsel;
2151
2152         evlist__for_each_entry(evlist, evsel) {
2153                 if (evsel->core.idx == idx)
2154                         return evsel;
2155         }
2156         return NULL;
2157 }
2158
2159 int evlist__scnprintf_evsels(struct evlist *evlist, size_t size, char *bf)
2160 {
2161         struct evsel *evsel;
2162         int printed = 0;
2163
2164         evlist__for_each_entry(evlist, evsel) {
2165                 if (evsel__is_dummy_event(evsel))
2166                         continue;
2167                 if (size > (strlen(evsel__name(evsel)) + (printed ? 2 : 1))) {
2168                         printed += scnprintf(bf + printed, size - printed, "%s%s", printed ? "," : "", evsel__name(evsel));
2169                 } else {
2170                         printed += scnprintf(bf + printed, size - printed, "%s...", printed ? "," : "");
2171                         break;
2172                 }
2173         }
2174
2175         return printed;
2176 }
2177
2178 void evlist__check_mem_load_aux(struct evlist *evlist)
2179 {
2180         struct evsel *leader, *evsel, *pos;
2181
2182         /*
2183          * For some platforms, the 'mem-loads' event is required to use
2184          * together with 'mem-loads-aux' within a group and 'mem-loads-aux'
2185          * must be the group leader. Now we disable this group before reporting
2186          * because 'mem-loads-aux' is just an auxiliary event. It doesn't carry
2187          * any valid memory load information.
2188          */
2189         evlist__for_each_entry(evlist, evsel) {
2190                 leader = evsel__leader(evsel);
2191                 if (leader == evsel)
2192                         continue;
2193
2194                 if (leader->name && strstr(leader->name, "mem-loads-aux")) {
2195                         for_each_group_evsel(pos, leader) {
2196                                 evsel__set_leader(pos, pos);
2197                                 pos->core.nr_members = 0;
2198                         }
2199                 }
2200         }
2201 }