tools/perf/util/evlist.c

   1 /*
   2  * Copyright (C) 2011, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
   3  *
   4  * Parts came from builtin-{top,stat,record}.c, see those files for further
   5  * copyright notes.
   6  *
   7  * Released under the GPL v2. (and only v2, not any later version)
   8  */
   9 #include "util.h"
  10 #include <api/fs/debugfs.h>
  11 #include <poll.h>
  12 #include "cpumap.h"
  13 #include "thread_map.h"
  14 #include "target.h"
  15 #include "evlist.h"
  16 #include "evsel.h"
  17 #include "debug.h"
  18 #include <unistd.h>
  19
  20 #include "parse-events.h"
  21 #include "parse-options.h"
  22
  23 #include <sys/mman.h>
  24
  25 #include <linux/bitops.h>
  26 #include <linux/hash.h>
  27
  28 static void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx);
  29 static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx);
  30
  31 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
  32 #define SID(e, x, y) xyarray__entry(e->sample_id, x, y)
  33
  34 void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus,
  35                        struct thread_map *threads)
  36 {
  37         int i;
  38
  39         for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
  40                 INIT_HLIST_HEAD(&evlist->heads[i]);
  41         INIT_LIST_HEAD(&evlist->entries);
  42         perf_evlist__set_maps(evlist, cpus, threads);
  43         fdarray__init(&evlist->pollfd, 64);
  44         evlist->workload.pid = -1;
  45 }
  46
  47 struct perf_evlist *perf_evlist__new(void)
  48 {
  49         struct perf_evlist *evlist = zalloc(sizeof(*evlist));
  50
  51         if (evlist != NULL)
  52                 perf_evlist__init(evlist, NULL, NULL);
  53
  54         return evlist;
  55 }
  56
  57 struct perf_evlist *perf_evlist__new_default(void)
  58 {
  59         struct perf_evlist *evlist = perf_evlist__new();
  60
  61         if (evlist && perf_evlist__add_default(evlist)) {
  62                 perf_evlist__delete(evlist);
  63                 evlist = NULL;
  64         }
  65
  66         return evlist;
  67 }
  68
  69 /**
  70  * perf_evlist__set_id_pos - set the positions of event ids.
  71  * @evlist: selected event list
  72  *
  73  * Events with compatible sample types all have the same id_pos
  74  * and is_pos.  For convenience, put a copy on evlist.
  75  */
  76 void perf_evlist__set_id_pos(struct perf_evlist *evlist)
  77 {
  78         struct perf_evsel *first = perf_evlist__first(evlist);
  79
  80         evlist->id_pos = first->id_pos;
  81         evlist->is_pos = first->is_pos;
  82 }
  83
  84 static void perf_evlist__update_id_pos(struct perf_evlist *evlist)
  85 {
  86         struct perf_evsel *evsel;
  87
  88         evlist__for_each(evlist, evsel)
  89                 perf_evsel__calc_id_pos(evsel);
  90
  91         perf_evlist__set_id_pos(evlist);
  92 }
  93
  94 static void perf_evlist__purge(struct perf_evlist *evlist)
  95 {
  96         struct perf_evsel *pos, *n;
  97
  98         evlist__for_each_safe(evlist, n, pos) {
  99                 list_del_init(&pos->node);
 100                 perf_evsel__delete(pos);
 101         }
 102
 103         evlist->nr_entries = 0;
 104 }
 105
 106 void perf_evlist__exit(struct perf_evlist *evlist)
 107 {
 108         zfree(&evlist->mmap);
 109         fdarray__exit(&evlist->pollfd);
 110 }
 111
 112 void perf_evlist__delete(struct perf_evlist *evlist)
 113 {
 114         perf_evlist__munmap(evlist);
 115         perf_evlist__close(evlist);
 116         cpu_map__delete(evlist->cpus);
 117         thread_map__delete(evlist->threads);
 118         evlist->cpus = NULL;
 119         evlist->threads = NULL;
 120         perf_evlist__purge(evlist);
 121         perf_evlist__exit(evlist);
 122         free(evlist);
 123 }
 124
 125 void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry)
 126 {
 127         list_add_tail(&entry->node, &evlist->entries);
 128         entry->idx = evlist->nr_entries;
 129         entry->tracking = !entry->idx;
 130
 131         if (!evlist->nr_entries++)
 132                 perf_evlist__set_id_pos(evlist);
 133 }
 134
 135 void perf_evlist__splice_list_tail(struct perf_evlist *evlist,
 136                                    struct list_head *list,
 137                                    int nr_entries)
 138 {
 139         bool set_id_pos = !evlist->nr_entries;
 140
 141         list_splice_tail(list, &evlist->entries);
 142         evlist->nr_entries += nr_entries;
 143         if (set_id_pos)
 144                 perf_evlist__set_id_pos(evlist);
 145 }
 146
 147 void __perf_evlist__set_leader(struct list_head *list)
 148 {
 149         struct perf_evsel *evsel, *leader;
 150
 151         leader = list_entry(list->next, struct perf_evsel, node);
 152         evsel = list_entry(list->prev, struct perf_evsel, node);
 153
 154         leader->nr_members = evsel->idx - leader->idx + 1;
 155
 156         __evlist__for_each(list, evsel) {
 157                 evsel->leader = leader;
 158         }
 159 }
 160
 161 void perf_evlist__set_leader(struct perf_evlist *evlist)
 162 {
 163         if (evlist->nr_entries) {
 164                 evlist->nr_groups = evlist->nr_entries > 1 ? 1 : 0;
 165                 __perf_evlist__set_leader(&evlist->entries);
 166         }
 167 }
 168
 169 int perf_evlist__add_default(struct perf_evlist *evlist)
 170 {
 171         struct perf_event_attr attr = {
 172                 .type = PERF_TYPE_HARDWARE,
 173                 .config = PERF_COUNT_HW_CPU_CYCLES,
 174         };
 175         struct perf_evsel *evsel;
 176
 177         event_attr_init(&attr);
 178
 179         evsel = perf_evsel__new(&attr);
 180         if (evsel == NULL)
 181                 goto error;
 182
 183         /* use strdup() because free(evsel) assumes name is allocated */
 184         evsel->name = strdup("cycles");
 185         if (!evsel->name)
 186                 goto error_free;
 187
 188         perf_evlist__add(evlist, evsel);
 189         return 0;
 190 error_free:
 191         perf_evsel__delete(evsel);
 192 error:
 193         return -ENOMEM;
 194 }
 195
 196 static int perf_evlist__add_attrs(struct perf_evlist *evlist,
 197                                   struct perf_event_attr *attrs, size_t nr_attrs)
 198 {
 199         struct perf_evsel *evsel, *n;
 200         LIST_HEAD(head);
 201         size_t i;
 202
 203         for (i = 0; i < nr_attrs; i++) {
 204                 evsel = perf_evsel__new_idx(attrs + i, evlist->nr_entries + i);
 205                 if (evsel == NULL)
 206                         goto out_delete_partial_list;
 207                 list_add_tail(&evsel->node, &head);
 208         }
 209
 210         perf_evlist__splice_list_tail(evlist, &head, nr_attrs);
 211
 212         return 0;
 213
 214 out_delete_partial_list:
 215         __evlist__for_each_safe(&head, n, evsel)
 216                 perf_evsel__delete(evsel);
 217         return -1;
 218 }
 219
 220 int __perf_evlist__add_default_attrs(struct perf_evlist *evlist,
 221                                      struct perf_event_attr *attrs, size_t nr_attrs)
 222 {
 223         size_t i;
 224
 225         for (i = 0; i < nr_attrs; i++)
 226                 event_attr_init(attrs + i);
 227
 228         return perf_evlist__add_attrs(evlist, attrs, nr_attrs);
 229 }
 230
 231 struct perf_evsel *
 232 perf_evlist__find_tracepoint_by_id(struct perf_evlist *evlist, int id)
 233 {
 234         struct perf_evsel *evsel;
 235
 236         evlist__for_each(evlist, evsel) {
 237                 if (evsel->attr.type   == PERF_TYPE_TRACEPOINT &&
 238                     (int)evsel->attr.config == id)
 239                         return evsel;
 240         }
 241
 242         return NULL;
 243 }
 244
 245 struct perf_evsel *
 246 perf_evlist__find_tracepoint_by_name(struct perf_evlist *evlist,
 247                                      const char *name)
 248 {
 249         struct perf_evsel *evsel;
 250
 251         evlist__for_each(evlist, evsel) {
 252                 if ((evsel->attr.type == PERF_TYPE_TRACEPOINT) &&
 253                     (strcmp(evsel->name, name) == 0))
 254                         return evsel;
 255         }
 256
 257         return NULL;
 258 }
 259
 260 int perf_evlist__add_newtp(struct perf_evlist *evlist,
 261                            const char *sys, const char *name, void *handler)
 262 {
 263         struct perf_evsel *evsel = perf_evsel__newtp(sys, name);
 264
 265         if (evsel == NULL)
 266                 return -1;
 267
 268         evsel->handler = handler;
 269         perf_evlist__add(evlist, evsel);
 270         return 0;
 271 }
 272
 273 static int perf_evlist__nr_threads(struct perf_evlist *evlist,
 274                                    struct perf_evsel *evsel)
 275 {
 276         if (evsel->system_wide)
 277                 return 1;
 278         else
 279                 return thread_map__nr(evlist->threads);
 280 }
 281
 282 void perf_evlist__disable(struct perf_evlist *evlist)
 283 {
 284         int cpu, thread;
 285         struct perf_evsel *pos;
 286         int nr_cpus = cpu_map__nr(evlist->cpus);
 287         int nr_threads;
 288
 289         for (cpu = 0; cpu < nr_cpus; cpu++) {
 290                 evlist__for_each(evlist, pos) {
 291                         if (!perf_evsel__is_group_leader(pos) || !pos->fd)
 292                                 continue;
 293                         nr_threads = perf_evlist__nr_threads(evlist, pos);
 294                         for (thread = 0; thread < nr_threads; thread++)
 295                                 ioctl(FD(pos, cpu, thread),
 296                                       PERF_EVENT_IOC_DISABLE, 0);
 297                 }
 298         }
 299 }
 300
 301 void perf_evlist__enable(struct perf_evlist *evlist)
 302 {
 303         int cpu, thread;
 304         struct perf_evsel *pos;
 305         int nr_cpus = cpu_map__nr(evlist->cpus);
 306         int nr_threads;
 307
 308         for (cpu = 0; cpu < nr_cpus; cpu++) {
 309                 evlist__for_each(evlist, pos) {
 310                         if (!perf_evsel__is_group_leader(pos) || !pos->fd)
 311                                 continue;
 312                         nr_threads = perf_evlist__nr_threads(evlist, pos);
 313                         for (thread = 0; thread < nr_threads; thread++)
 314                                 ioctl(FD(pos, cpu, thread),
 315                                       PERF_EVENT_IOC_ENABLE, 0);
 316                 }
 317         }
 318 }
 319
 320 int perf_evlist__disable_event(struct perf_evlist *evlist,
 321                                struct perf_evsel *evsel)
 322 {
 323         int cpu, thread, err;
 324         int nr_cpus = cpu_map__nr(evlist->cpus);
 325         int nr_threads = perf_evlist__nr_threads(evlist, evsel);
 326
 327         if (!evsel->fd)
 328                 return 0;
 329
 330         for (cpu = 0; cpu < nr_cpus; cpu++) {
 331                 for (thread = 0; thread < nr_threads; thread++) {
 332                         err = ioctl(FD(evsel, cpu, thread),
 333                                     PERF_EVENT_IOC_DISABLE, 0);
 334                         if (err)
 335                                 return err;
 336                 }
 337         }
 338         return 0;
 339 }
 340
 341 int perf_evlist__enable_event(struct perf_evlist *evlist,
 342                               struct perf_evsel *evsel)
 343 {
 344         int cpu, thread, err;
 345         int nr_cpus = cpu_map__nr(evlist->cpus);
 346         int nr_threads = perf_evlist__nr_threads(evlist, evsel);
 347
 348         if (!evsel->fd)
 349                 return -EINVAL;
 350
 351         for (cpu = 0; cpu < nr_cpus; cpu++) {
 352                 for (thread = 0; thread < nr_threads; thread++) {
 353                         err = ioctl(FD(evsel, cpu, thread),
 354                                     PERF_EVENT_IOC_ENABLE, 0);
 355                         if (err)
 356                                 return err;
 357                 }
 358         }
 359         return 0;
 360 }
 361
 362 static int perf_evlist__enable_event_cpu(struct perf_evlist *evlist,
 363                                          struct perf_evsel *evsel, int cpu)
 364 {
 365         int thread, err;
 366         int nr_threads = perf_evlist__nr_threads(evlist, evsel);
 367
 368         if (!evsel->fd)
 369                 return -EINVAL;
 370
 371         for (thread = 0; thread < nr_threads; thread++) {
 372                 err = ioctl(FD(evsel, cpu, thread),
 373                             PERF_EVENT_IOC_ENABLE, 0);
 374                 if (err)
 375                         return err;
 376         }
 377         return 0;
 378 }
 379
 380 static int perf_evlist__enable_event_thread(struct perf_evlist *evlist,
 381                                             struct perf_evsel *evsel,
 382                                             int thread)
 383 {
 384         int cpu, err;
 385         int nr_cpus = cpu_map__nr(evlist->cpus);
 386
 387         if (!evsel->fd)
 388                 return -EINVAL;
 389
 390         for (cpu = 0; cpu < nr_cpus; cpu++) {
 391                 err = ioctl(FD(evsel, cpu, thread), PERF_EVENT_IOC_ENABLE, 0);
 392                 if (err)
 393                         return err;
 394         }
 395         return 0;
 396 }
 397
 398 int perf_evlist__enable_event_idx(struct perf_evlist *evlist,
 399                                   struct perf_evsel *evsel, int idx)
 400 {
 401         bool per_cpu_mmaps = !cpu_map__empty(evlist->cpus);
 402
 403         if (per_cpu_mmaps)
 404                 return perf_evlist__enable_event_cpu(evlist, evsel, idx);
 405         else
 406                 return perf_evlist__enable_event_thread(evlist, evsel, idx);
 407 }
 408
 409 int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
 410 {
 411         int nr_cpus = cpu_map__nr(evlist->cpus);
 412         int nr_threads = thread_map__nr(evlist->threads);
 413         int nfds = 0;
 414         struct perf_evsel *evsel;
 415
 416         evlist__for_each(evlist, evsel) {
 417                 if (evsel->system_wide)
 418                         nfds += nr_cpus;
 419                 else
 420                         nfds += nr_cpus * nr_threads;
 421         }
 422
 423         if (fdarray__available_entries(&evlist->pollfd) < nfds &&
 424             fdarray__grow(&evlist->pollfd, nfds) < 0)
 425                 return -ENOMEM;
 426
 427         return 0;
 428 }
 429
 430 static int __perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd, int idx)
 431 {
 432         int pos = fdarray__add(&evlist->pollfd, fd, POLLIN | POLLERR | POLLHUP);
 433         /*
 434          * Save the idx so that when we filter out fds POLLHUP'ed we can
 435          * close the associated evlist->mmap[] entry.
 436          */
 437         if (pos >= 0) {
 438                 evlist->pollfd.priv[pos].idx = idx;
 439
 440                 fcntl(fd, F_SETFL, O_NONBLOCK);
 441         }
 442
 443         return pos;
 444 }
 445
 446 int perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd)
 447 {
 448         return __perf_evlist__add_pollfd(evlist, fd, -1);
 449 }
 450
 451 static void perf_evlist__munmap_filtered(struct fdarray *fda, int fd)
 452 {
 453         struct perf_evlist *evlist = container_of(fda, struct perf_evlist, pollfd);
 454
 455         perf_evlist__mmap_put(evlist, fda->priv[fd].idx);
 456 }
 457
 458 int perf_evlist__filter_pollfd(struct perf_evlist *evlist, short revents_and_mask)
 459 {
 460         return fdarray__filter(&evlist->pollfd, revents_and_mask,
 461                                perf_evlist__munmap_filtered);
 462 }
 463
 464 int perf_evlist__poll(struct perf_evlist *evlist, int timeout)
 465 {
 466         return fdarray__poll(&evlist->pollfd, timeout);
 467 }
 468
 469 static void perf_evlist__id_hash(struct perf_evlist *evlist,
 470                                  struct perf_evsel *evsel,
 471                                  int cpu, int thread, u64 id)
 472 {
 473         int hash;
 474         struct perf_sample_id *sid = SID(evsel, cpu, thread);
 475
 476         sid->id = id;
 477         sid->evsel = evsel;
 478         hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS);
 479         hlist_add_head(&sid->node, &evlist->heads[hash]);
 480 }
 481
 482 void perf_evlist__id_add(struct perf_evlist *evlist, struct perf_evsel *evsel,
 483                          int cpu, int thread, u64 id)
 484 {
 485         perf_evlist__id_hash(evlist, evsel, cpu, thread, id);
 486         evsel->id[evsel->ids++] = id;
 487 }
 488
 489 static int perf_evlist__id_add_fd(struct perf_evlist *evlist,
 490                                   struct perf_evsel *evsel,
 491                                   int cpu, int thread, int fd)
 492 {
 493         u64 read_data[4] = { 0, };
 494         int id_idx = 1; /* The first entry is the counter value */
 495         u64 id;
 496         int ret;
 497
 498         ret = ioctl(fd, PERF_EVENT_IOC_ID, &id);
 499         if (!ret)
 500                 goto add;
 501
 502         if (errno != ENOTTY)
 503                 return -1;
 504
 505         /* Legacy way to get event id.. All hail to old kernels! */
 506
 507         /*
 508          * This way does not work with group format read, so bail
 509          * out in that case.
 510          */
 511         if (perf_evlist__read_format(evlist) & PERF_FORMAT_GROUP)
 512                 return -1;
 513
 514         if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
 515             read(fd, &read_data, sizeof(read_data)) == -1)
 516                 return -1;
 517
 518         if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
 519                 ++id_idx;
 520         if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
 521                 ++id_idx;
 522
 523         id = read_data[id_idx];
 524
 525  add:
 526         perf_evlist__id_add(evlist, evsel, cpu, thread, id);
 527         return 0;
 528 }
 529
 530 static void perf_evlist__set_sid_idx(struct perf_evlist *evlist,
 531                                      struct perf_evsel *evsel, int idx, int cpu,
 532                                      int thread)
 533 {
 534         struct perf_sample_id *sid = SID(evsel, cpu, thread);
 535         sid->idx = idx;
 536         if (evlist->cpus && cpu >= 0)
 537                 sid->cpu = evlist->cpus->map[cpu];
 538         else
 539                 sid->cpu = -1;
 540         if (!evsel->system_wide && evlist->threads && thread >= 0)
 541                 sid->tid = evlist->threads->map[thread];
 542         else
 543                 sid->tid = -1;
 544 }
 545
 546 struct perf_sample_id *perf_evlist__id2sid(struct perf_evlist *evlist, u64 id)
 547 {
 548         struct hlist_head *head;
 549         struct perf_sample_id *sid;
 550         int hash;
 551
 552         hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
 553         head = &evlist->heads[hash];
 554
 555         hlist_for_each_entry(sid, head, node)
 556                 if (sid->id == id)
 557                         return sid;
 558
 559         return NULL;
 560 }
 561
 562 struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id)
 563 {
 564         struct perf_sample_id *sid;
 565
 566         if (evlist->nr_entries == 1)
 567                 return perf_evlist__first(evlist);
 568
 569         sid = perf_evlist__id2sid(evlist, id);
 570         if (sid)
 571                 return sid->evsel;
 572
 573         if (!perf_evlist__sample_id_all(evlist))
 574                 return perf_evlist__first(evlist);
 575
 576         return NULL;
 577 }
 578
 579 static int perf_evlist__event2id(struct perf_evlist *evlist,
 580                                  union perf_event *event, u64 *id)
 581 {
 582         const u64 *array = event->sample.array;
 583         ssize_t n;
 584
 585         n = (event->header.size - sizeof(event->header)) >> 3;
 586
 587         if (event->header.type == PERF_RECORD_SAMPLE) {
 588                 if (evlist->id_pos >= n)
 589                         return -1;
 590                 *id = array[evlist->id_pos];
 591         } else {
 592                 if (evlist->is_pos > n)
 593                         return -1;
 594                 n -= evlist->is_pos;
 595                 *id = array[n];
 596         }
 597         return 0;
 598 }
 599
 600 static struct perf_evsel *perf_evlist__event2evsel(struct perf_evlist *evlist,
 601                                                    union perf_event *event)
 602 {
 603         struct perf_evsel *first = perf_evlist__first(evlist);
 604         struct hlist_head *head;
 605         struct perf_sample_id *sid;
 606         int hash;
 607         u64 id;
 608
 609         if (evlist->nr_entries == 1)
 610                 return first;
 611
 612         if (!first->attr.sample_id_all &&
 613             event->header.type != PERF_RECORD_SAMPLE)
 614                 return first;
 615
 616         if (perf_evlist__event2id(evlist, event, &id))
 617                 return NULL;
 618
 619         /* Synthesized events have an id of zero */
 620         if (!id)
 621                 return first;
 622
 623         hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
 624         head = &evlist->heads[hash];
 625
 626         hlist_for_each_entry(sid, head, node) {
 627                 if (sid->id == id)
 628                         return sid->evsel;
 629         }
 630         return NULL;
 631 }
 632
 633 union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx)
 634 {
 635         struct perf_mmap *md = &evlist->mmap[idx];
 636         unsigned int head = perf_mmap__read_head(md);
 637         unsigned int old = md->prev;
 638         unsigned char *data = md->base + page_size;
 639         union perf_event *event = NULL;
 640
 641         if (evlist->overwrite) {
 642                 /*
 643                  * If we're further behind than half the buffer, there's a chance
 644                  * the writer will bite our tail and mess up the samples under us.
 645                  *
 646                  * If we somehow ended up ahead of the head, we got messed up.
 647                  *
 648                  * In either case, truncate and restart at head.
 649                  */
 650                 int diff = head - old;
 651                 if (diff > md->mask / 2 || diff < 0) {
 652                         fprintf(stderr, "WARNING: failed to keep up with mmap data.\n");
 653
 654                         /*
 655                          * head points to a known good entry, start there.
 656                          */
 657                         old = head;
 658                 }
 659         }
 660
 661         if (old != head) {
 662                 size_t size;
 663
 664                 event = (union perf_event *)&data[old & md->mask];
 665                 size = event->header.size;
 666
 667                 /*
 668                  * Event straddles the mmap boundary -- header should always
 669                  * be inside due to u64 alignment of output.
 670                  */
 671                 if ((old & md->mask) + size != ((old + size) & md->mask)) {
 672                         unsigned int offset = old;
 673                         unsigned int len = min(sizeof(*event), size), cpy;
 674                         void *dst = md->event_copy;
 675
 676                         do {
 677                                 cpy = min(md->mask + 1 - (offset & md->mask), len);
 678                                 memcpy(dst, &data[offset & md->mask], cpy);
 679                                 offset += cpy;
 680                                 dst += cpy;
 681                                 len -= cpy;
 682                         } while (len);
 683
 684                         event = (union perf_event *) md->event_copy;
 685                 }
 686
 687                 old += size;
 688         }
 689
 690         md->prev = old;
 691
 692         return event;
 693 }
 694
 695 static bool perf_mmap__empty(struct perf_mmap *md)
 696 {
 697         return perf_mmap__read_head(md) != md->prev;
 698 }
 699
 700 static void perf_evlist__mmap_get(struct perf_evlist *evlist, int idx)
 701 {
 702         ++evlist->mmap[idx].refcnt;
 703 }
 704
 705 static void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx)
 706 {
 707         BUG_ON(evlist->mmap[idx].refcnt == 0);
 708
 709         if (--evlist->mmap[idx].refcnt == 0)
 710                 __perf_evlist__munmap(evlist, idx);
 711 }
 712
 713 void perf_evlist__mmap_consume(struct perf_evlist *evlist, int idx)
 714 {
 715         struct perf_mmap *md = &evlist->mmap[idx];
 716
 717         if (!evlist->overwrite) {
 718                 unsigned int old = md->prev;
 719
 720                 perf_mmap__write_tail(md, old);
 721         }
 722
 723         if (md->refcnt == 1 && perf_mmap__empty(md))
 724                 perf_evlist__mmap_put(evlist, idx);
 725 }
 726
 727 static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx)
 728 {
 729         if (evlist->mmap[idx].base != NULL) {
 730                 munmap(evlist->mmap[idx].base, evlist->mmap_len);
 731                 evlist->mmap[idx].base = NULL;
 732                 evlist->mmap[idx].refcnt = 0;
 733         }
 734 }
 735
 736 void perf_evlist__munmap(struct perf_evlist *evlist)
 737 {
 738         int i;
 739
 740         if (evlist->mmap == NULL)
 741                 return;
 742
 743         for (i = 0; i < evlist->nr_mmaps; i++)
 744                 __perf_evlist__munmap(evlist, i);
 745
 746         zfree(&evlist->mmap);
 747 }
 748
 749 static int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
 750 {
 751         evlist->nr_mmaps = cpu_map__nr(evlist->cpus);
 752         if (cpu_map__empty(evlist->cpus))
 753                 evlist->nr_mmaps = thread_map__nr(evlist->threads);
 754         evlist->mmap = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap));
 755         return evlist->mmap != NULL ? 0 : -ENOMEM;
 756 }
 757
 758 struct mmap_params {
 759         int prot;
 760         int mask;
 761 };
 762
 763 static int __perf_evlist__mmap(struct perf_evlist *evlist, int idx,
 764                                struct mmap_params *mp, int fd)
 765 {
 766         /*
 767          * The last one will be done at perf_evlist__mmap_consume(), so that we
 768          * make sure we don't prevent tools from consuming every last event in
 769          * the ring buffer.
 770          *
 771          * I.e. we can get the POLLHUP meaning that the fd doesn't exist
 772          * anymore, but the last events for it are still in the ring buffer,
 773          * waiting to be consumed.
 774          *
 775          * Tools can chose to ignore this at their own discretion, but the
 776          * evlist layer can't just drop it when filtering events in
 777          * perf_evlist__filter_pollfd().
 778          */
 779         evlist->mmap[idx].refcnt = 2;
 780         evlist->mmap[idx].prev = 0;
 781         evlist->mmap[idx].mask = mp->mask;
 782         evlist->mmap[idx].base = mmap(NULL, evlist->mmap_len, mp->prot,
 783                                       MAP_SHARED, fd, 0);
 784         if (evlist->mmap[idx].base == MAP_FAILED) {
 785                 pr_debug2("failed to mmap perf event ring buffer, error %d\n",
 786                           errno);
 787                 evlist->mmap[idx].base = NULL;
 788                 return -1;
 789         }
 790
 791         return 0;
 792 }
 793
 794 static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int idx,
 795                                        struct mmap_params *mp, int cpu,
 796                                        int thread, int *output)
 797 {
 798         struct perf_evsel *evsel;
 799
 800         evlist__for_each(evlist, evsel) {
 801                 int fd;
 802
 803                 if (evsel->system_wide && thread)
 804                         continue;
 805
 806                 fd = FD(evsel, cpu, thread);
 807
 808                 if (*output == -1) {
 809                         *output = fd;
 810                         if (__perf_evlist__mmap(evlist, idx, mp, *output) < 0)
 811                                 return -1;
 812                 } else {
 813                         if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0)
 814                                 return -1;
 815
 816                         perf_evlist__mmap_get(evlist, idx);
 817                 }
 818
 819                 /*
 820                  * The system_wide flag causes a selected event to be opened
 821                  * always without a pid.  Consequently it will never get a
 822                  * POLLHUP, but it is used for tracking in combination with
 823                  * other events, so it should not need to be polled anyway.
 824                  * Therefore don't add it for polling.
 825                  */
 826                 if (!evsel->system_wide &&
 827                     __perf_evlist__add_pollfd(evlist, fd, idx) < 0) {
 828                         perf_evlist__mmap_put(evlist, idx);
 829                         return -1;
 830                 }
 831
 832                 if (evsel->attr.read_format & PERF_FORMAT_ID) {
 833                         if (perf_evlist__id_add_fd(evlist, evsel, cpu, thread,
 834                                                    fd) < 0)
 835                                 return -1;
 836                         perf_evlist__set_sid_idx(evlist, evsel, idx, cpu,
 837                                                  thread);
 838                 }
 839         }
 840
 841         return 0;
 842 }
 843
 844 static int perf_evlist__mmap_per_cpu(struct perf_evlist *evlist,
 845                                      struct mmap_params *mp)
 846 {
 847         int cpu, thread;
 848         int nr_cpus = cpu_map__nr(evlist->cpus);
 849         int nr_threads = thread_map__nr(evlist->threads);
 850
 851         pr_debug2("perf event ring buffer mmapped per cpu\n");
 852         for (cpu = 0; cpu < nr_cpus; cpu++) {
 853                 int output = -1;
 854
 855                 for (thread = 0; thread < nr_threads; thread++) {
 856                         if (perf_evlist__mmap_per_evsel(evlist, cpu, mp, cpu,
 857                                                         thread, &output))
 858                                 goto out_unmap;
 859                 }
 860         }
 861
 862         return 0;
 863
 864 out_unmap:
 865         for (cpu = 0; cpu < nr_cpus; cpu++)
 866                 __perf_evlist__munmap(evlist, cpu);
 867         return -1;
 868 }
 869
 870 static int perf_evlist__mmap_per_thread(struct perf_evlist *evlist,
 871                                         struct mmap_params *mp)
 872 {
 873         int thread;
 874         int nr_threads = thread_map__nr(evlist->threads);
 875
 876         pr_debug2("perf event ring buffer mmapped per thread\n");
 877         for (thread = 0; thread < nr_threads; thread++) {
 878                 int output = -1;
 879
 880                 if (perf_evlist__mmap_per_evsel(evlist, thread, mp, 0, thread,
 881                                                 &output))
 882                         goto out_unmap;
 883         }
 884
 885         return 0;
 886
 887 out_unmap:
 888         for (thread = 0; thread < nr_threads; thread++)
 889                 __perf_evlist__munmap(evlist, thread);
 890         return -1;
 891 }
 892
 893 static size_t perf_evlist__mmap_size(unsigned long pages)
 894 {
 895         /* 512 kiB: default amount of unprivileged mlocked memory */
 896         if (pages == UINT_MAX)
 897                 pages = (512 * 1024) / page_size;
 898         else if (!is_power_of_2(pages))
 899                 return 0;
 900
 901         return (pages + 1) * page_size;
 902 }
 903
 904 static long parse_pages_arg(const char *str, unsigned long min,
 905                             unsigned long max)
 906 {
 907         unsigned long pages, val;
 908         static struct parse_tag tags[] = {
 909                 { .tag  = 'B', .mult = 1       },
 910                 { .tag  = 'K', .mult = 1 << 10 },
 911                 { .tag  = 'M', .mult = 1 << 20 },
 912                 { .tag  = 'G', .mult = 1 << 30 },
 913                 { .tag  = 0 },
 914         };
 915
 916         if (str == NULL)
 917                 return -EINVAL;
 918
 919         val = parse_tag_value(str, tags);
 920         if (val != (unsigned long) -1) {
 921                 /* we got file size value */
 922                 pages = PERF_ALIGN(val, page_size) / page_size;
 923         } else {
 924                 /* we got pages count value */
 925                 char *eptr;
 926                 pages = strtoul(str, &eptr, 10);
 927                 if (*eptr != '\0')
 928                         return -EINVAL;
 929         }
 930
 931         if (pages == 0 && min == 0) {
 932                 /* leave number of pages at 0 */
 933         } else if (!is_power_of_2(pages)) {
 934                 /* round pages up to next power of 2 */
 935                 pages = next_pow2_l(pages);
 936                 if (!pages)
 937                         return -EINVAL;
 938                 pr_info("rounding mmap pages size to %lu bytes (%lu pages)\n",
 939                         pages * page_size, pages);
 940         }
 941
 942         if (pages > max)
 943                 return -EINVAL;
 944
 945         return pages;
 946 }
 947
 948 int perf_evlist__parse_mmap_pages(const struct option *opt, const char *str,
 949                                   int unset __maybe_unused)
 950 {
 951         unsigned int *mmap_pages = opt->value;
 952         unsigned long max = UINT_MAX;
 953         long pages;
 954
 955         if (max > SIZE_MAX / page_size)
 956                 max = SIZE_MAX / page_size;
 957
 958         pages = parse_pages_arg(str, 1, max);
 959         if (pages < 0) {
 960                 pr_err("Invalid argument for --mmap_pages/-m\n");
 961                 return -1;
 962         }
 963
 964         *mmap_pages = pages;
 965         return 0;
 966 }
 967
 968 /**
 969  * perf_evlist__mmap - Create mmaps to receive events.
 970  * @evlist: list of events
 971  * @pages: map length in pages
 972  * @overwrite: overwrite older events?
 973  *
 974  * If @overwrite is %false the user needs to signal event consumption using
 975  * perf_mmap__write_tail().  Using perf_evlist__mmap_read() does this
 976  * automatically.
 977  *
 978  * Return: %0 on success, negative error code otherwise.
 979  */
 980 int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
 981                       bool overwrite)
 982 {
 983         struct perf_evsel *evsel;
 984         const struct cpu_map *cpus = evlist->cpus;
 985         const struct thread_map *threads = evlist->threads;
 986         struct mmap_params mp = {
 987                 .prot = PROT_READ | (overwrite ? 0 : PROT_WRITE),
 988         };
 989
 990         if (evlist->mmap == NULL && perf_evlist__alloc_mmap(evlist) < 0)
 991                 return -ENOMEM;
 992
 993         if (evlist->pollfd.entries == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
 994                 return -ENOMEM;
 995
 996         evlist->overwrite = overwrite;
 997         evlist->mmap_len = perf_evlist__mmap_size(pages);
 998         pr_debug("mmap size %zuB\n", evlist->mmap_len);
 999         mp.mask = evlist->mmap_len - page_size - 1;
1000
1001         evlist__for_each(evlist, evsel) {
1002                 if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
1003                     evsel->sample_id == NULL &&
1004                     perf_evsel__alloc_id(evsel, cpu_map__nr(cpus), threads->nr) < 0)
1005                         return -ENOMEM;
1006         }
1007
1008         if (cpu_map__empty(cpus))
1009                 return perf_evlist__mmap_per_thread(evlist, &mp);
1010
1011         return perf_evlist__mmap_per_cpu(evlist, &mp);
1012 }
1013
1014 int perf_evlist__create_maps(struct perf_evlist *evlist, struct target *target)
1015 {
1016         evlist->threads = thread_map__new_str(target->pid, target->tid,
1017                                               target->uid);
1018
1019         if (evlist->threads == NULL)
1020                 return -1;
1021
1022         if (target__uses_dummy_map(target))
1023                 evlist->cpus = cpu_map__dummy_new();
1024         else
1025                 evlist->cpus = cpu_map__new(target->cpu_list);
1026
1027         if (evlist->cpus == NULL)
1028                 goto out_delete_threads;
1029
1030         return 0;
1031
1032 out_delete_threads:
1033         thread_map__delete(evlist->threads);
1034         evlist->threads = NULL;
1035         return -1;
1036 }
1037
1038 int perf_evlist__apply_filters(struct perf_evlist *evlist)
1039 {
1040         struct perf_evsel *evsel;
1041         int err = 0;
1042         const int ncpus = cpu_map__nr(evlist->cpus),
1043                   nthreads = thread_map__nr(evlist->threads);
1044
1045         evlist__for_each(evlist, evsel) {
1046                 if (evsel->filter == NULL)
1047                         continue;
1048
1049                 err = perf_evsel__set_filter(evsel, ncpus, nthreads, evsel->filter);
1050                 if (err)
1051                         break;
1052         }
1053
1054         return err;
1055 }
1056
1057 int perf_evlist__set_filter(struct perf_evlist *evlist, const char *filter)
1058 {
1059         struct perf_evsel *evsel;
1060         int err = 0;
1061         const int ncpus = cpu_map__nr(evlist->cpus),
1062                   nthreads = thread_map__nr(evlist->threads);
1063
1064         evlist__for_each(evlist, evsel) {
1065                 err = perf_evsel__set_filter(evsel, ncpus, nthreads, filter);
1066                 if (err)
1067                         break;
1068         }
1069
1070         return err;
1071 }
1072
1073 bool perf_evlist__valid_sample_type(struct perf_evlist *evlist)
1074 {
1075         struct perf_evsel *pos;
1076
1077         if (evlist->nr_entries == 1)
1078                 return true;
1079
1080         if (evlist->id_pos < 0 || evlist->is_pos < 0)
1081                 return false;
1082
1083         evlist__for_each(evlist, pos) {
1084                 if (pos->id_pos != evlist->id_pos ||
1085                     pos->is_pos != evlist->is_pos)
1086                         return false;
1087         }
1088
1089         return true;
1090 }
1091
1092 u64 __perf_evlist__combined_sample_type(struct perf_evlist *evlist)
1093 {
1094         struct perf_evsel *evsel;
1095
1096         if (evlist->combined_sample_type)
1097                 return evlist->combined_sample_type;
1098
1099         evlist__for_each(evlist, evsel)
1100                 evlist->combined_sample_type |= evsel->attr.sample_type;
1101
1102         return evlist->combined_sample_type;
1103 }
1104
1105 u64 perf_evlist__combined_sample_type(struct perf_evlist *evlist)
1106 {
1107         evlist->combined_sample_type = 0;
1108         return __perf_evlist__combined_sample_type(evlist);
1109 }
1110
1111 bool perf_evlist__valid_read_format(struct perf_evlist *evlist)
1112 {
1113         struct perf_evsel *first = perf_evlist__first(evlist), *pos = first;
1114         u64 read_format = first->attr.read_format;
1115         u64 sample_type = first->attr.sample_type;
1116
1117         evlist__for_each(evlist, pos) {
1118                 if (read_format != pos->attr.read_format)
1119                         return false;
1120         }
1121
1122         /* PERF_SAMPLE_READ imples PERF_FORMAT_ID. */
1123         if ((sample_type & PERF_SAMPLE_READ) &&
1124             !(read_format & PERF_FORMAT_ID)) {
1125                 return false;
1126         }
1127
1128         return true;
1129 }
1130
1131 u64 perf_evlist__read_format(struct perf_evlist *evlist)
1132 {
1133         struct perf_evsel *first = perf_evlist__first(evlist);
1134         return first->attr.read_format;
1135 }
1136
1137 u16 perf_evlist__id_hdr_size(struct perf_evlist *evlist)
1138 {
1139         struct perf_evsel *first = perf_evlist__first(evlist);
1140         struct perf_sample *data;
1141         u64 sample_type;
1142         u16 size = 0;
1143
1144         if (!first->attr.sample_id_all)
1145                 goto out;
1146
1147         sample_type = first->attr.sample_type;
1148
1149         if (sample_type & PERF_SAMPLE_TID)
1150                 size += sizeof(data->tid) * 2;
1151
1152        if (sample_type & PERF_SAMPLE_TIME)
1153                 size += sizeof(data->time);
1154
1155         if (sample_type & PERF_SAMPLE_ID)
1156                 size += sizeof(data->id);
1157
1158         if (sample_type & PERF_SAMPLE_STREAM_ID)
1159                 size += sizeof(data->stream_id);
1160
1161         if (sample_type & PERF_SAMPLE_CPU)
1162                 size += sizeof(data->cpu) * 2;
1163
1164         if (sample_type & PERF_SAMPLE_IDENTIFIER)
1165                 size += sizeof(data->id);
1166 out:
1167         return size;
1168 }
1169
1170 bool perf_evlist__valid_sample_id_all(struct perf_evlist *evlist)
1171 {
1172         struct perf_evsel *first = perf_evlist__first(evlist), *pos = first;
1173
1174         evlist__for_each_continue(evlist, pos) {
1175                 if (first->attr.sample_id_all != pos->attr.sample_id_all)
1176                         return false;
1177         }
1178
1179         return true;
1180 }
1181
1182 bool perf_evlist__sample_id_all(struct perf_evlist *evlist)
1183 {
1184         struct perf_evsel *first = perf_evlist__first(evlist);
1185         return first->attr.sample_id_all;
1186 }
1187
1188 void perf_evlist__set_selected(struct perf_evlist *evlist,
1189                                struct perf_evsel *evsel)
1190 {
1191         evlist->selected = evsel;
1192 }
1193
1194 void perf_evlist__close(struct perf_evlist *evlist)
1195 {
1196         struct perf_evsel *evsel;
1197         int ncpus = cpu_map__nr(evlist->cpus);
1198         int nthreads = thread_map__nr(evlist->threads);
1199         int n;
1200
1201         evlist__for_each_reverse(evlist, evsel) {
1202                 n = evsel->cpus ? evsel->cpus->nr : ncpus;
1203                 perf_evsel__close(evsel, n, nthreads);
1204         }
1205 }
1206
1207 static int perf_evlist__create_syswide_maps(struct perf_evlist *evlist)
1208 {
1209         int err = -ENOMEM;
1210
1211         /*
1212          * Try reading /sys/devices/system/cpu/online to get
1213          * an all cpus map.
1214          *
1215          * FIXME: -ENOMEM is the best we can do here, the cpu_map
1216          * code needs an overhaul to properly forward the
1217          * error, and we may not want to do that fallback to a
1218          * default cpu identity map :-\
1219          */
1220         evlist->cpus = cpu_map__new(NULL);
1221         if (evlist->cpus == NULL)
1222                 goto out;
1223
1224         evlist->threads = thread_map__new_dummy();
1225         if (evlist->threads == NULL)
1226                 goto out_free_cpus;
1227
1228         err = 0;
1229 out:
1230         return err;
1231 out_free_cpus:
1232         cpu_map__delete(evlist->cpus);
1233         evlist->cpus = NULL;
1234         goto out;
1235 }
1236
1237 int perf_evlist__open(struct perf_evlist *evlist)
1238 {
1239         struct perf_evsel *evsel;
1240         int err;
1241
1242         /*
1243          * Default: one fd per CPU, all threads, aka systemwide
1244          * as sys_perf_event_open(cpu = -1, thread = -1) is EINVAL
1245          */
1246         if (evlist->threads == NULL && evlist->cpus == NULL) {
1247                 err = perf_evlist__create_syswide_maps(evlist);
1248                 if (err < 0)
1249                         goto out_err;
1250         }
1251
1252         perf_evlist__update_id_pos(evlist);
1253
1254         evlist__for_each(evlist, evsel) {
1255                 err = perf_evsel__open(evsel, evlist->cpus, evlist->threads);
1256                 if (err < 0)
1257                         goto out_err;
1258         }
1259
1260         return 0;
1261 out_err:
1262         perf_evlist__close(evlist);
1263         errno = -err;
1264         return err;
1265 }
1266
1267 int perf_evlist__prepare_workload(struct perf_evlist *evlist, struct target *target,
1268                                   const char *argv[], bool pipe_output,
1269                                   void (*exec_error)(int signo, siginfo_t *info, void *ucontext))
1270 {
1271         int child_ready_pipe[2], go_pipe[2];
1272         char bf;
1273
1274         if (pipe(child_ready_pipe) < 0) {
1275                 perror("failed to create 'ready' pipe");
1276                 return -1;
1277         }
1278
1279         if (pipe(go_pipe) < 0) {
1280                 perror("failed to create 'go' pipe");
1281                 goto out_close_ready_pipe;
1282         }
1283
1284         evlist->workload.pid = fork();
1285         if (evlist->workload.pid < 0) {
1286                 perror("failed to fork");
1287                 goto out_close_pipes;
1288         }
1289
1290         if (!evlist->workload.pid) {
1291                 int ret;
1292
1293                 if (pipe_output)
1294                         dup2(2, 1);
1295
1296                 signal(SIGTERM, SIG_DFL);
1297
1298                 close(child_ready_pipe[0]);
1299                 close(go_pipe[1]);
1300                 fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
1301
1302                 /*
1303                  * Tell the parent we're ready to go
1304                  */
1305                 close(child_ready_pipe[1]);
1306
1307                 /*
1308                  * Wait until the parent tells us to go.
1309                  */
1310                 ret = read(go_pipe[0], &bf, 1);
1311                 /*
1312                  * The parent will ask for the execvp() to be performed by
1313                  * writing exactly one byte, in workload.cork_fd, usually via
1314                  * perf_evlist__start_workload().
1315                  *
1316                  * For cancelling the workload without actuallin running it,
1317                  * the parent will just close workload.cork_fd, without writing
1318                  * anything, i.e. read will return zero and we just exit()
1319                  * here.
1320                  */
1321                 if (ret != 1) {
1322                         if (ret == -1)
1323                                 perror("unable to read pipe");
1324                         exit(ret);
1325                 }
1326
1327                 execvp(argv[0], (char **)argv);
1328
1329                 if (exec_error) {
1330                         union sigval val;
1331
1332                         val.sival_int = errno;
1333                         if (sigqueue(getppid(), SIGUSR1, val))
1334                                 perror(argv[0]);
1335                 } else
1336                         perror(argv[0]);
1337                 exit(-1);
1338         }
1339
1340         if (exec_error) {
1341                 struct sigaction act = {
1342                         .sa_flags     = SA_SIGINFO,
1343                         .sa_sigaction = exec_error,
1344                 };
1345                 sigaction(SIGUSR1, &act, NULL);
1346         }
1347
1348         if (target__none(target)) {
1349                 if (evlist->threads == NULL) {
1350                         fprintf(stderr, "FATAL: evlist->threads need to be set at this point (%s:%d).\n",
1351                                 __func__, __LINE__);
1352                         goto out_close_pipes;
1353                 }
1354                 evlist->threads->map[0] = evlist->workload.pid;
1355         }
1356
1357         close(child_ready_pipe[1]);
1358         close(go_pipe[0]);
1359         /*
1360          * wait for child to settle
1361          */
1362         if (read(child_ready_pipe[0], &bf, 1) == -1) {
1363                 perror("unable to read pipe");
1364                 goto out_close_pipes;
1365         }
1366
1367         fcntl(go_pipe[1], F_SETFD, FD_CLOEXEC);
1368         evlist->workload.cork_fd = go_pipe[1];
1369         close(child_ready_pipe[0]);
1370         return 0;
1371
1372 out_close_pipes:
1373         close(go_pipe[0]);
1374         close(go_pipe[1]);
1375 out_close_ready_pipe:
1376         close(child_ready_pipe[0]);
1377         close(child_ready_pipe[1]);
1378         return -1;
1379 }
1380
1381 int perf_evlist__start_workload(struct perf_evlist *evlist)
1382 {
1383         if (evlist->workload.cork_fd > 0) {
1384                 char bf = 0;
1385                 int ret;
1386                 /*
1387                  * Remove the cork, let it rip!
1388                  */
1389                 ret = write(evlist->workload.cork_fd, &bf, 1);
1390                 if (ret < 0)
1391                         perror("enable to write to pipe");
1392
1393                 close(evlist->workload.cork_fd);
1394                 return ret;
1395         }
1396
1397         return 0;
1398 }
1399
1400 int perf_evlist__parse_sample(struct perf_evlist *evlist, union perf_event *event,
1401                               struct perf_sample *sample)
1402 {
1403         struct perf_evsel *evsel = perf_evlist__event2evsel(evlist, event);
1404
1405         if (!evsel)
1406                 return -EFAULT;
1407         return perf_evsel__parse_sample(evsel, event, sample);
1408 }
1409
1410 size_t perf_evlist__fprintf(struct perf_evlist *evlist, FILE *fp)
1411 {
1412         struct perf_evsel *evsel;
1413         size_t printed = 0;
1414
1415         evlist__for_each(evlist, evsel) {
1416                 printed += fprintf(fp, "%s%s", evsel->idx ? ", " : "",
1417                                    perf_evsel__name(evsel));
1418         }
1419
1420         return printed + fprintf(fp, "\n");
1421 }
1422
1423 int perf_evlist__strerror_tp(struct perf_evlist *evlist __maybe_unused,
1424                              int err, char *buf, size_t size)
1425 {
1426         char sbuf[128];
1427
1428         switch (err) {
1429         case ENOENT:
1430                 scnprintf(buf, size, "%s",
1431                           "Error:\tUnable to find debugfs\n"
1432                           "Hint:\tWas your kernel was compiled with debugfs support?\n"
1433                           "Hint:\tIs the debugfs filesystem mounted?\n"
1434                           "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'");
1435                 break;
1436         case EACCES:
1437                 scnprintf(buf, size,
1438                           "Error:\tNo permissions to read %s/tracing/events/raw_syscalls\n"
1439                           "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",
1440                           debugfs_mountpoint, debugfs_mountpoint);
1441                 break;
1442         default:
1443                 scnprintf(buf, size, "%s", strerror_r(err, sbuf, sizeof(sbuf)));
1444                 break;
1445         }
1446
1447         return 0;
1448 }
1449
1450 int perf_evlist__strerror_open(struct perf_evlist *evlist __maybe_unused,
1451                                int err, char *buf, size_t size)
1452 {
1453         int printed, value;
1454         char sbuf[STRERR_BUFSIZE], *emsg = strerror_r(err, sbuf, sizeof(sbuf));
1455
1456         switch (err) {
1457         case EACCES:
1458         case EPERM:
1459                 printed = scnprintf(buf, size,
1460                                     "Error:\t%s.\n"
1461                                     "Hint:\tCheck /proc/sys/kernel/perf_event_paranoid setting.", emsg);
1462
1463                 value = perf_event_paranoid();
1464
1465                 printed += scnprintf(buf + printed, size - printed, "\nHint:\t");
1466
1467                 if (value >= 2) {
1468                         printed += scnprintf(buf + printed, size - printed,
1469                                              "For your workloads it needs to be <= 1\nHint:\t");
1470                 }
1471                 printed += scnprintf(buf + printed, size - printed,
1472                                      "For system wide tracing it needs to be set to -1.\n");
1473
1474                 printed += scnprintf(buf + printed, size - printed,
1475                                     "Hint:\tTry: 'sudo sh -c \"echo -1 > /proc/sys/kernel/perf_event_paranoid\"'\n"
1476                                     "Hint:\tThe current value is %d.", value);
1477                 break;
1478         default:
1479                 scnprintf(buf, size, "%s", emsg);
1480                 break;
1481         }
1482
1483         return 0;
1484 }
1485
1486 void perf_evlist__to_front(struct perf_evlist *evlist,
1487                            struct perf_evsel *move_evsel)
1488 {
1489         struct perf_evsel *evsel, *n;
1490         LIST_HEAD(move);
1491
1492         if (move_evsel == perf_evlist__first(evlist))
1493                 return;
1494
1495         evlist__for_each_safe(evlist, n, evsel) {
1496                 if (evsel->leader == move_evsel->leader)
1497                         list_move_tail(&evsel->node, &move);
1498         }
1499
1500         list_splice(&move, &evlist->entries);
1501 }
1502
1503 void perf_evlist__set_tracking_event(struct perf_evlist *evlist,
1504                                      struct perf_evsel *tracking_evsel)
1505 {
1506         struct perf_evsel *evsel;
1507
1508         if (tracking_evsel->tracking)
1509                 return;
1510
1511         evlist__for_each(evlist, evsel) {
1512                 if (evsel != tracking_evsel)
1513                         evsel->tracking = false;
1514         }
1515
1516         tracking_evsel->tracking = true;
1517 }