tools/lib/perf/evlist.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <perf/evlist.h>
   3 #include <perf/evsel.h>
   4 #include <linux/bitops.h>
   5 #include <linux/list.h>
   6 #include <linux/hash.h>
   7 #include <sys/ioctl.h>
   8 #include <internal/evlist.h>
   9 #include <internal/evsel.h>
  10 #include <internal/xyarray.h>
  11 #include <internal/mmap.h>
  12 #include <internal/cpumap.h>
  13 #include <internal/threadmap.h>
  14 #include <internal/xyarray.h>
  15 #include <internal/lib.h>
  16 #include <linux/zalloc.h>
  17 #include <sys/ioctl.h>
  18 #include <stdlib.h>
  19 #include <errno.h>
  20 #include <unistd.h>
  21 #include <fcntl.h>
  22 #include <signal.h>
  23 #include <poll.h>
  24 #include <sys/mman.h>
  25 #include <perf/cpumap.h>
  26 #include <perf/threadmap.h>
  27 #include <api/fd/array.h>
  28
  29 void perf_evlist__init(struct perf_evlist *evlist)
  30 {
  31         int i;
  32
  33         for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
  34                 INIT_HLIST_HEAD(&evlist->heads[i]);
  35         INIT_LIST_HEAD(&evlist->entries);
  36         evlist->nr_entries = 0;
  37         fdarray__init(&evlist->pollfd, 64);
  38 }
  39
  40 static void __perf_evlist__propagate_maps(struct perf_evlist *evlist,
  41                                           struct perf_evsel *evsel)
  42 {
  43         /*
  44          * We already have cpus for evsel (via PMU sysfs) so
  45          * keep it, if there's no target cpu list defined.
  46          */
  47         if (!evsel->own_cpus || evlist->has_user_cpus) {
  48                 perf_cpu_map__put(evsel->cpus);
  49                 evsel->cpus = perf_cpu_map__get(evlist->cpus);
  50         } else if (evsel->cpus != evsel->own_cpus) {
  51                 perf_cpu_map__put(evsel->cpus);
  52                 evsel->cpus = perf_cpu_map__get(evsel->own_cpus);
  53         }
  54
  55         perf_thread_map__put(evsel->threads);
  56         evsel->threads = perf_thread_map__get(evlist->threads);
  57         evlist->all_cpus = perf_cpu_map__merge(evlist->all_cpus, evsel->cpus);
  58 }
  59
  60 static void perf_evlist__propagate_maps(struct perf_evlist *evlist)
  61 {
  62         struct perf_evsel *evsel;
  63
  64         perf_evlist__for_each_evsel(evlist, evsel)
  65                 __perf_evlist__propagate_maps(evlist, evsel);
  66 }
  67
  68 void perf_evlist__add(struct perf_evlist *evlist,
  69                       struct perf_evsel *evsel)
  70 {
  71         list_add_tail(&evsel->node, &evlist->entries);
  72         evlist->nr_entries += 1;
  73         __perf_evlist__propagate_maps(evlist, evsel);
  74 }
  75
  76 void perf_evlist__remove(struct perf_evlist *evlist,
  77                          struct perf_evsel *evsel)
  78 {
  79         list_del_init(&evsel->node);
  80         evlist->nr_entries -= 1;
  81 }
  82
  83 struct perf_evlist *perf_evlist__new(void)
  84 {
  85         struct perf_evlist *evlist = zalloc(sizeof(*evlist));
  86
  87         if (evlist != NULL)
  88                 perf_evlist__init(evlist);
  89
  90         return evlist;
  91 }
  92
  93 struct perf_evsel *
  94 perf_evlist__next(struct perf_evlist *evlist, struct perf_evsel *prev)
  95 {
  96         struct perf_evsel *next;
  97
  98         if (!prev) {
  99                 next = list_first_entry(&evlist->entries,
 100                                         struct perf_evsel,
 101                                         node);
 102         } else {
 103                 next = list_next_entry(prev, node);
 104         }
 105
 106         /* Empty list is noticed here so don't need checking on entry. */
 107         if (&next->node == &evlist->entries)
 108                 return NULL;
 109
 110         return next;
 111 }
 112
 113 static void perf_evlist__purge(struct perf_evlist *evlist)
 114 {
 115         struct perf_evsel *pos, *n;
 116
 117         perf_evlist__for_each_entry_safe(evlist, n, pos) {
 118                 list_del_init(&pos->node);
 119                 perf_evsel__delete(pos);
 120         }
 121
 122         evlist->nr_entries = 0;
 123 }
 124
 125 void perf_evlist__exit(struct perf_evlist *evlist)
 126 {
 127         perf_cpu_map__put(evlist->cpus);
 128         perf_thread_map__put(evlist->threads);
 129         evlist->cpus = NULL;
 130         evlist->threads = NULL;
 131         fdarray__exit(&evlist->pollfd);
 132 }
 133
 134 void perf_evlist__delete(struct perf_evlist *evlist)
 135 {
 136         if (evlist == NULL)
 137                 return;
 138
 139         perf_evlist__munmap(evlist);
 140         perf_evlist__close(evlist);
 141         perf_evlist__purge(evlist);
 142         perf_evlist__exit(evlist);
 143         free(evlist);
 144 }
 145
 146 void perf_evlist__set_maps(struct perf_evlist *evlist,
 147                            struct perf_cpu_map *cpus,
 148                            struct perf_thread_map *threads)
 149 {
 150         /*
 151          * Allow for the possibility that one or another of the maps isn't being
 152          * changed i.e. don't put it.  Note we are assuming the maps that are
 153          * being applied are brand new and evlist is taking ownership of the
 154          * original reference count of 1.  If that is not the case it is up to
 155          * the caller to increase the reference count.
 156          */
 157         if (cpus != evlist->cpus) {
 158                 perf_cpu_map__put(evlist->cpus);
 159                 evlist->cpus = perf_cpu_map__get(cpus);
 160         }
 161
 162         if (threads != evlist->threads) {
 163                 perf_thread_map__put(evlist->threads);
 164                 evlist->threads = perf_thread_map__get(threads);
 165         }
 166
 167         if (!evlist->all_cpus && cpus)
 168                 evlist->all_cpus = perf_cpu_map__get(cpus);
 169
 170         perf_evlist__propagate_maps(evlist);
 171 }
 172
 173 int perf_evlist__open(struct perf_evlist *evlist)
 174 {
 175         struct perf_evsel *evsel;
 176         int err;
 177
 178         perf_evlist__for_each_entry(evlist, evsel) {
 179                 err = perf_evsel__open(evsel, evsel->cpus, evsel->threads);
 180                 if (err < 0)
 181                         goto out_err;
 182         }
 183
 184         return 0;
 185
 186 out_err:
 187         perf_evlist__close(evlist);
 188         return err;
 189 }
 190
 191 void perf_evlist__close(struct perf_evlist *evlist)
 192 {
 193         struct perf_evsel *evsel;
 194
 195         perf_evlist__for_each_entry_reverse(evlist, evsel)
 196                 perf_evsel__close(evsel);
 197 }
 198
 199 void perf_evlist__enable(struct perf_evlist *evlist)
 200 {
 201         struct perf_evsel *evsel;
 202
 203         perf_evlist__for_each_entry(evlist, evsel)
 204                 perf_evsel__enable(evsel);
 205 }
 206
 207 void perf_evlist__disable(struct perf_evlist *evlist)
 208 {
 209         struct perf_evsel *evsel;
 210
 211         perf_evlist__for_each_entry(evlist, evsel)
 212                 perf_evsel__disable(evsel);
 213 }
 214
 215 u64 perf_evlist__read_format(struct perf_evlist *evlist)
 216 {
 217         struct perf_evsel *first = perf_evlist__first(evlist);
 218
 219         return first->attr.read_format;
 220 }
 221
 222 #define SID(e, x, y) xyarray__entry(e->sample_id, x, y)
 223
 224 static void perf_evlist__id_hash(struct perf_evlist *evlist,
 225                                  struct perf_evsel *evsel,
 226                                  int cpu, int thread, u64 id)
 227 {
 228         int hash;
 229         struct perf_sample_id *sid = SID(evsel, cpu, thread);
 230
 231         sid->id = id;
 232         sid->evsel = evsel;
 233         hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS);
 234         hlist_add_head(&sid->node, &evlist->heads[hash]);
 235 }
 236
 237 void perf_evlist__id_add(struct perf_evlist *evlist,
 238                          struct perf_evsel *evsel,
 239                          int cpu, int thread, u64 id)
 240 {
 241         perf_evlist__id_hash(evlist, evsel, cpu, thread, id);
 242         evsel->id[evsel->ids++] = id;
 243 }
 244
 245 int perf_evlist__id_add_fd(struct perf_evlist *evlist,
 246                            struct perf_evsel *evsel,
 247                            int cpu, int thread, int fd)
 248 {
 249         u64 read_data[4] = { 0, };
 250         int id_idx = 1; /* The first entry is the counter value */
 251         u64 id;
 252         int ret;
 253
 254         ret = ioctl(fd, PERF_EVENT_IOC_ID, &id);
 255         if (!ret)
 256                 goto add;
 257
 258         if (errno != ENOTTY)
 259                 return -1;
 260
 261         /* Legacy way to get event id.. All hail to old kernels! */
 262
 263         /*
 264          * This way does not work with group format read, so bail
 265          * out in that case.
 266          */
 267         if (perf_evlist__read_format(evlist) & PERF_FORMAT_GROUP)
 268                 return -1;
 269
 270         if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
 271             read(fd, &read_data, sizeof(read_data)) == -1)
 272                 return -1;
 273
 274         if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
 275                 ++id_idx;
 276         if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
 277                 ++id_idx;
 278
 279         id = read_data[id_idx];
 280
 281 add:
 282         perf_evlist__id_add(evlist, evsel, cpu, thread, id);
 283         return 0;
 284 }
 285
 286 int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
 287 {
 288         int nr_cpus = perf_cpu_map__nr(evlist->cpus);
 289         int nr_threads = perf_thread_map__nr(evlist->threads);
 290         int nfds = 0;
 291         struct perf_evsel *evsel;
 292
 293         perf_evlist__for_each_entry(evlist, evsel) {
 294                 if (evsel->system_wide)
 295                         nfds += nr_cpus;
 296                 else
 297                         nfds += nr_cpus * nr_threads;
 298         }
 299
 300         if (fdarray__available_entries(&evlist->pollfd) < nfds &&
 301             fdarray__grow(&evlist->pollfd, nfds) < 0)
 302                 return -ENOMEM;
 303
 304         return 0;
 305 }
 306
 307 int perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd,
 308                             void *ptr, short revent)
 309 {
 310         int pos = fdarray__add(&evlist->pollfd, fd, revent | POLLERR | POLLHUP);
 311
 312         if (pos >= 0) {
 313                 evlist->pollfd.priv[pos].ptr = ptr;
 314                 fcntl(fd, F_SETFL, O_NONBLOCK);
 315         }
 316
 317         return pos;
 318 }
 319
 320 static void perf_evlist__munmap_filtered(struct fdarray *fda, int fd,
 321                                          void *arg __maybe_unused)
 322 {
 323         struct perf_mmap *map = fda->priv[fd].ptr;
 324
 325         if (map)
 326                 perf_mmap__put(map);
 327 }
 328
 329 int perf_evlist__filter_pollfd(struct perf_evlist *evlist, short revents_and_mask)
 330 {
 331         return fdarray__filter(&evlist->pollfd, revents_and_mask,
 332                                perf_evlist__munmap_filtered, NULL);
 333 }
 334
 335 int perf_evlist__poll(struct perf_evlist *evlist, int timeout)
 336 {
 337         return fdarray__poll(&evlist->pollfd, timeout);
 338 }
 339
 340 static struct perf_mmap* perf_evlist__alloc_mmap(struct perf_evlist *evlist, bool overwrite)
 341 {
 342         int i;
 343         struct perf_mmap *map;
 344
 345         map = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap));
 346         if (!map)
 347                 return NULL;
 348
 349         for (i = 0; i < evlist->nr_mmaps; i++) {
 350                 struct perf_mmap *prev = i ? &map[i - 1] : NULL;
 351
 352                 /*
 353                  * When the perf_mmap() call is made we grab one refcount, plus
 354                  * one extra to let perf_mmap__consume() get the last
 355                  * events after all real references (perf_mmap__get()) are
 356                  * dropped.
 357                  *
 358                  * Each PERF_EVENT_IOC_SET_OUTPUT points to this mmap and
 359                  * thus does perf_mmap__get() on it.
 360                  */
 361                 perf_mmap__init(&map[i], prev, overwrite, NULL);
 362         }
 363
 364         return map;
 365 }
 366
 367 static void perf_evlist__set_sid_idx(struct perf_evlist *evlist,
 368                                      struct perf_evsel *evsel, int idx, int cpu,
 369                                      int thread)
 370 {
 371         struct perf_sample_id *sid = SID(evsel, cpu, thread);
 372
 373         sid->idx = idx;
 374         if (evlist->cpus && cpu >= 0)
 375                 sid->cpu = evlist->cpus->map[cpu];
 376         else
 377                 sid->cpu = -1;
 378         if (!evsel->system_wide && evlist->threads && thread >= 0)
 379                 sid->tid = perf_thread_map__pid(evlist->threads, thread);
 380         else
 381                 sid->tid = -1;
 382 }
 383
 384 static struct perf_mmap*
 385 perf_evlist__mmap_cb_get(struct perf_evlist *evlist, bool overwrite, int idx)
 386 {
 387         struct perf_mmap *maps;
 388
 389         maps = overwrite ? evlist->mmap_ovw : evlist->mmap;
 390
 391         if (!maps) {
 392                 maps = perf_evlist__alloc_mmap(evlist, overwrite);
 393                 if (!maps)
 394                         return NULL;
 395
 396                 if (overwrite)
 397                         evlist->mmap_ovw = maps;
 398                 else
 399                         evlist->mmap = maps;
 400         }
 401
 402         return &maps[idx];
 403 }
 404
 405 #define FD(e, x, y) (*(int *) xyarray__entry(e->fd, x, y))
 406
 407 static int
 408 perf_evlist__mmap_cb_mmap(struct perf_mmap *map, struct perf_mmap_param *mp,
 409                           int output, int cpu)
 410 {
 411         return perf_mmap__mmap(map, mp, output, cpu);
 412 }
 413
 414 static void perf_evlist__set_mmap_first(struct perf_evlist *evlist, struct perf_mmap *map,
 415                                         bool overwrite)
 416 {
 417         if (overwrite)
 418                 evlist->mmap_ovw_first = map;
 419         else
 420                 evlist->mmap_first = map;
 421 }
 422
 423 static int
 424 mmap_per_evsel(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
 425                int idx, struct perf_mmap_param *mp, int cpu_idx,
 426                int thread, int *_output, int *_output_overwrite)
 427 {
 428         int evlist_cpu = perf_cpu_map__cpu(evlist->cpus, cpu_idx);
 429         struct perf_evsel *evsel;
 430         int revent;
 431
 432         perf_evlist__for_each_entry(evlist, evsel) {
 433                 bool overwrite = evsel->attr.write_backward;
 434                 struct perf_mmap *map;
 435                 int *output, fd, cpu;
 436
 437                 if (evsel->system_wide && thread)
 438                         continue;
 439
 440                 cpu = perf_cpu_map__idx(evsel->cpus, evlist_cpu);
 441                 if (cpu == -1)
 442                         continue;
 443
 444                 map = ops->get(evlist, overwrite, idx);
 445                 if (map == NULL)
 446                         return -ENOMEM;
 447
 448                 if (overwrite) {
 449                         mp->prot = PROT_READ;
 450                         output   = _output_overwrite;
 451                 } else {
 452                         mp->prot = PROT_READ | PROT_WRITE;
 453                         output   = _output;
 454                 }
 455
 456                 fd = FD(evsel, cpu, thread);
 457
 458                 if (*output == -1) {
 459                         *output = fd;
 460
 461                         /*
 462                          * The last one will be done at perf_mmap__consume(), so that we
 463                          * make sure we don't prevent tools from consuming every last event in
 464                          * the ring buffer.
 465                          *
 466                          * I.e. we can get the POLLHUP meaning that the fd doesn't exist
 467                          * anymore, but the last events for it are still in the ring buffer,
 468                          * waiting to be consumed.
 469                          *
 470                          * Tools can chose to ignore this at their own discretion, but the
 471                          * evlist layer can't just drop it when filtering events in
 472                          * perf_evlist__filter_pollfd().
 473                          */
 474                         refcount_set(&map->refcnt, 2);
 475
 476                         if (ops->mmap(map, mp, *output, evlist_cpu) < 0)
 477                                 return -1;
 478
 479                         if (!idx)
 480                                 perf_evlist__set_mmap_first(evlist, map, overwrite);
 481                 } else {
 482                         if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, *output) != 0)
 483                                 return -1;
 484
 485                         perf_mmap__get(map);
 486                 }
 487
 488                 revent = !overwrite ? POLLIN : 0;
 489
 490                 if (!evsel->system_wide &&
 491                     perf_evlist__add_pollfd(evlist, fd, map, revent) < 0) {
 492                         perf_mmap__put(map);
 493                         return -1;
 494                 }
 495
 496                 if (evsel->attr.read_format & PERF_FORMAT_ID) {
 497                         if (perf_evlist__id_add_fd(evlist, evsel, cpu, thread,
 498                                                    fd) < 0)
 499                                 return -1;
 500                         perf_evlist__set_sid_idx(evlist, evsel, idx, cpu,
 501                                                  thread);
 502                 }
 503         }
 504
 505         return 0;
 506 }
 507
 508 static int
 509 mmap_per_thread(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
 510                 struct perf_mmap_param *mp)
 511 {
 512         int thread;
 513         int nr_threads = perf_thread_map__nr(evlist->threads);
 514
 515         for (thread = 0; thread < nr_threads; thread++) {
 516                 int output = -1;
 517                 int output_overwrite = -1;
 518
 519                 if (ops->idx)
 520                         ops->idx(evlist, mp, thread, false);
 521
 522                 if (mmap_per_evsel(evlist, ops, thread, mp, 0, thread,
 523                                    &output, &output_overwrite))
 524                         goto out_unmap;
 525         }
 526
 527         return 0;
 528
 529 out_unmap:
 530         perf_evlist__munmap(evlist);
 531         return -1;
 532 }
 533
 534 static int
 535 mmap_per_cpu(struct perf_evlist *evlist, struct perf_evlist_mmap_ops *ops,
 536              struct perf_mmap_param *mp)
 537 {
 538         int nr_threads = perf_thread_map__nr(evlist->threads);
 539         int nr_cpus    = perf_cpu_map__nr(evlist->cpus);
 540         int cpu, thread;
 541
 542         for (cpu = 0; cpu < nr_cpus; cpu++) {
 543                 int output = -1;
 544                 int output_overwrite = -1;
 545
 546                 if (ops->idx)
 547                         ops->idx(evlist, mp, cpu, true);
 548
 549                 for (thread = 0; thread < nr_threads; thread++) {
 550                         if (mmap_per_evsel(evlist, ops, cpu, mp, cpu,
 551                                            thread, &output, &output_overwrite))
 552                                 goto out_unmap;
 553                 }
 554         }
 555
 556         return 0;
 557
 558 out_unmap:
 559         perf_evlist__munmap(evlist);
 560         return -1;
 561 }
 562
 563 static int perf_evlist__nr_mmaps(struct perf_evlist *evlist)
 564 {
 565         int nr_mmaps;
 566
 567         nr_mmaps = perf_cpu_map__nr(evlist->cpus);
 568         if (perf_cpu_map__empty(evlist->cpus))
 569                 nr_mmaps = perf_thread_map__nr(evlist->threads);
 570
 571         return nr_mmaps;
 572 }
 573
 574 int perf_evlist__mmap_ops(struct perf_evlist *evlist,
 575                           struct perf_evlist_mmap_ops *ops,
 576                           struct perf_mmap_param *mp)
 577 {
 578         struct perf_evsel *evsel;
 579         const struct perf_cpu_map *cpus = evlist->cpus;
 580         const struct perf_thread_map *threads = evlist->threads;
 581
 582         if (!ops || !ops->get || !ops->mmap)
 583                 return -EINVAL;
 584
 585         mp->mask = evlist->mmap_len - page_size - 1;
 586
 587         evlist->nr_mmaps = perf_evlist__nr_mmaps(evlist);
 588
 589         perf_evlist__for_each_entry(evlist, evsel) {
 590                 if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
 591                     evsel->sample_id == NULL &&
 592                     perf_evsel__alloc_id(evsel, perf_cpu_map__nr(cpus), threads->nr) < 0)
 593                         return -ENOMEM;
 594         }
 595
 596         if (evlist->pollfd.entries == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
 597                 return -ENOMEM;
 598
 599         if (perf_cpu_map__empty(cpus))
 600                 return mmap_per_thread(evlist, ops, mp);
 601
 602         return mmap_per_cpu(evlist, ops, mp);
 603 }
 604
 605 int perf_evlist__mmap(struct perf_evlist *evlist, int pages)
 606 {
 607         struct perf_mmap_param mp;
 608         struct perf_evlist_mmap_ops ops = {
 609                 .get  = perf_evlist__mmap_cb_get,
 610                 .mmap = perf_evlist__mmap_cb_mmap,
 611         };
 612
 613         evlist->mmap_len = (pages + 1) * page_size;
 614
 615         return perf_evlist__mmap_ops(evlist, &ops, &mp);
 616 }
 617
 618 void perf_evlist__munmap(struct perf_evlist *evlist)
 619 {
 620         int i;
 621
 622         if (evlist->mmap) {
 623                 for (i = 0; i < evlist->nr_mmaps; i++)
 624                         perf_mmap__munmap(&evlist->mmap[i]);
 625         }
 626
 627         if (evlist->mmap_ovw) {
 628                 for (i = 0; i < evlist->nr_mmaps; i++)
 629                         perf_mmap__munmap(&evlist->mmap_ovw[i]);
 630         }
 631
 632         zfree(&evlist->mmap);
 633         zfree(&evlist->mmap_ovw);
 634 }
 635
 636 struct perf_mmap*
 637 perf_evlist__next_mmap(struct perf_evlist *evlist, struct perf_mmap *map,
 638                        bool overwrite)
 639 {
 640         if (map)
 641                 return map->next;
 642
 643         return overwrite ? evlist->mmap_ovw_first : evlist->mmap_first;
 644 }