tools/perf/tests/switch-tracking.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <sys/time.h>
   3 #include <sys/prctl.h>
   4 #include <errno.h>
   5 #include <time.h>
   6 #include <stdlib.h>
   7
   8 #include "parse-events.h"
   9 #include "evlist.h"
  10 #include "evsel.h"
  11 #include "thread_map.h"
  12 #include "cpumap.h"
  13 #include "tests.h"
  14
  15 static int spin_sleep(void)
  16 {
  17         struct timeval start, now, diff, maxtime;
  18         struct timespec ts;
  19         int err, i;
  20
  21         maxtime.tv_sec = 0;
  22         maxtime.tv_usec = 50000;
  23
  24         err = gettimeofday(&start, NULL);
  25         if (err)
  26                 return err;
  27
  28         /* Spin for 50ms */
  29         while (1) {
  30                 for (i = 0; i < 1000; i++)
  31                         barrier();
  32
  33                 err = gettimeofday(&now, NULL);
  34                 if (err)
  35                         return err;
  36
  37                 timersub(&now, &start, &diff);
  38                 if (timercmp(&diff, &maxtime, > /* For checkpatch */))
  39                         break;
  40         }
  41
  42         ts.tv_nsec = 50 * 1000 * 1000;
  43         ts.tv_sec = 0;
  44
  45         /* Sleep for 50ms */
  46         err = nanosleep(&ts, NULL);
  47         if (err == EINTR)
  48                 err = 0;
  49
  50         return err;
  51 }
  52
  53 struct switch_tracking {
  54         struct perf_evsel *switch_evsel;
  55         struct perf_evsel *cycles_evsel;
  56         pid_t *tids;
  57         int nr_tids;
  58         int comm_seen[4];
  59         int cycles_before_comm_1;
  60         int cycles_between_comm_2_and_comm_3;
  61         int cycles_after_comm_4;
  62 };
  63
  64 static int check_comm(struct switch_tracking *switch_tracking,
  65                       union perf_event *event, const char *comm, int nr)
  66 {
  67         if (event->header.type == PERF_RECORD_COMM &&
  68             (pid_t)event->comm.pid == getpid() &&
  69             (pid_t)event->comm.tid == getpid() &&
  70             strcmp(event->comm.comm, comm) == 0) {
  71                 if (switch_tracking->comm_seen[nr]) {
  72                         pr_debug("Duplicate comm event\n");
  73                         return -1;
  74                 }
  75                 switch_tracking->comm_seen[nr] = 1;
  76                 pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
  77                 return 1;
  78         }
  79         return 0;
  80 }
  81
  82 static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
  83 {
  84         int i, nr = cpu + 1;
  85
  86         if (cpu < 0)
  87                 return -1;
  88
  89         if (!switch_tracking->tids) {
  90                 switch_tracking->tids = calloc(nr, sizeof(pid_t));
  91                 if (!switch_tracking->tids)
  92                         return -1;
  93                 for (i = 0; i < nr; i++)
  94                         switch_tracking->tids[i] = -1;
  95                 switch_tracking->nr_tids = nr;
  96                 return 0;
  97         }
  98
  99         if (cpu >= switch_tracking->nr_tids) {
 100                 void *addr;
 101
 102                 addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
 103                 if (!addr)
 104                         return -1;
 105                 switch_tracking->tids = addr;
 106                 for (i = switch_tracking->nr_tids; i < nr; i++)
 107                         switch_tracking->tids[i] = -1;
 108                 switch_tracking->nr_tids = nr;
 109                 return 0;
 110         }
 111
 112         return 0;
 113 }
 114
 115 static int process_sample_event(struct perf_evlist *evlist,
 116                                 union perf_event *event,
 117                                 struct switch_tracking *switch_tracking)
 118 {
 119         struct perf_sample sample;
 120         struct perf_evsel *evsel;
 121         pid_t next_tid, prev_tid;
 122         int cpu, err;
 123
 124         if (perf_evlist__parse_sample(evlist, event, &sample)) {
 125                 pr_debug("perf_evlist__parse_sample failed\n");
 126                 return -1;
 127         }
 128
 129         evsel = perf_evlist__id2evsel(evlist, sample.id);
 130         if (evsel == switch_tracking->switch_evsel) {
 131                 next_tid = perf_evsel__intval(evsel, &sample, "next_pid");
 132                 prev_tid = perf_evsel__intval(evsel, &sample, "prev_pid");
 133                 cpu = sample.cpu;
 134                 pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
 135                           cpu, prev_tid, next_tid);
 136                 err = check_cpu(switch_tracking, cpu);
 137                 if (err)
 138                         return err;
 139                 /*
 140                  * Check for no missing sched_switch events i.e. that the
 141                  * evsel->system_wide flag has worked.
 142                  */
 143                 if (switch_tracking->tids[cpu] != -1 &&
 144                     switch_tracking->tids[cpu] != prev_tid) {
 145                         pr_debug("Missing sched_switch events\n");
 146                         return -1;
 147                 }
 148                 switch_tracking->tids[cpu] = next_tid;
 149         }
 150
 151         if (evsel == switch_tracking->cycles_evsel) {
 152                 pr_debug3("cycles event\n");
 153                 if (!switch_tracking->comm_seen[0])
 154                         switch_tracking->cycles_before_comm_1 = 1;
 155                 if (switch_tracking->comm_seen[1] &&
 156                     !switch_tracking->comm_seen[2])
 157                         switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
 158                 if (switch_tracking->comm_seen[3])
 159                         switch_tracking->cycles_after_comm_4 = 1;
 160         }
 161
 162         return 0;
 163 }
 164
 165 static int process_event(struct perf_evlist *evlist, union perf_event *event,
 166                          struct switch_tracking *switch_tracking)
 167 {
 168         if (event->header.type == PERF_RECORD_SAMPLE)
 169                 return process_sample_event(evlist, event, switch_tracking);
 170
 171         if (event->header.type == PERF_RECORD_COMM) {
 172                 int err, done = 0;
 173
 174                 err = check_comm(switch_tracking, event, "Test COMM 1", 0);
 175                 if (err < 0)
 176                         return -1;
 177                 done += err;
 178                 err = check_comm(switch_tracking, event, "Test COMM 2", 1);
 179                 if (err < 0)
 180                         return -1;
 181                 done += err;
 182                 err = check_comm(switch_tracking, event, "Test COMM 3", 2);
 183                 if (err < 0)
 184                         return -1;
 185                 done += err;
 186                 err = check_comm(switch_tracking, event, "Test COMM 4", 3);
 187                 if (err < 0)
 188                         return -1;
 189                 done += err;
 190                 if (done != 1) {
 191                         pr_debug("Unexpected comm event\n");
 192                         return -1;
 193                 }
 194         }
 195
 196         return 0;
 197 }
 198
 199 struct event_node {
 200         struct list_head list;
 201         union perf_event *event;
 202         u64 event_time;
 203 };
 204
 205 static int add_event(struct perf_evlist *evlist, struct list_head *events,
 206                      union perf_event *event)
 207 {
 208         struct perf_sample sample;
 209         struct event_node *node;
 210
 211         node = malloc(sizeof(struct event_node));
 212         if (!node) {
 213                 pr_debug("malloc failed\n");
 214                 return -1;
 215         }
 216         node->event = event;
 217         list_add(&node->list, events);
 218
 219         if (perf_evlist__parse_sample(evlist, event, &sample)) {
 220                 pr_debug("perf_evlist__parse_sample failed\n");
 221                 return -1;
 222         }
 223
 224         if (!sample.time) {
 225                 pr_debug("event with no time\n");
 226                 return -1;
 227         }
 228
 229         node->event_time = sample.time;
 230
 231         return 0;
 232 }
 233
 234 static void free_event_nodes(struct list_head *events)
 235 {
 236         struct event_node *node;
 237
 238         while (!list_empty(events)) {
 239                 node = list_entry(events->next, struct event_node, list);
 240                 list_del(&node->list);
 241                 free(node);
 242         }
 243 }
 244
 245 static int compar(const void *a, const void *b)
 246 {
 247         const struct event_node *nodea = a;
 248         const struct event_node *nodeb = b;
 249         s64 cmp = nodea->event_time - nodeb->event_time;
 250
 251         return cmp;
 252 }
 253
 254 static int process_events(struct perf_evlist *evlist,
 255                           struct switch_tracking *switch_tracking)
 256 {
 257         union perf_event *event;
 258         unsigned pos, cnt = 0;
 259         LIST_HEAD(events);
 260         struct event_node *events_array, *node;
 261         int i, ret;
 262
 263         for (i = 0; i < evlist->nr_mmaps; i++) {
 264                 while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
 265                         cnt += 1;
 266                         ret = add_event(evlist, &events, event);
 267                         perf_evlist__mmap_consume(evlist, i);
 268                         if (ret < 0)
 269                                 goto out_free_nodes;
 270                 }
 271         }
 272
 273         events_array = calloc(cnt, sizeof(struct event_node));
 274         if (!events_array) {
 275                 pr_debug("calloc failed\n");
 276                 ret = -1;
 277                 goto out_free_nodes;
 278         }
 279
 280         pos = 0;
 281         list_for_each_entry(node, &events, list)
 282                 events_array[pos++] = *node;
 283
 284         qsort(events_array, cnt, sizeof(struct event_node), compar);
 285
 286         for (pos = 0; pos < cnt; pos++) {
 287                 ret = process_event(evlist, events_array[pos].event,
 288                                     switch_tracking);
 289                 if (ret < 0)
 290                         goto out_free;
 291         }
 292
 293         ret = 0;
 294 out_free:
 295         pr_debug("%u events recorded\n", cnt);
 296         free(events_array);
 297 out_free_nodes:
 298         free_event_nodes(&events);
 299         return ret;
 300 }
 301
 302 /**
 303  * test__switch_tracking - test using sched_switch and tracking events.
 304  *
 305  * This function implements a test that checks that sched_switch events and
 306  * tracking events can be recorded for a workload (current process) using the
 307  * evsel->system_wide and evsel->tracking flags (respectively) with other events
 308  * sometimes enabled or disabled.
 309  */
 310 int test__switch_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
 311 {
 312         const char *sched_switch = "sched:sched_switch";
 313         struct switch_tracking switch_tracking = { .tids = NULL, };
 314         struct record_opts opts = {
 315                 .mmap_pages          = UINT_MAX,
 316                 .user_freq           = UINT_MAX,
 317                 .user_interval       = ULLONG_MAX,
 318                 .freq                = 4000,
 319                 .target              = {
 320                         .uses_mmap   = true,
 321                 },
 322         };
 323         struct thread_map *threads = NULL;
 324         struct cpu_map *cpus = NULL;
 325         struct perf_evlist *evlist = NULL;
 326         struct perf_evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
 327         struct perf_evsel *switch_evsel, *tracking_evsel;
 328         const char *comm;
 329         int err = -1;
 330
 331         threads = thread_map__new(-1, getpid(), UINT_MAX);
 332         if (!threads) {
 333                 pr_debug("thread_map__new failed!\n");
 334                 goto out_err;
 335         }
 336
 337         cpus = cpu_map__new(NULL);
 338         if (!cpus) {
 339                 pr_debug("cpu_map__new failed!\n");
 340                 goto out_err;
 341         }
 342
 343         evlist = perf_evlist__new();
 344         if (!evlist) {
 345                 pr_debug("perf_evlist__new failed!\n");
 346                 goto out_err;
 347         }
 348
 349         perf_evlist__set_maps(evlist, cpus, threads);
 350
 351         /* First event */
 352         err = parse_events(evlist, "cpu-clock:u", NULL);
 353         if (err) {
 354                 pr_debug("Failed to parse event dummy:u\n");
 355                 goto out_err;
 356         }
 357
 358         cpu_clocks_evsel = perf_evlist__last(evlist);
 359
 360         /* Second event */
 361         err = parse_events(evlist, "cycles:u", NULL);
 362         if (err) {
 363                 pr_debug("Failed to parse event cycles:u\n");
 364                 goto out_err;
 365         }
 366
 367         cycles_evsel = perf_evlist__last(evlist);
 368
 369         /* Third event */
 370         if (!perf_evlist__can_select_event(evlist, sched_switch)) {
 371                 pr_debug("No sched_switch\n");
 372                 err = 0;
 373                 goto out;
 374         }
 375
 376         err = parse_events(evlist, sched_switch, NULL);
 377         if (err) {
 378                 pr_debug("Failed to parse event %s\n", sched_switch);
 379                 goto out_err;
 380         }
 381
 382         switch_evsel = perf_evlist__last(evlist);
 383
 384         perf_evsel__set_sample_bit(switch_evsel, CPU);
 385         perf_evsel__set_sample_bit(switch_evsel, TIME);
 386
 387         switch_evsel->system_wide = true;
 388         switch_evsel->no_aux_samples = true;
 389         switch_evsel->immediate = true;
 390
 391         /* Test moving an event to the front */
 392         if (cycles_evsel == perf_evlist__first(evlist)) {
 393                 pr_debug("cycles event already at front");
 394                 goto out_err;
 395         }
 396         perf_evlist__to_front(evlist, cycles_evsel);
 397         if (cycles_evsel != perf_evlist__first(evlist)) {
 398                 pr_debug("Failed to move cycles event to front");
 399                 goto out_err;
 400         }
 401
 402         perf_evsel__set_sample_bit(cycles_evsel, CPU);
 403         perf_evsel__set_sample_bit(cycles_evsel, TIME);
 404
 405         /* Fourth event */
 406         err = parse_events(evlist, "dummy:u", NULL);
 407         if (err) {
 408                 pr_debug("Failed to parse event dummy:u\n");
 409                 goto out_err;
 410         }
 411
 412         tracking_evsel = perf_evlist__last(evlist);
 413
 414         perf_evlist__set_tracking_event(evlist, tracking_evsel);
 415
 416         tracking_evsel->attr.freq = 0;
 417         tracking_evsel->attr.sample_period = 1;
 418
 419         perf_evsel__set_sample_bit(tracking_evsel, TIME);
 420
 421         /* Config events */
 422         perf_evlist__config(evlist, &opts, NULL);
 423
 424         /* Check moved event is still at the front */
 425         if (cycles_evsel != perf_evlist__first(evlist)) {
 426                 pr_debug("Front event no longer at front");
 427                 goto out_err;
 428         }
 429
 430         /* Check tracking event is tracking */
 431         if (!tracking_evsel->attr.mmap || !tracking_evsel->attr.comm) {
 432                 pr_debug("Tracking event not tracking\n");
 433                 goto out_err;
 434         }
 435
 436         /* Check non-tracking events are not tracking */
 437         evlist__for_each_entry(evlist, evsel) {
 438                 if (evsel != tracking_evsel) {
 439                         if (evsel->attr.mmap || evsel->attr.comm) {
 440                                 pr_debug("Non-tracking event is tracking\n");
 441                                 goto out_err;
 442                         }
 443                 }
 444         }
 445
 446         if (perf_evlist__open(evlist) < 0) {
 447                 pr_debug("Not supported\n");
 448                 err = 0;
 449                 goto out;
 450         }
 451
 452         err = perf_evlist__mmap(evlist, UINT_MAX, false);
 453         if (err) {
 454                 pr_debug("perf_evlist__mmap failed!\n");
 455                 goto out_err;
 456         }
 457
 458         perf_evlist__enable(evlist);
 459
 460         err = perf_evsel__disable(cpu_clocks_evsel);
 461         if (err) {
 462                 pr_debug("perf_evlist__disable_event failed!\n");
 463                 goto out_err;
 464         }
 465
 466         err = spin_sleep();
 467         if (err) {
 468                 pr_debug("spin_sleep failed!\n");
 469                 goto out_err;
 470         }
 471
 472         comm = "Test COMM 1";
 473         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 474         if (err) {
 475                 pr_debug("PR_SET_NAME failed!\n");
 476                 goto out_err;
 477         }
 478
 479         err = perf_evsel__disable(cycles_evsel);
 480         if (err) {
 481                 pr_debug("perf_evlist__disable_event failed!\n");
 482                 goto out_err;
 483         }
 484
 485         comm = "Test COMM 2";
 486         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 487         if (err) {
 488                 pr_debug("PR_SET_NAME failed!\n");
 489                 goto out_err;
 490         }
 491
 492         err = spin_sleep();
 493         if (err) {
 494                 pr_debug("spin_sleep failed!\n");
 495                 goto out_err;
 496         }
 497
 498         comm = "Test COMM 3";
 499         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 500         if (err) {
 501                 pr_debug("PR_SET_NAME failed!\n");
 502                 goto out_err;
 503         }
 504
 505         err = perf_evsel__enable(cycles_evsel);
 506         if (err) {
 507                 pr_debug("perf_evlist__disable_event failed!\n");
 508                 goto out_err;
 509         }
 510
 511         comm = "Test COMM 4";
 512         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 513         if (err) {
 514                 pr_debug("PR_SET_NAME failed!\n");
 515                 goto out_err;
 516         }
 517
 518         err = spin_sleep();
 519         if (err) {
 520                 pr_debug("spin_sleep failed!\n");
 521                 goto out_err;
 522         }
 523
 524         perf_evlist__disable(evlist);
 525
 526         switch_tracking.switch_evsel = switch_evsel;
 527         switch_tracking.cycles_evsel = cycles_evsel;
 528
 529         err = process_events(evlist, &switch_tracking);
 530
 531         zfree(&switch_tracking.tids);
 532
 533         if (err)
 534                 goto out_err;
 535
 536         /* Check all 4 comm events were seen i.e. that evsel->tracking works */
 537         if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
 538             !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
 539                 pr_debug("Missing comm events\n");
 540                 goto out_err;
 541         }
 542
 543         /* Check cycles event got enabled */
 544         if (!switch_tracking.cycles_before_comm_1) {
 545                 pr_debug("Missing cycles events\n");
 546                 goto out_err;
 547         }
 548
 549         /* Check cycles event got disabled */
 550         if (switch_tracking.cycles_between_comm_2_and_comm_3) {
 551                 pr_debug("cycles events even though event was disabled\n");
 552                 goto out_err;
 553         }
 554
 555         /* Check cycles event got enabled again */
 556         if (!switch_tracking.cycles_after_comm_4) {
 557                 pr_debug("Missing cycles events\n");
 558                 goto out_err;
 559         }
 560 out:
 561         if (evlist) {
 562                 perf_evlist__disable(evlist);
 563                 perf_evlist__delete(evlist);
 564         } else {
 565                 cpu_map__put(cpus);
 566                 thread_map__put(threads);
 567         }
 568
 569         return err;
 570
 571 out_err:
 572         err = -1;
 573         goto out;
 574 }