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 <limits.h>
   6 #include <time.h>
   7 #include <stdlib.h>
   8 #include <linux/zalloc.h>
   9 #include <perf/cpumap.h>
  10 #include <perf/evlist.h>
  11 #include <perf/mmap.h>
  12
  13 #include "debug.h"
  14 #include "parse-events.h"
  15 #include "evlist.h"
  16 #include "evsel.h"
  17 #include "thread_map.h"
  18 #include "record.h"
  19 #include "tests.h"
  20 #include "util/mmap.h"
  21 #include "pmu.h"
  22
  23 static int spin_sleep(void)
  24 {
  25         struct timeval start, now, diff, maxtime;
  26         struct timespec ts;
  27         int err, i;
  28
  29         maxtime.tv_sec = 0;
  30         maxtime.tv_usec = 50000;
  31
  32         err = gettimeofday(&start, NULL);
  33         if (err)
  34                 return err;
  35
  36         /* Spin for 50ms */
  37         while (1) {
  38                 for (i = 0; i < 1000; i++)
  39                         barrier();
  40
  41                 err = gettimeofday(&now, NULL);
  42                 if (err)
  43                         return err;
  44
  45                 timersub(&now, &start, &diff);
  46                 if (timercmp(&diff, &maxtime, > /* For checkpatch */))
  47                         break;
  48         }
  49
  50         ts.tv_nsec = 50 * 1000 * 1000;
  51         ts.tv_sec = 0;
  52
  53         /* Sleep for 50ms */
  54         err = nanosleep(&ts, NULL);
  55         if (err == EINTR)
  56                 err = 0;
  57
  58         return err;
  59 }
  60
  61 struct switch_tracking {
  62         struct evsel *switch_evsel;
  63         struct evsel *cycles_evsel;
  64         pid_t *tids;
  65         int nr_tids;
  66         int comm_seen[4];
  67         int cycles_before_comm_1;
  68         int cycles_between_comm_2_and_comm_3;
  69         int cycles_after_comm_4;
  70 };
  71
  72 static int check_comm(struct switch_tracking *switch_tracking,
  73                       union perf_event *event, const char *comm, int nr)
  74 {
  75         if (event->header.type == PERF_RECORD_COMM &&
  76             (pid_t)event->comm.pid == getpid() &&
  77             (pid_t)event->comm.tid == getpid() &&
  78             strcmp(event->comm.comm, comm) == 0) {
  79                 if (switch_tracking->comm_seen[nr]) {
  80                         pr_debug("Duplicate comm event\n");
  81                         return -1;
  82                 }
  83                 switch_tracking->comm_seen[nr] = 1;
  84                 pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
  85                 return 1;
  86         }
  87         return 0;
  88 }
  89
  90 static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
  91 {
  92         int i, nr = cpu + 1;
  93
  94         if (cpu < 0)
  95                 return -1;
  96
  97         if (!switch_tracking->tids) {
  98                 switch_tracking->tids = calloc(nr, sizeof(pid_t));
  99                 if (!switch_tracking->tids)
 100                         return -1;
 101                 for (i = 0; i < nr; i++)
 102                         switch_tracking->tids[i] = -1;
 103                 switch_tracking->nr_tids = nr;
 104                 return 0;
 105         }
 106
 107         if (cpu >= switch_tracking->nr_tids) {
 108                 void *addr;
 109
 110                 addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
 111                 if (!addr)
 112                         return -1;
 113                 switch_tracking->tids = addr;
 114                 for (i = switch_tracking->nr_tids; i < nr; i++)
 115                         switch_tracking->tids[i] = -1;
 116                 switch_tracking->nr_tids = nr;
 117                 return 0;
 118         }
 119
 120         return 0;
 121 }
 122
 123 static int process_sample_event(struct evlist *evlist,
 124                                 union perf_event *event,
 125                                 struct switch_tracking *switch_tracking)
 126 {
 127         struct perf_sample sample;
 128         struct evsel *evsel;
 129         pid_t next_tid, prev_tid;
 130         int cpu, err;
 131
 132         if (evlist__parse_sample(evlist, event, &sample)) {
 133                 pr_debug("evlist__parse_sample failed\n");
 134                 return -1;
 135         }
 136
 137         evsel = evlist__id2evsel(evlist, sample.id);
 138         if (evsel == switch_tracking->switch_evsel) {
 139                 next_tid = evsel__intval(evsel, &sample, "next_pid");
 140                 prev_tid = evsel__intval(evsel, &sample, "prev_pid");
 141                 cpu = sample.cpu;
 142                 pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
 143                           cpu, prev_tid, next_tid);
 144                 err = check_cpu(switch_tracking, cpu);
 145                 if (err)
 146                         return err;
 147                 /*
 148                  * Check for no missing sched_switch events i.e. that the
 149                  * evsel->core.system_wide flag has worked.
 150                  */
 151                 if (switch_tracking->tids[cpu] != -1 &&
 152                     switch_tracking->tids[cpu] != prev_tid) {
 153                         pr_debug("Missing sched_switch events\n");
 154                         return -1;
 155                 }
 156                 switch_tracking->tids[cpu] = next_tid;
 157         }
 158
 159         if (evsel == switch_tracking->cycles_evsel) {
 160                 pr_debug3("cycles event\n");
 161                 if (!switch_tracking->comm_seen[0])
 162                         switch_tracking->cycles_before_comm_1 = 1;
 163                 if (switch_tracking->comm_seen[1] &&
 164                     !switch_tracking->comm_seen[2])
 165                         switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
 166                 if (switch_tracking->comm_seen[3])
 167                         switch_tracking->cycles_after_comm_4 = 1;
 168         }
 169
 170         return 0;
 171 }
 172
 173 static int process_event(struct evlist *evlist, union perf_event *event,
 174                          struct switch_tracking *switch_tracking)
 175 {
 176         if (event->header.type == PERF_RECORD_SAMPLE)
 177                 return process_sample_event(evlist, event, switch_tracking);
 178
 179         if (event->header.type == PERF_RECORD_COMM) {
 180                 int err, done = 0;
 181
 182                 err = check_comm(switch_tracking, event, "Test COMM 1", 0);
 183                 if (err < 0)
 184                         return -1;
 185                 done += err;
 186                 err = check_comm(switch_tracking, event, "Test COMM 2", 1);
 187                 if (err < 0)
 188                         return -1;
 189                 done += err;
 190                 err = check_comm(switch_tracking, event, "Test COMM 3", 2);
 191                 if (err < 0)
 192                         return -1;
 193                 done += err;
 194                 err = check_comm(switch_tracking, event, "Test COMM 4", 3);
 195                 if (err < 0)
 196                         return -1;
 197                 done += err;
 198                 if (done != 1) {
 199                         pr_debug("Unexpected comm event\n");
 200                         return -1;
 201                 }
 202         }
 203
 204         return 0;
 205 }
 206
 207 struct event_node {
 208         struct list_head list;
 209         union perf_event *event;
 210         u64 event_time;
 211 };
 212
 213 static int add_event(struct evlist *evlist, struct list_head *events,
 214                      union perf_event *event)
 215 {
 216         struct perf_sample sample;
 217         struct event_node *node;
 218
 219         node = malloc(sizeof(struct event_node));
 220         if (!node) {
 221                 pr_debug("malloc failed\n");
 222                 return -1;
 223         }
 224         node->event = event;
 225         list_add(&node->list, events);
 226
 227         if (evlist__parse_sample(evlist, event, &sample)) {
 228                 pr_debug("evlist__parse_sample failed\n");
 229                 return -1;
 230         }
 231
 232         if (!sample.time) {
 233                 pr_debug("event with no time\n");
 234                 return -1;
 235         }
 236
 237         node->event_time = sample.time;
 238
 239         return 0;
 240 }
 241
 242 static void free_event_nodes(struct list_head *events)
 243 {
 244         struct event_node *node;
 245
 246         while (!list_empty(events)) {
 247                 node = list_entry(events->next, struct event_node, list);
 248                 list_del_init(&node->list);
 249                 free(node);
 250         }
 251 }
 252
 253 static int compar(const void *a, const void *b)
 254 {
 255         const struct event_node *nodea = a;
 256         const struct event_node *nodeb = b;
 257         s64 cmp = nodea->event_time - nodeb->event_time;
 258
 259         return cmp;
 260 }
 261
 262 static int process_events(struct evlist *evlist,
 263                           struct switch_tracking *switch_tracking)
 264 {
 265         union perf_event *event;
 266         unsigned pos, cnt = 0;
 267         LIST_HEAD(events);
 268         struct event_node *events_array, *node;
 269         struct mmap *md;
 270         int i, ret;
 271
 272         for (i = 0; i < evlist->core.nr_mmaps; i++) {
 273                 md = &evlist->mmap[i];
 274                 if (perf_mmap__read_init(&md->core) < 0)
 275                         continue;
 276
 277                 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
 278                         cnt += 1;
 279                         ret = add_event(evlist, &events, event);
 280                          perf_mmap__consume(&md->core);
 281                         if (ret < 0)
 282                                 goto out_free_nodes;
 283                 }
 284                 perf_mmap__read_done(&md->core);
 285         }
 286
 287         events_array = calloc(cnt, sizeof(struct event_node));
 288         if (!events_array) {
 289                 pr_debug("calloc failed\n");
 290                 ret = -1;
 291                 goto out_free_nodes;
 292         }
 293
 294         pos = 0;
 295         list_for_each_entry(node, &events, list)
 296                 events_array[pos++] = *node;
 297
 298         qsort(events_array, cnt, sizeof(struct event_node), compar);
 299
 300         for (pos = 0; pos < cnt; pos++) {
 301                 ret = process_event(evlist, events_array[pos].event,
 302                                     switch_tracking);
 303                 if (ret < 0)
 304                         goto out_free;
 305         }
 306
 307         ret = 0;
 308 out_free:
 309         pr_debug("%u events recorded\n", cnt);
 310         free(events_array);
 311 out_free_nodes:
 312         free_event_nodes(&events);
 313         return ret;
 314 }
 315
 316 /**
 317  * test__switch_tracking - test using sched_switch and tracking events.
 318  *
 319  * This function implements a test that checks that sched_switch events and
 320  * tracking events can be recorded for a workload (current process) using the
 321  * evsel->core.system_wide and evsel->tracking flags (respectively) with other events
 322  * sometimes enabled or disabled.
 323  */
 324 int test__switch_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
 325 {
 326         const char *sched_switch = "sched:sched_switch";
 327         struct switch_tracking switch_tracking = { .tids = NULL, };
 328         struct record_opts opts = {
 329                 .mmap_pages          = UINT_MAX,
 330                 .user_freq           = UINT_MAX,
 331                 .user_interval       = ULLONG_MAX,
 332                 .freq                = 4000,
 333                 .target              = {
 334                         .uses_mmap   = true,
 335                 },
 336         };
 337         struct perf_thread_map *threads = NULL;
 338         struct perf_cpu_map *cpus = NULL;
 339         struct evlist *evlist = NULL;
 340         struct evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
 341         struct evsel *switch_evsel, *tracking_evsel;
 342         const char *comm;
 343         int err = -1;
 344
 345         threads = thread_map__new(-1, getpid(), UINT_MAX);
 346         if (!threads) {
 347                 pr_debug("thread_map__new failed!\n");
 348                 goto out_err;
 349         }
 350
 351         cpus = perf_cpu_map__new(NULL);
 352         if (!cpus) {
 353                 pr_debug("perf_cpu_map__new failed!\n");
 354                 goto out_err;
 355         }
 356
 357         evlist = evlist__new();
 358         if (!evlist) {
 359                 pr_debug("evlist__new failed!\n");
 360                 goto out_err;
 361         }
 362
 363         perf_evlist__set_maps(&evlist->core, cpus, threads);
 364
 365         /* First event */
 366         err = parse_events(evlist, "cpu-clock:u", NULL);
 367         if (err) {
 368                 pr_debug("Failed to parse event dummy:u\n");
 369                 goto out_err;
 370         }
 371
 372         cpu_clocks_evsel = evlist__last(evlist);
 373
 374         /* Second event */
 375         if (perf_pmu__has_hybrid())
 376                 err = parse_events(evlist, "cpu_core/cycles/u", NULL);
 377         else
 378                 err = parse_events(evlist, "cycles:u", NULL);
 379         if (err) {
 380                 pr_debug("Failed to parse event cycles:u\n");
 381                 goto out_err;
 382         }
 383
 384         cycles_evsel = evlist__last(evlist);
 385
 386         /* Third event */
 387         if (!evlist__can_select_event(evlist, sched_switch)) {
 388                 pr_debug("No sched_switch\n");
 389                 err = 0;
 390                 goto out;
 391         }
 392
 393         err = parse_events(evlist, sched_switch, NULL);
 394         if (err) {
 395                 pr_debug("Failed to parse event %s\n", sched_switch);
 396                 goto out_err;
 397         }
 398
 399         switch_evsel = evlist__last(evlist);
 400
 401         evsel__set_sample_bit(switch_evsel, CPU);
 402         evsel__set_sample_bit(switch_evsel, TIME);
 403
 404         switch_evsel->core.system_wide = true;
 405         switch_evsel->no_aux_samples = true;
 406         switch_evsel->immediate = true;
 407
 408         /* Test moving an event to the front */
 409         if (cycles_evsel == evlist__first(evlist)) {
 410                 pr_debug("cycles event already at front");
 411                 goto out_err;
 412         }
 413         evlist__to_front(evlist, cycles_evsel);
 414         if (cycles_evsel != evlist__first(evlist)) {
 415                 pr_debug("Failed to move cycles event to front");
 416                 goto out_err;
 417         }
 418
 419         evsel__set_sample_bit(cycles_evsel, CPU);
 420         evsel__set_sample_bit(cycles_evsel, TIME);
 421
 422         /* Fourth event */
 423         err = parse_events(evlist, "dummy:u", NULL);
 424         if (err) {
 425                 pr_debug("Failed to parse event dummy:u\n");
 426                 goto out_err;
 427         }
 428
 429         tracking_evsel = evlist__last(evlist);
 430
 431         evlist__set_tracking_event(evlist, tracking_evsel);
 432
 433         tracking_evsel->core.attr.freq = 0;
 434         tracking_evsel->core.attr.sample_period = 1;
 435
 436         evsel__set_sample_bit(tracking_evsel, TIME);
 437
 438         /* Config events */
 439         evlist__config(evlist, &opts, NULL);
 440
 441         /* Check moved event is still at the front */
 442         if (cycles_evsel != evlist__first(evlist)) {
 443                 pr_debug("Front event no longer at front");
 444                 goto out_err;
 445         }
 446
 447         /* Check tracking event is tracking */
 448         if (!tracking_evsel->core.attr.mmap || !tracking_evsel->core.attr.comm) {
 449                 pr_debug("Tracking event not tracking\n");
 450                 goto out_err;
 451         }
 452
 453         /* Check non-tracking events are not tracking */
 454         evlist__for_each_entry(evlist, evsel) {
 455                 if (evsel != tracking_evsel) {
 456                         if (evsel->core.attr.mmap || evsel->core.attr.comm) {
 457                                 pr_debug("Non-tracking event is tracking\n");
 458                                 goto out_err;
 459                         }
 460                 }
 461         }
 462
 463         if (evlist__open(evlist) < 0) {
 464                 pr_debug("Not supported\n");
 465                 err = 0;
 466                 goto out;
 467         }
 468
 469         err = evlist__mmap(evlist, UINT_MAX);
 470         if (err) {
 471                 pr_debug("evlist__mmap failed!\n");
 472                 goto out_err;
 473         }
 474
 475         evlist__enable(evlist);
 476
 477         err = evsel__disable(cpu_clocks_evsel);
 478         if (err) {
 479                 pr_debug("perf_evlist__disable_event failed!\n");
 480                 goto out_err;
 481         }
 482
 483         err = spin_sleep();
 484         if (err) {
 485                 pr_debug("spin_sleep failed!\n");
 486                 goto out_err;
 487         }
 488
 489         comm = "Test COMM 1";
 490         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 491         if (err) {
 492                 pr_debug("PR_SET_NAME failed!\n");
 493                 goto out_err;
 494         }
 495
 496         err = evsel__disable(cycles_evsel);
 497         if (err) {
 498                 pr_debug("perf_evlist__disable_event failed!\n");
 499                 goto out_err;
 500         }
 501
 502         comm = "Test COMM 2";
 503         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 504         if (err) {
 505                 pr_debug("PR_SET_NAME failed!\n");
 506                 goto out_err;
 507         }
 508
 509         err = spin_sleep();
 510         if (err) {
 511                 pr_debug("spin_sleep failed!\n");
 512                 goto out_err;
 513         }
 514
 515         comm = "Test COMM 3";
 516         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 517         if (err) {
 518                 pr_debug("PR_SET_NAME failed!\n");
 519                 goto out_err;
 520         }
 521
 522         err = evsel__enable(cycles_evsel);
 523         if (err) {
 524                 pr_debug("perf_evlist__disable_event failed!\n");
 525                 goto out_err;
 526         }
 527
 528         comm = "Test COMM 4";
 529         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 530         if (err) {
 531                 pr_debug("PR_SET_NAME failed!\n");
 532                 goto out_err;
 533         }
 534
 535         err = spin_sleep();
 536         if (err) {
 537                 pr_debug("spin_sleep failed!\n");
 538                 goto out_err;
 539         }
 540
 541         evlist__disable(evlist);
 542
 543         switch_tracking.switch_evsel = switch_evsel;
 544         switch_tracking.cycles_evsel = cycles_evsel;
 545
 546         err = process_events(evlist, &switch_tracking);
 547
 548         zfree(&switch_tracking.tids);
 549
 550         if (err)
 551                 goto out_err;
 552
 553         /* Check all 4 comm events were seen i.e. that evsel->tracking works */
 554         if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
 555             !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
 556                 pr_debug("Missing comm events\n");
 557                 goto out_err;
 558         }
 559
 560         /* Check cycles event got enabled */
 561         if (!switch_tracking.cycles_before_comm_1) {
 562                 pr_debug("Missing cycles events\n");
 563                 goto out_err;
 564         }
 565
 566         /* Check cycles event got disabled */
 567         if (switch_tracking.cycles_between_comm_2_and_comm_3) {
 568                 pr_debug("cycles events even though event was disabled\n");
 569                 goto out_err;
 570         }
 571
 572         /* Check cycles event got enabled again */
 573         if (!switch_tracking.cycles_after_comm_4) {
 574                 pr_debug("Missing cycles events\n");
 575                 goto out_err;
 576         }
 577 out:
 578         if (evlist) {
 579                 evlist__disable(evlist);
 580                 evlist__delete(evlist);
 581         }
 582         perf_cpu_map__put(cpus);
 583         perf_thread_map__put(threads);
 584
 585         return err;
 586
 587 out_err:
 588         err = -1;
 589         goto out;
 590 }