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
  22 static int spin_sleep(void)
  23 {
  24         struct timeval start, now, diff, maxtime;
  25         struct timespec ts;
  26         int err, i;
  27
  28         maxtime.tv_sec = 0;
  29         maxtime.tv_usec = 50000;
  30
  31         err = gettimeofday(&start, NULL);
  32         if (err)
  33                 return err;
  34
  35         /* Spin for 50ms */
  36         while (1) {
  37                 for (i = 0; i < 1000; i++)
  38                         barrier();
  39
  40                 err = gettimeofday(&now, NULL);
  41                 if (err)
  42                         return err;
  43
  44                 timersub(&now, &start, &diff);
  45                 if (timercmp(&diff, &maxtime, > /* For checkpatch */))
  46                         break;
  47         }
  48
  49         ts.tv_nsec = 50 * 1000 * 1000;
  50         ts.tv_sec = 0;
  51
  52         /* Sleep for 50ms */
  53         err = nanosleep(&ts, NULL);
  54         if (err == EINTR)
  55                 err = 0;
  56
  57         return err;
  58 }
  59
  60 struct switch_tracking {
  61         struct evsel *switch_evsel;
  62         struct evsel *cycles_evsel;
  63         pid_t *tids;
  64         int nr_tids;
  65         int comm_seen[4];
  66         int cycles_before_comm_1;
  67         int cycles_between_comm_2_and_comm_3;
  68         int cycles_after_comm_4;
  69 };
  70
  71 static int check_comm(struct switch_tracking *switch_tracking,
  72                       union perf_event *event, const char *comm, int nr)
  73 {
  74         if (event->header.type == PERF_RECORD_COMM &&
  75             (pid_t)event->comm.pid == getpid() &&
  76             (pid_t)event->comm.tid == getpid() &&
  77             strcmp(event->comm.comm, comm) == 0) {
  78                 if (switch_tracking->comm_seen[nr]) {
  79                         pr_debug("Duplicate comm event\n");
  80                         return -1;
  81                 }
  82                 switch_tracking->comm_seen[nr] = 1;
  83                 pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
  84                 return 1;
  85         }
  86         return 0;
  87 }
  88
  89 static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
  90 {
  91         int i, nr = cpu + 1;
  92
  93         if (cpu < 0)
  94                 return -1;
  95
  96         if (!switch_tracking->tids) {
  97                 switch_tracking->tids = calloc(nr, sizeof(pid_t));
  98                 if (!switch_tracking->tids)
  99                         return -1;
 100                 for (i = 0; i < nr; i++)
 101                         switch_tracking->tids[i] = -1;
 102                 switch_tracking->nr_tids = nr;
 103                 return 0;
 104         }
 105
 106         if (cpu >= switch_tracking->nr_tids) {
 107                 void *addr;
 108
 109                 addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
 110                 if (!addr)
 111                         return -1;
 112                 switch_tracking->tids = addr;
 113                 for (i = switch_tracking->nr_tids; i < nr; i++)
 114                         switch_tracking->tids[i] = -1;
 115                 switch_tracking->nr_tids = nr;
 116                 return 0;
 117         }
 118
 119         return 0;
 120 }
 121
 122 static int process_sample_event(struct evlist *evlist,
 123                                 union perf_event *event,
 124                                 struct switch_tracking *switch_tracking)
 125 {
 126         struct perf_sample sample;
 127         struct evsel *evsel;
 128         pid_t next_tid, prev_tid;
 129         int cpu, err;
 130
 131         if (perf_evlist__parse_sample(evlist, event, &sample)) {
 132                 pr_debug("perf_evlist__parse_sample failed\n");
 133                 return -1;
 134         }
 135
 136         evsel = perf_evlist__id2evsel(evlist, sample.id);
 137         if (evsel == switch_tracking->switch_evsel) {
 138                 next_tid = evsel__intval(evsel, &sample, "next_pid");
 139                 prev_tid = evsel__intval(evsel, &sample, "prev_pid");
 140                 cpu = sample.cpu;
 141                 pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
 142                           cpu, prev_tid, next_tid);
 143                 err = check_cpu(switch_tracking, cpu);
 144                 if (err)
 145                         return err;
 146                 /*
 147                  * Check for no missing sched_switch events i.e. that the
 148                  * evsel->core.system_wide flag has worked.
 149                  */
 150                 if (switch_tracking->tids[cpu] != -1 &&
 151                     switch_tracking->tids[cpu] != prev_tid) {
 152                         pr_debug("Missing sched_switch events\n");
 153                         return -1;
 154                 }
 155                 switch_tracking->tids[cpu] = next_tid;
 156         }
 157
 158         if (evsel == switch_tracking->cycles_evsel) {
 159                 pr_debug3("cycles event\n");
 160                 if (!switch_tracking->comm_seen[0])
 161                         switch_tracking->cycles_before_comm_1 = 1;
 162                 if (switch_tracking->comm_seen[1] &&
 163                     !switch_tracking->comm_seen[2])
 164                         switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
 165                 if (switch_tracking->comm_seen[3])
 166                         switch_tracking->cycles_after_comm_4 = 1;
 167         }
 168
 169         return 0;
 170 }
 171
 172 static int process_event(struct evlist *evlist, union perf_event *event,
 173                          struct switch_tracking *switch_tracking)
 174 {
 175         if (event->header.type == PERF_RECORD_SAMPLE)
 176                 return process_sample_event(evlist, event, switch_tracking);
 177
 178         if (event->header.type == PERF_RECORD_COMM) {
 179                 int err, done = 0;
 180
 181                 err = check_comm(switch_tracking, event, "Test COMM 1", 0);
 182                 if (err < 0)
 183                         return -1;
 184                 done += err;
 185                 err = check_comm(switch_tracking, event, "Test COMM 2", 1);
 186                 if (err < 0)
 187                         return -1;
 188                 done += err;
 189                 err = check_comm(switch_tracking, event, "Test COMM 3", 2);
 190                 if (err < 0)
 191                         return -1;
 192                 done += err;
 193                 err = check_comm(switch_tracking, event, "Test COMM 4", 3);
 194                 if (err < 0)
 195                         return -1;
 196                 done += err;
 197                 if (done != 1) {
 198                         pr_debug("Unexpected comm event\n");
 199                         return -1;
 200                 }
 201         }
 202
 203         return 0;
 204 }
 205
 206 struct event_node {
 207         struct list_head list;
 208         union perf_event *event;
 209         u64 event_time;
 210 };
 211
 212 static int add_event(struct evlist *evlist, struct list_head *events,
 213                      union perf_event *event)
 214 {
 215         struct perf_sample sample;
 216         struct event_node *node;
 217
 218         node = malloc(sizeof(struct event_node));
 219         if (!node) {
 220                 pr_debug("malloc failed\n");
 221                 return -1;
 222         }
 223         node->event = event;
 224         list_add(&node->list, events);
 225
 226         if (perf_evlist__parse_sample(evlist, event, &sample)) {
 227                 pr_debug("perf_evlist__parse_sample failed\n");
 228                 return -1;
 229         }
 230
 231         if (!sample.time) {
 232                 pr_debug("event with no time\n");
 233                 return -1;
 234         }
 235
 236         node->event_time = sample.time;
 237
 238         return 0;
 239 }
 240
 241 static void free_event_nodes(struct list_head *events)
 242 {
 243         struct event_node *node;
 244
 245         while (!list_empty(events)) {
 246                 node = list_entry(events->next, struct event_node, list);
 247                 list_del_init(&node->list);
 248                 free(node);
 249         }
 250 }
 251
 252 static int compar(const void *a, const void *b)
 253 {
 254         const struct event_node *nodea = a;
 255         const struct event_node *nodeb = b;
 256         s64 cmp = nodea->event_time - nodeb->event_time;
 257
 258         return cmp;
 259 }
 260
 261 static int process_events(struct evlist *evlist,
 262                           struct switch_tracking *switch_tracking)
 263 {
 264         union perf_event *event;
 265         unsigned pos, cnt = 0;
 266         LIST_HEAD(events);
 267         struct event_node *events_array, *node;
 268         struct mmap *md;
 269         int i, ret;
 270
 271         for (i = 0; i < evlist->core.nr_mmaps; i++) {
 272                 md = &evlist->mmap[i];
 273                 if (perf_mmap__read_init(&md->core) < 0)
 274                         continue;
 275
 276                 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
 277                         cnt += 1;
 278                         ret = add_event(evlist, &events, event);
 279                          perf_mmap__consume(&md->core);
 280                         if (ret < 0)
 281                                 goto out_free_nodes;
 282                 }
 283                 perf_mmap__read_done(&md->core);
 284         }
 285
 286         events_array = calloc(cnt, sizeof(struct event_node));
 287         if (!events_array) {
 288                 pr_debug("calloc failed\n");
 289                 ret = -1;
 290                 goto out_free_nodes;
 291         }
 292
 293         pos = 0;
 294         list_for_each_entry(node, &events, list)
 295                 events_array[pos++] = *node;
 296
 297         qsort(events_array, cnt, sizeof(struct event_node), compar);
 298
 299         for (pos = 0; pos < cnt; pos++) {
 300                 ret = process_event(evlist, events_array[pos].event,
 301                                     switch_tracking);
 302                 if (ret < 0)
 303                         goto out_free;
 304         }
 305
 306         ret = 0;
 307 out_free:
 308         pr_debug("%u events recorded\n", cnt);
 309         free(events_array);
 310 out_free_nodes:
 311         free_event_nodes(&events);
 312         return ret;
 313 }
 314
 315 /**
 316  * test__switch_tracking - test using sched_switch and tracking events.
 317  *
 318  * This function implements a test that checks that sched_switch events and
 319  * tracking events can be recorded for a workload (current process) using the
 320  * evsel->core.system_wide and evsel->tracking flags (respectively) with other events
 321  * sometimes enabled or disabled.
 322  */
 323 int test__switch_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
 324 {
 325         const char *sched_switch = "sched:sched_switch";
 326         struct switch_tracking switch_tracking = { .tids = NULL, };
 327         struct record_opts opts = {
 328                 .mmap_pages          = UINT_MAX,
 329                 .user_freq           = UINT_MAX,
 330                 .user_interval       = ULLONG_MAX,
 331                 .freq                = 4000,
 332                 .target              = {
 333                         .uses_mmap   = true,
 334                 },
 335         };
 336         struct perf_thread_map *threads = NULL;
 337         struct perf_cpu_map *cpus = NULL;
 338         struct evlist *evlist = NULL;
 339         struct evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
 340         struct evsel *switch_evsel, *tracking_evsel;
 341         const char *comm;
 342         int err = -1;
 343
 344         threads = thread_map__new(-1, getpid(), UINT_MAX);
 345         if (!threads) {
 346                 pr_debug("thread_map__new failed!\n");
 347                 goto out_err;
 348         }
 349
 350         cpus = perf_cpu_map__new(NULL);
 351         if (!cpus) {
 352                 pr_debug("perf_cpu_map__new failed!\n");
 353                 goto out_err;
 354         }
 355
 356         evlist = evlist__new();
 357         if (!evlist) {
 358                 pr_debug("evlist__new failed!\n");
 359                 goto out_err;
 360         }
 361
 362         perf_evlist__set_maps(&evlist->core, cpus, threads);
 363
 364         /* First event */
 365         err = parse_events(evlist, "cpu-clock:u", NULL);
 366         if (err) {
 367                 pr_debug("Failed to parse event dummy:u\n");
 368                 goto out_err;
 369         }
 370
 371         cpu_clocks_evsel = evlist__last(evlist);
 372
 373         /* Second event */
 374         err = parse_events(evlist, "cycles:u", NULL);
 375         if (err) {
 376                 pr_debug("Failed to parse event cycles:u\n");
 377                 goto out_err;
 378         }
 379
 380         cycles_evsel = evlist__last(evlist);
 381
 382         /* Third event */
 383         if (!perf_evlist__can_select_event(evlist, sched_switch)) {
 384                 pr_debug("No sched_switch\n");
 385                 err = 0;
 386                 goto out;
 387         }
 388
 389         err = parse_events(evlist, sched_switch, NULL);
 390         if (err) {
 391                 pr_debug("Failed to parse event %s\n", sched_switch);
 392                 goto out_err;
 393         }
 394
 395         switch_evsel = evlist__last(evlist);
 396
 397         evsel__set_sample_bit(switch_evsel, CPU);
 398         evsel__set_sample_bit(switch_evsel, TIME);
 399
 400         switch_evsel->core.system_wide = true;
 401         switch_evsel->no_aux_samples = true;
 402         switch_evsel->immediate = true;
 403
 404         /* Test moving an event to the front */
 405         if (cycles_evsel == evlist__first(evlist)) {
 406                 pr_debug("cycles event already at front");
 407                 goto out_err;
 408         }
 409         perf_evlist__to_front(evlist, cycles_evsel);
 410         if (cycles_evsel != evlist__first(evlist)) {
 411                 pr_debug("Failed to move cycles event to front");
 412                 goto out_err;
 413         }
 414
 415         evsel__set_sample_bit(cycles_evsel, CPU);
 416         evsel__set_sample_bit(cycles_evsel, TIME);
 417
 418         /* Fourth event */
 419         err = parse_events(evlist, "dummy:u", NULL);
 420         if (err) {
 421                 pr_debug("Failed to parse event dummy:u\n");
 422                 goto out_err;
 423         }
 424
 425         tracking_evsel = evlist__last(evlist);
 426
 427         perf_evlist__set_tracking_event(evlist, tracking_evsel);
 428
 429         tracking_evsel->core.attr.freq = 0;
 430         tracking_evsel->core.attr.sample_period = 1;
 431
 432         evsel__set_sample_bit(tracking_evsel, TIME);
 433
 434         /* Config events */
 435         perf_evlist__config(evlist, &opts, NULL);
 436
 437         /* Check moved event is still at the front */
 438         if (cycles_evsel != evlist__first(evlist)) {
 439                 pr_debug("Front event no longer at front");
 440                 goto out_err;
 441         }
 442
 443         /* Check tracking event is tracking */
 444         if (!tracking_evsel->core.attr.mmap || !tracking_evsel->core.attr.comm) {
 445                 pr_debug("Tracking event not tracking\n");
 446                 goto out_err;
 447         }
 448
 449         /* Check non-tracking events are not tracking */
 450         evlist__for_each_entry(evlist, evsel) {
 451                 if (evsel != tracking_evsel) {
 452                         if (evsel->core.attr.mmap || evsel->core.attr.comm) {
 453                                 pr_debug("Non-tracking event is tracking\n");
 454                                 goto out_err;
 455                         }
 456                 }
 457         }
 458
 459         if (evlist__open(evlist) < 0) {
 460                 pr_debug("Not supported\n");
 461                 err = 0;
 462                 goto out;
 463         }
 464
 465         err = evlist__mmap(evlist, UINT_MAX);
 466         if (err) {
 467                 pr_debug("evlist__mmap failed!\n");
 468                 goto out_err;
 469         }
 470
 471         evlist__enable(evlist);
 472
 473         err = evsel__disable(cpu_clocks_evsel);
 474         if (err) {
 475                 pr_debug("perf_evlist__disable_event failed!\n");
 476                 goto out_err;
 477         }
 478
 479         err = spin_sleep();
 480         if (err) {
 481                 pr_debug("spin_sleep failed!\n");
 482                 goto out_err;
 483         }
 484
 485         comm = "Test COMM 1";
 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 = evsel__disable(cycles_evsel);
 493         if (err) {
 494                 pr_debug("perf_evlist__disable_event failed!\n");
 495                 goto out_err;
 496         }
 497
 498         comm = "Test COMM 2";
 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 = spin_sleep();
 506         if (err) {
 507                 pr_debug("spin_sleep failed!\n");
 508                 goto out_err;
 509         }
 510
 511         comm = "Test COMM 3";
 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 = evsel__enable(cycles_evsel);
 519         if (err) {
 520                 pr_debug("perf_evlist__disable_event failed!\n");
 521                 goto out_err;
 522         }
 523
 524         comm = "Test COMM 4";
 525         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 526         if (err) {
 527                 pr_debug("PR_SET_NAME failed!\n");
 528                 goto out_err;
 529         }
 530
 531         err = spin_sleep();
 532         if (err) {
 533                 pr_debug("spin_sleep failed!\n");
 534                 goto out_err;
 535         }
 536
 537         evlist__disable(evlist);
 538
 539         switch_tracking.switch_evsel = switch_evsel;
 540         switch_tracking.cycles_evsel = cycles_evsel;
 541
 542         err = process_events(evlist, &switch_tracking);
 543
 544         zfree(&switch_tracking.tids);
 545
 546         if (err)
 547                 goto out_err;
 548
 549         /* Check all 4 comm events were seen i.e. that evsel->tracking works */
 550         if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
 551             !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
 552                 pr_debug("Missing comm events\n");
 553                 goto out_err;
 554         }
 555
 556         /* Check cycles event got enabled */
 557         if (!switch_tracking.cycles_before_comm_1) {
 558                 pr_debug("Missing cycles events\n");
 559                 goto out_err;
 560         }
 561
 562         /* Check cycles event got disabled */
 563         if (switch_tracking.cycles_between_comm_2_and_comm_3) {
 564                 pr_debug("cycles events even though event was disabled\n");
 565                 goto out_err;
 566         }
 567
 568         /* Check cycles event got enabled again */
 569         if (!switch_tracking.cycles_after_comm_4) {
 570                 pr_debug("Missing cycles events\n");
 571                 goto out_err;
 572         }
 573 out:
 574         if (evlist) {
 575                 evlist__disable(evlist);
 576                 evlist__delete(evlist);
 577         } else {
 578                 perf_cpu_map__put(cpus);
 579                 perf_thread_map__put(threads);
 580         }
 581
 582         return err;
 583
 584 out_err:
 585         err = -1;
 586         goto out;
 587 }