tools/perf/tests/switch-tracking.c

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