tools/perf/tests/switch-tracking.c

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