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 #include <linux/zalloc.h>
   8
   9 #include "parse-events.h"
  10 #include "evlist.h"
  11 #include "evsel.h"
  12 #include "thread_map.h"
  13 #include "cpumap.h"
  14 #include "tests.h"
  15
  16 static int spin_sleep(void)
  17 {
  18         struct timeval start, now, diff, maxtime;
  19         struct timespec ts;
  20         int err, i;
  21
  22         maxtime.tv_sec = 0;
  23         maxtime.tv_usec = 50000;
  24
  25         err = gettimeofday(&start, NULL);
  26         if (err)
  27                 return err;
  28
  29         /* Spin for 50ms */
  30         while (1) {
  31                 for (i = 0; i < 1000; i++)
  32                         barrier();
  33
  34                 err = gettimeofday(&now, NULL);
  35                 if (err)
  36                         return err;
  37
  38                 timersub(&now, &start, &diff);
  39                 if (timercmp(&diff, &maxtime, > /* For checkpatch */))
  40                         break;
  41         }
  42
  43         ts.tv_nsec = 50 * 1000 * 1000;
  44         ts.tv_sec = 0;
  45
  46         /* Sleep for 50ms */
  47         err = nanosleep(&ts, NULL);
  48         if (err == EINTR)
  49                 err = 0;
  50
  51         return err;
  52 }
  53
  54 struct switch_tracking {
  55         struct perf_evsel *switch_evsel;
  56         struct perf_evsel *cycles_evsel;
  57         pid_t *tids;
  58         int nr_tids;
  59         int comm_seen[4];
  60         int cycles_before_comm_1;
  61         int cycles_between_comm_2_and_comm_3;
  62         int cycles_after_comm_4;
  63 };
  64
  65 static int check_comm(struct switch_tracking *switch_tracking,
  66                       union perf_event *event, const char *comm, int nr)
  67 {
  68         if (event->header.type == PERF_RECORD_COMM &&
  69             (pid_t)event->comm.pid == getpid() &&
  70             (pid_t)event->comm.tid == getpid() &&
  71             strcmp(event->comm.comm, comm) == 0) {
  72                 if (switch_tracking->comm_seen[nr]) {
  73                         pr_debug("Duplicate comm event\n");
  74                         return -1;
  75                 }
  76                 switch_tracking->comm_seen[nr] = 1;
  77                 pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
  78                 return 1;
  79         }
  80         return 0;
  81 }
  82
  83 static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
  84 {
  85         int i, nr = cpu + 1;
  86
  87         if (cpu < 0)
  88                 return -1;
  89
  90         if (!switch_tracking->tids) {
  91                 switch_tracking->tids = calloc(nr, sizeof(pid_t));
  92                 if (!switch_tracking->tids)
  93                         return -1;
  94                 for (i = 0; i < nr; i++)
  95                         switch_tracking->tids[i] = -1;
  96                 switch_tracking->nr_tids = nr;
  97                 return 0;
  98         }
  99
 100         if (cpu >= switch_tracking->nr_tids) {
 101                 void *addr;
 102
 103                 addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
 104                 if (!addr)
 105                         return -1;
 106                 switch_tracking->tids = addr;
 107                 for (i = switch_tracking->nr_tids; i < nr; i++)
 108                         switch_tracking->tids[i] = -1;
 109                 switch_tracking->nr_tids = nr;
 110                 return 0;
 111         }
 112
 113         return 0;
 114 }
 115
 116 static int process_sample_event(struct perf_evlist *evlist,
 117                                 union perf_event *event,
 118                                 struct switch_tracking *switch_tracking)
 119 {
 120         struct perf_sample sample;
 121         struct perf_evsel *evsel;
 122         pid_t next_tid, prev_tid;
 123         int cpu, err;
 124
 125         if (perf_evlist__parse_sample(evlist, event, &sample)) {
 126                 pr_debug("perf_evlist__parse_sample failed\n");
 127                 return -1;
 128         }
 129
 130         evsel = perf_evlist__id2evsel(evlist, sample.id);
 131         if (evsel == switch_tracking->switch_evsel) {
 132                 next_tid = perf_evsel__intval(evsel, &sample, "next_pid");
 133                 prev_tid = perf_evsel__intval(evsel, &sample, "prev_pid");
 134                 cpu = sample.cpu;
 135                 pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
 136                           cpu, prev_tid, next_tid);
 137                 err = check_cpu(switch_tracking, cpu);
 138                 if (err)
 139                         return err;
 140                 /*
 141                  * Check for no missing sched_switch events i.e. that the
 142                  * evsel->system_wide flag has worked.
 143                  */
 144                 if (switch_tracking->tids[cpu] != -1 &&
 145                     switch_tracking->tids[cpu] != prev_tid) {
 146                         pr_debug("Missing sched_switch events\n");
 147                         return -1;
 148                 }
 149                 switch_tracking->tids[cpu] = next_tid;
 150         }
 151
 152         if (evsel == switch_tracking->cycles_evsel) {
 153                 pr_debug3("cycles event\n");
 154                 if (!switch_tracking->comm_seen[0])
 155                         switch_tracking->cycles_before_comm_1 = 1;
 156                 if (switch_tracking->comm_seen[1] &&
 157                     !switch_tracking->comm_seen[2])
 158                         switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
 159                 if (switch_tracking->comm_seen[3])
 160                         switch_tracking->cycles_after_comm_4 = 1;
 161         }
 162
 163         return 0;
 164 }
 165
 166 static int process_event(struct perf_evlist *evlist, union perf_event *event,
 167                          struct switch_tracking *switch_tracking)
 168 {
 169         if (event->header.type == PERF_RECORD_SAMPLE)
 170                 return process_sample_event(evlist, event, switch_tracking);
 171
 172         if (event->header.type == PERF_RECORD_COMM) {
 173                 int err, done = 0;
 174
 175                 err = check_comm(switch_tracking, event, "Test COMM 1", 0);
 176                 if (err < 0)
 177                         return -1;
 178                 done += err;
 179                 err = check_comm(switch_tracking, event, "Test COMM 2", 1);
 180                 if (err < 0)
 181                         return -1;
 182                 done += err;
 183                 err = check_comm(switch_tracking, event, "Test COMM 3", 2);
 184                 if (err < 0)
 185                         return -1;
 186                 done += err;
 187                 err = check_comm(switch_tracking, event, "Test COMM 4", 3);
 188                 if (err < 0)
 189                         return -1;
 190                 done += err;
 191                 if (done != 1) {
 192                         pr_debug("Unexpected comm event\n");
 193                         return -1;
 194                 }
 195         }
 196
 197         return 0;
 198 }
 199
 200 struct event_node {
 201         struct list_head list;
 202         union perf_event *event;
 203         u64 event_time;
 204 };
 205
 206 static int add_event(struct perf_evlist *evlist, struct list_head *events,
 207                      union perf_event *event)
 208 {
 209         struct perf_sample sample;
 210         struct event_node *node;
 211
 212         node = malloc(sizeof(struct event_node));
 213         if (!node) {
 214                 pr_debug("malloc failed\n");
 215                 return -1;
 216         }
 217         node->event = event;
 218         list_add(&node->list, events);
 219
 220         if (perf_evlist__parse_sample(evlist, event, &sample)) {
 221                 pr_debug("perf_evlist__parse_sample failed\n");
 222                 return -1;
 223         }
 224
 225         if (!sample.time) {
 226                 pr_debug("event with no time\n");
 227                 return -1;
 228         }
 229
 230         node->event_time = sample.time;
 231
 232         return 0;
 233 }
 234
 235 static void free_event_nodes(struct list_head *events)
 236 {
 237         struct event_node *node;
 238
 239         while (!list_empty(events)) {
 240                 node = list_entry(events->next, struct event_node, list);
 241                 list_del_init(&node->list);
 242                 free(node);
 243         }
 244 }
 245
 246 static int compar(const void *a, const void *b)
 247 {
 248         const struct event_node *nodea = a;
 249         const struct event_node *nodeb = b;
 250         s64 cmp = nodea->event_time - nodeb->event_time;
 251
 252         return cmp;
 253 }
 254
 255 static int process_events(struct perf_evlist *evlist,
 256                           struct switch_tracking *switch_tracking)
 257 {
 258         union perf_event *event;
 259         unsigned pos, cnt = 0;
 260         LIST_HEAD(events);
 261         struct event_node *events_array, *node;
 262         struct perf_mmap *md;
 263         int i, ret;
 264
 265         for (i = 0; i < evlist->nr_mmaps; i++) {
 266                 md = &evlist->mmap[i];
 267                 if (perf_mmap__read_init(md) < 0)
 268                         continue;
 269
 270                 while ((event = perf_mmap__read_event(md)) != NULL) {
 271                         cnt += 1;
 272                         ret = add_event(evlist, &events, event);
 273                          perf_mmap__consume(md);
 274                         if (ret < 0)
 275                                 goto out_free_nodes;
 276                 }
 277                 perf_mmap__read_done(md);
 278         }
 279
 280         events_array = calloc(cnt, sizeof(struct event_node));
 281         if (!events_array) {
 282                 pr_debug("calloc failed\n");
 283                 ret = -1;
 284                 goto out_free_nodes;
 285         }
 286
 287         pos = 0;
 288         list_for_each_entry(node, &events, list)
 289                 events_array[pos++] = *node;
 290
 291         qsort(events_array, cnt, sizeof(struct event_node), compar);
 292
 293         for (pos = 0; pos < cnt; pos++) {
 294                 ret = process_event(evlist, events_array[pos].event,
 295                                     switch_tracking);
 296                 if (ret < 0)
 297                         goto out_free;
 298         }
 299
 300         ret = 0;
 301 out_free:
 302         pr_debug("%u events recorded\n", cnt);
 303         free(events_array);
 304 out_free_nodes:
 305         free_event_nodes(&events);
 306         return ret;
 307 }
 308
 309 /**
 310  * test__switch_tracking - test using sched_switch and tracking events.
 311  *
 312  * This function implements a test that checks that sched_switch events and
 313  * tracking events can be recorded for a workload (current process) using the
 314  * evsel->system_wide and evsel->tracking flags (respectively) with other events
 315  * sometimes enabled or disabled.
 316  */
 317 int test__switch_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
 318 {
 319         const char *sched_switch = "sched:sched_switch";
 320         struct switch_tracking switch_tracking = { .tids = NULL, };
 321         struct record_opts opts = {
 322                 .mmap_pages          = UINT_MAX,
 323                 .user_freq           = UINT_MAX,
 324                 .user_interval       = ULLONG_MAX,
 325                 .freq                = 4000,
 326                 .target              = {
 327                         .uses_mmap   = true,
 328                 },
 329         };
 330         struct thread_map *threads = NULL;
 331         struct cpu_map *cpus = NULL;
 332         struct perf_evlist *evlist = NULL;
 333         struct perf_evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
 334         struct perf_evsel *switch_evsel, *tracking_evsel;
 335         const char *comm;
 336         int err = -1;
 337
 338         threads = thread_map__new(-1, getpid(), UINT_MAX);
 339         if (!threads) {
 340                 pr_debug("thread_map__new failed!\n");
 341                 goto out_err;
 342         }
 343
 344         cpus = cpu_map__new(NULL);
 345         if (!cpus) {
 346                 pr_debug("cpu_map__new failed!\n");
 347                 goto out_err;
 348         }
 349
 350         evlist = perf_evlist__new();
 351         if (!evlist) {
 352                 pr_debug("perf_evlist__new failed!\n");
 353                 goto out_err;
 354         }
 355
 356         perf_evlist__set_maps(evlist, cpus, threads);
 357
 358         /* First event */
 359         err = parse_events(evlist, "cpu-clock:u", NULL);
 360         if (err) {
 361                 pr_debug("Failed to parse event dummy:u\n");
 362                 goto out_err;
 363         }
 364
 365         cpu_clocks_evsel = perf_evlist__last(evlist);
 366
 367         /* Second event */
 368         err = parse_events(evlist, "cycles:u", NULL);
 369         if (err) {
 370                 pr_debug("Failed to parse event cycles:u\n");
 371                 goto out_err;
 372         }
 373
 374         cycles_evsel = perf_evlist__last(evlist);
 375
 376         /* Third event */
 377         if (!perf_evlist__can_select_event(evlist, sched_switch)) {
 378                 pr_debug("No sched_switch\n");
 379                 err = 0;
 380                 goto out;
 381         }
 382
 383         err = parse_events(evlist, sched_switch, NULL);
 384         if (err) {
 385                 pr_debug("Failed to parse event %s\n", sched_switch);
 386                 goto out_err;
 387         }
 388
 389         switch_evsel = perf_evlist__last(evlist);
 390
 391         perf_evsel__set_sample_bit(switch_evsel, CPU);
 392         perf_evsel__set_sample_bit(switch_evsel, TIME);
 393
 394         switch_evsel->system_wide = true;
 395         switch_evsel->no_aux_samples = true;
 396         switch_evsel->immediate = true;
 397
 398         /* Test moving an event to the front */
 399         if (cycles_evsel == perf_evlist__first(evlist)) {
 400                 pr_debug("cycles event already at front");
 401                 goto out_err;
 402         }
 403         perf_evlist__to_front(evlist, cycles_evsel);
 404         if (cycles_evsel != perf_evlist__first(evlist)) {
 405                 pr_debug("Failed to move cycles event to front");
 406                 goto out_err;
 407         }
 408
 409         perf_evsel__set_sample_bit(cycles_evsel, CPU);
 410         perf_evsel__set_sample_bit(cycles_evsel, TIME);
 411
 412         /* Fourth event */
 413         err = parse_events(evlist, "dummy:u", NULL);
 414         if (err) {
 415                 pr_debug("Failed to parse event dummy:u\n");
 416                 goto out_err;
 417         }
 418
 419         tracking_evsel = perf_evlist__last(evlist);
 420
 421         perf_evlist__set_tracking_event(evlist, tracking_evsel);
 422
 423         tracking_evsel->attr.freq = 0;
 424         tracking_evsel->attr.sample_period = 1;
 425
 426         perf_evsel__set_sample_bit(tracking_evsel, TIME);
 427
 428         /* Config events */
 429         perf_evlist__config(evlist, &opts, NULL);
 430
 431         /* Check moved event is still at the front */
 432         if (cycles_evsel != perf_evlist__first(evlist)) {
 433                 pr_debug("Front event no longer at front");
 434                 goto out_err;
 435         }
 436
 437         /* Check tracking event is tracking */
 438         if (!tracking_evsel->attr.mmap || !tracking_evsel->attr.comm) {
 439                 pr_debug("Tracking event not tracking\n");
 440                 goto out_err;
 441         }
 442
 443         /* Check non-tracking events are not tracking */
 444         evlist__for_each_entry(evlist, evsel) {
 445                 if (evsel != tracking_evsel) {
 446                         if (evsel->attr.mmap || evsel->attr.comm) {
 447                                 pr_debug("Non-tracking event is tracking\n");
 448                                 goto out_err;
 449                         }
 450                 }
 451         }
 452
 453         if (perf_evlist__open(evlist) < 0) {
 454                 pr_debug("Not supported\n");
 455                 err = 0;
 456                 goto out;
 457         }
 458
 459         err = perf_evlist__mmap(evlist, UINT_MAX);
 460         if (err) {
 461                 pr_debug("perf_evlist__mmap failed!\n");
 462                 goto out_err;
 463         }
 464
 465         perf_evlist__enable(evlist);
 466
 467         err = perf_evsel__disable(cpu_clocks_evsel);
 468         if (err) {
 469                 pr_debug("perf_evlist__disable_event failed!\n");
 470                 goto out_err;
 471         }
 472
 473         err = spin_sleep();
 474         if (err) {
 475                 pr_debug("spin_sleep failed!\n");
 476                 goto out_err;
 477         }
 478
 479         comm = "Test COMM 1";
 480         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 481         if (err) {
 482                 pr_debug("PR_SET_NAME failed!\n");
 483                 goto out_err;
 484         }
 485
 486         err = perf_evsel__disable(cycles_evsel);
 487         if (err) {
 488                 pr_debug("perf_evlist__disable_event failed!\n");
 489                 goto out_err;
 490         }
 491
 492         comm = "Test COMM 2";
 493         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 494         if (err) {
 495                 pr_debug("PR_SET_NAME failed!\n");
 496                 goto out_err;
 497         }
 498
 499         err = spin_sleep();
 500         if (err) {
 501                 pr_debug("spin_sleep failed!\n");
 502                 goto out_err;
 503         }
 504
 505         comm = "Test COMM 3";
 506         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 507         if (err) {
 508                 pr_debug("PR_SET_NAME failed!\n");
 509                 goto out_err;
 510         }
 511
 512         err = perf_evsel__enable(cycles_evsel);
 513         if (err) {
 514                 pr_debug("perf_evlist__disable_event failed!\n");
 515                 goto out_err;
 516         }
 517
 518         comm = "Test COMM 4";
 519         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 520         if (err) {
 521                 pr_debug("PR_SET_NAME failed!\n");
 522                 goto out_err;
 523         }
 524
 525         err = spin_sleep();
 526         if (err) {
 527                 pr_debug("spin_sleep failed!\n");
 528                 goto out_err;
 529         }
 530
 531         perf_evlist__disable(evlist);
 532
 533         switch_tracking.switch_evsel = switch_evsel;
 534         switch_tracking.cycles_evsel = cycles_evsel;
 535
 536         err = process_events(evlist, &switch_tracking);
 537
 538         zfree(&switch_tracking.tids);
 539
 540         if (err)
 541                 goto out_err;
 542
 543         /* Check all 4 comm events were seen i.e. that evsel->tracking works */
 544         if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
 545             !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
 546                 pr_debug("Missing comm events\n");
 547                 goto out_err;
 548         }
 549
 550         /* Check cycles event got enabled */
 551         if (!switch_tracking.cycles_before_comm_1) {
 552                 pr_debug("Missing cycles events\n");
 553                 goto out_err;
 554         }
 555
 556         /* Check cycles event got disabled */
 557         if (switch_tracking.cycles_between_comm_2_and_comm_3) {
 558                 pr_debug("cycles events even though event was disabled\n");
 559                 goto out_err;
 560         }
 561
 562         /* Check cycles event got enabled again */
 563         if (!switch_tracking.cycles_after_comm_4) {
 564                 pr_debug("Missing cycles events\n");
 565                 goto out_err;
 566         }
 567 out:
 568         if (evlist) {
 569                 perf_evlist__disable(evlist);
 570                 perf_evlist__delete(evlist);
 571         } else {
 572                 cpu_map__put(cpus);
 573                 thread_map__put(threads);
 574         }
 575
 576         return err;
 577
 578 out_err:
 579         err = -1;
 580         goto out;
 581 }