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
  12 #include "debug.h"
  13 #include "parse-events.h"
  14 #include "evlist.h"
  15 #include "evsel.h"
  16 #include "thread_map.h"
  17 #include "record.h"
  18 #include "tests.h"
  19
  20 static int spin_sleep(void)
  21 {
  22         struct timeval start, now, diff, maxtime;
  23         struct timespec ts;
  24         int err, i;
  25
  26         maxtime.tv_sec = 0;
  27         maxtime.tv_usec = 50000;
  28
  29         err = gettimeofday(&start, NULL);
  30         if (err)
  31                 return err;
  32
  33         /* Spin for 50ms */
  34         while (1) {
  35                 for (i = 0; i < 1000; i++)
  36                         barrier();
  37
  38                 err = gettimeofday(&now, NULL);
  39                 if (err)
  40                         return err;
  41
  42                 timersub(&now, &start, &diff);
  43                 if (timercmp(&diff, &maxtime, > /* For checkpatch */))
  44                         break;
  45         }
  46
  47         ts.tv_nsec = 50 * 1000 * 1000;
  48         ts.tv_sec = 0;
  49
  50         /* Sleep for 50ms */
  51         err = nanosleep(&ts, NULL);
  52         if (err == EINTR)
  53                 err = 0;
  54
  55         return err;
  56 }
  57
  58 struct switch_tracking {
  59         struct evsel *switch_evsel;
  60         struct evsel *cycles_evsel;
  61         pid_t *tids;
  62         int nr_tids;
  63         int comm_seen[4];
  64         int cycles_before_comm_1;
  65         int cycles_between_comm_2_and_comm_3;
  66         int cycles_after_comm_4;
  67 };
  68
  69 static int check_comm(struct switch_tracking *switch_tracking,
  70                       union perf_event *event, const char *comm, int nr)
  71 {
  72         if (event->header.type == PERF_RECORD_COMM &&
  73             (pid_t)event->comm.pid == getpid() &&
  74             (pid_t)event->comm.tid == getpid() &&
  75             strcmp(event->comm.comm, comm) == 0) {
  76                 if (switch_tracking->comm_seen[nr]) {
  77                         pr_debug("Duplicate comm event\n");
  78                         return -1;
  79                 }
  80                 switch_tracking->comm_seen[nr] = 1;
  81                 pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
  82                 return 1;
  83         }
  84         return 0;
  85 }
  86
  87 static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
  88 {
  89         int i, nr = cpu + 1;
  90
  91         if (cpu < 0)
  92                 return -1;
  93
  94         if (!switch_tracking->tids) {
  95                 switch_tracking->tids = calloc(nr, sizeof(pid_t));
  96                 if (!switch_tracking->tids)
  97                         return -1;
  98                 for (i = 0; i < nr; i++)
  99                         switch_tracking->tids[i] = -1;
 100                 switch_tracking->nr_tids = nr;
 101                 return 0;
 102         }
 103
 104         if (cpu >= switch_tracking->nr_tids) {
 105                 void *addr;
 106
 107                 addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
 108                 if (!addr)
 109                         return -1;
 110                 switch_tracking->tids = addr;
 111                 for (i = switch_tracking->nr_tids; i < nr; i++)
 112                         switch_tracking->tids[i] = -1;
 113                 switch_tracking->nr_tids = nr;
 114                 return 0;
 115         }
 116
 117         return 0;
 118 }
 119
 120 static int process_sample_event(struct evlist *evlist,
 121                                 union perf_event *event,
 122                                 struct switch_tracking *switch_tracking)
 123 {
 124         struct perf_sample sample;
 125         struct evsel *evsel;
 126         pid_t next_tid, prev_tid;
 127         int cpu, err;
 128
 129         if (perf_evlist__parse_sample(evlist, event, &sample)) {
 130                 pr_debug("perf_evlist__parse_sample failed\n");
 131                 return -1;
 132         }
 133
 134         evsel = perf_evlist__id2evsel(evlist, sample.id);
 135         if (evsel == switch_tracking->switch_evsel) {
 136                 next_tid = perf_evsel__intval(evsel, &sample, "next_pid");
 137                 prev_tid = perf_evsel__intval(evsel, &sample, "prev_pid");
 138                 cpu = sample.cpu;
 139                 pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
 140                           cpu, prev_tid, next_tid);
 141                 err = check_cpu(switch_tracking, cpu);
 142                 if (err)
 143                         return err;
 144                 /*
 145                  * Check for no missing sched_switch events i.e. that the
 146                  * evsel->system_wide flag has worked.
 147                  */
 148                 if (switch_tracking->tids[cpu] != -1 &&
 149                     switch_tracking->tids[cpu] != prev_tid) {
 150                         pr_debug("Missing sched_switch events\n");
 151                         return -1;
 152                 }
 153                 switch_tracking->tids[cpu] = next_tid;
 154         }
 155
 156         if (evsel == switch_tracking->cycles_evsel) {
 157                 pr_debug3("cycles event\n");
 158                 if (!switch_tracking->comm_seen[0])
 159                         switch_tracking->cycles_before_comm_1 = 1;
 160                 if (switch_tracking->comm_seen[1] &&
 161                     !switch_tracking->comm_seen[2])
 162                         switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
 163                 if (switch_tracking->comm_seen[3])
 164                         switch_tracking->cycles_after_comm_4 = 1;
 165         }
 166
 167         return 0;
 168 }
 169
 170 static int process_event(struct evlist *evlist, union perf_event *event,
 171                          struct switch_tracking *switch_tracking)
 172 {
 173         if (event->header.type == PERF_RECORD_SAMPLE)
 174                 return process_sample_event(evlist, event, switch_tracking);
 175
 176         if (event->header.type == PERF_RECORD_COMM) {
 177                 int err, done = 0;
 178
 179                 err = check_comm(switch_tracking, event, "Test COMM 1", 0);
 180                 if (err < 0)
 181                         return -1;
 182                 done += err;
 183                 err = check_comm(switch_tracking, event, "Test COMM 2", 1);
 184                 if (err < 0)
 185                         return -1;
 186                 done += err;
 187                 err = check_comm(switch_tracking, event, "Test COMM 3", 2);
 188                 if (err < 0)
 189                         return -1;
 190                 done += err;
 191                 err = check_comm(switch_tracking, event, "Test COMM 4", 3);
 192                 if (err < 0)
 193                         return -1;
 194                 done += err;
 195                 if (done != 1) {
 196                         pr_debug("Unexpected comm event\n");
 197                         return -1;
 198                 }
 199         }
 200
 201         return 0;
 202 }
 203
 204 struct event_node {
 205         struct list_head list;
 206         union perf_event *event;
 207         u64 event_time;
 208 };
 209
 210 static int add_event(struct evlist *evlist, struct list_head *events,
 211                      union perf_event *event)
 212 {
 213         struct perf_sample sample;
 214         struct event_node *node;
 215
 216         node = malloc(sizeof(struct event_node));
 217         if (!node) {
 218                 pr_debug("malloc failed\n");
 219                 return -1;
 220         }
 221         node->event = event;
 222         list_add(&node->list, events);
 223
 224         if (perf_evlist__parse_sample(evlist, event, &sample)) {
 225                 pr_debug("perf_evlist__parse_sample failed\n");
 226                 return -1;
 227         }
 228
 229         if (!sample.time) {
 230                 pr_debug("event with no time\n");
 231                 return -1;
 232         }
 233
 234         node->event_time = sample.time;
 235
 236         return 0;
 237 }
 238
 239 static void free_event_nodes(struct list_head *events)
 240 {
 241         struct event_node *node;
 242
 243         while (!list_empty(events)) {
 244                 node = list_entry(events->next, struct event_node, list);
 245                 list_del_init(&node->list);
 246                 free(node);
 247         }
 248 }
 249
 250 static int compar(const void *a, const void *b)
 251 {
 252         const struct event_node *nodea = a;
 253         const struct event_node *nodeb = b;
 254         s64 cmp = nodea->event_time - nodeb->event_time;
 255
 256         return cmp;
 257 }
 258
 259 static int process_events(struct evlist *evlist,
 260                           struct switch_tracking *switch_tracking)
 261 {
 262         union perf_event *event;
 263         unsigned pos, cnt = 0;
 264         LIST_HEAD(events);
 265         struct event_node *events_array, *node;
 266         struct mmap *md;
 267         int i, ret;
 268
 269         for (i = 0; i < evlist->nr_mmaps; i++) {
 270                 md = &evlist->mmap[i];
 271                 if (perf_mmap__read_init(md) < 0)
 272                         continue;
 273
 274                 while ((event = perf_mmap__read_event(md)) != NULL) {
 275                         cnt += 1;
 276                         ret = add_event(evlist, &events, event);
 277                          perf_mmap__consume(md);
 278                         if (ret < 0)
 279                                 goto out_free_nodes;
 280                 }
 281                 perf_mmap__read_done(md);
 282         }
 283
 284         events_array = calloc(cnt, sizeof(struct event_node));
 285         if (!events_array) {
 286                 pr_debug("calloc failed\n");
 287                 ret = -1;
 288                 goto out_free_nodes;
 289         }
 290
 291         pos = 0;
 292         list_for_each_entry(node, &events, list)
 293                 events_array[pos++] = *node;
 294
 295         qsort(events_array, cnt, sizeof(struct event_node), compar);
 296
 297         for (pos = 0; pos < cnt; pos++) {
 298                 ret = process_event(evlist, events_array[pos].event,
 299                                     switch_tracking);
 300                 if (ret < 0)
 301                         goto out_free;
 302         }
 303
 304         ret = 0;
 305 out_free:
 306         pr_debug("%u events recorded\n", cnt);
 307         free(events_array);
 308 out_free_nodes:
 309         free_event_nodes(&events);
 310         return ret;
 311 }
 312
 313 /**
 314  * test__switch_tracking - test using sched_switch and tracking events.
 315  *
 316  * This function implements a test that checks that sched_switch events and
 317  * tracking events can be recorded for a workload (current process) using the
 318  * evsel->system_wide and evsel->tracking flags (respectively) with other events
 319  * sometimes enabled or disabled.
 320  */
 321 int test__switch_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
 322 {
 323         const char *sched_switch = "sched:sched_switch";
 324         struct switch_tracking switch_tracking = { .tids = NULL, };
 325         struct record_opts opts = {
 326                 .mmap_pages          = UINT_MAX,
 327                 .user_freq           = UINT_MAX,
 328                 .user_interval       = ULLONG_MAX,
 329                 .freq                = 4000,
 330                 .target              = {
 331                         .uses_mmap   = true,
 332                 },
 333         };
 334         struct perf_thread_map *threads = NULL;
 335         struct perf_cpu_map *cpus = NULL;
 336         struct evlist *evlist = NULL;
 337         struct evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
 338         struct evsel *switch_evsel, *tracking_evsel;
 339         const char *comm;
 340         int err = -1;
 341
 342         threads = thread_map__new(-1, getpid(), UINT_MAX);
 343         if (!threads) {
 344                 pr_debug("thread_map__new failed!\n");
 345                 goto out_err;
 346         }
 347
 348         cpus = perf_cpu_map__new(NULL);
 349         if (!cpus) {
 350                 pr_debug("perf_cpu_map__new failed!\n");
 351                 goto out_err;
 352         }
 353
 354         evlist = evlist__new();
 355         if (!evlist) {
 356                 pr_debug("evlist__new failed!\n");
 357                 goto out_err;
 358         }
 359
 360         perf_evlist__set_maps(&evlist->core, cpus, threads);
 361
 362         /* First event */
 363         err = parse_events(evlist, "cpu-clock:u", NULL);
 364         if (err) {
 365                 pr_debug("Failed to parse event dummy:u\n");
 366                 goto out_err;
 367         }
 368
 369         cpu_clocks_evsel = perf_evlist__last(evlist);
 370
 371         /* Second event */
 372         err = parse_events(evlist, "cycles:u", NULL);
 373         if (err) {
 374                 pr_debug("Failed to parse event cycles:u\n");
 375                 goto out_err;
 376         }
 377
 378         cycles_evsel = perf_evlist__last(evlist);
 379
 380         /* Third event */
 381         if (!perf_evlist__can_select_event(evlist, sched_switch)) {
 382                 pr_debug("No sched_switch\n");
 383                 err = 0;
 384                 goto out;
 385         }
 386
 387         err = parse_events(evlist, sched_switch, NULL);
 388         if (err) {
 389                 pr_debug("Failed to parse event %s\n", sched_switch);
 390                 goto out_err;
 391         }
 392
 393         switch_evsel = perf_evlist__last(evlist);
 394
 395         perf_evsel__set_sample_bit(switch_evsel, CPU);
 396         perf_evsel__set_sample_bit(switch_evsel, TIME);
 397
 398         switch_evsel->system_wide = true;
 399         switch_evsel->no_aux_samples = true;
 400         switch_evsel->immediate = true;
 401
 402         /* Test moving an event to the front */
 403         if (cycles_evsel == perf_evlist__first(evlist)) {
 404                 pr_debug("cycles event already at front");
 405                 goto out_err;
 406         }
 407         perf_evlist__to_front(evlist, cycles_evsel);
 408         if (cycles_evsel != perf_evlist__first(evlist)) {
 409                 pr_debug("Failed to move cycles event to front");
 410                 goto out_err;
 411         }
 412
 413         perf_evsel__set_sample_bit(cycles_evsel, CPU);
 414         perf_evsel__set_sample_bit(cycles_evsel, TIME);
 415
 416         /* Fourth event */
 417         err = parse_events(evlist, "dummy:u", NULL);
 418         if (err) {
 419                 pr_debug("Failed to parse event dummy:u\n");
 420                 goto out_err;
 421         }
 422
 423         tracking_evsel = perf_evlist__last(evlist);
 424
 425         perf_evlist__set_tracking_event(evlist, tracking_evsel);
 426
 427         tracking_evsel->core.attr.freq = 0;
 428         tracking_evsel->core.attr.sample_period = 1;
 429
 430         perf_evsel__set_sample_bit(tracking_evsel, TIME);
 431
 432         /* Config events */
 433         perf_evlist__config(evlist, &opts, NULL);
 434
 435         /* Check moved event is still at the front */
 436         if (cycles_evsel != perf_evlist__first(evlist)) {
 437                 pr_debug("Front event no longer at front");
 438                 goto out_err;
 439         }
 440
 441         /* Check tracking event is tracking */
 442         if (!tracking_evsel->core.attr.mmap || !tracking_evsel->core.attr.comm) {
 443                 pr_debug("Tracking event not tracking\n");
 444                 goto out_err;
 445         }
 446
 447         /* Check non-tracking events are not tracking */
 448         evlist__for_each_entry(evlist, evsel) {
 449                 if (evsel != tracking_evsel) {
 450                         if (evsel->core.attr.mmap || evsel->core.attr.comm) {
 451                                 pr_debug("Non-tracking event is tracking\n");
 452                                 goto out_err;
 453                         }
 454                 }
 455         }
 456
 457         if (evlist__open(evlist) < 0) {
 458                 pr_debug("Not supported\n");
 459                 err = 0;
 460                 goto out;
 461         }
 462
 463         err = perf_evlist__mmap(evlist, UINT_MAX);
 464         if (err) {
 465                 pr_debug("perf_evlist__mmap failed!\n");
 466                 goto out_err;
 467         }
 468
 469         evlist__enable(evlist);
 470
 471         err = evsel__disable(cpu_clocks_evsel);
 472         if (err) {
 473                 pr_debug("perf_evlist__disable_event failed!\n");
 474                 goto out_err;
 475         }
 476
 477         err = spin_sleep();
 478         if (err) {
 479                 pr_debug("spin_sleep failed!\n");
 480                 goto out_err;
 481         }
 482
 483         comm = "Test COMM 1";
 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 = evsel__disable(cycles_evsel);
 491         if (err) {
 492                 pr_debug("perf_evlist__disable_event failed!\n");
 493                 goto out_err;
 494         }
 495
 496         comm = "Test COMM 2";
 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 = spin_sleep();
 504         if (err) {
 505                 pr_debug("spin_sleep failed!\n");
 506                 goto out_err;
 507         }
 508
 509         comm = "Test COMM 3";
 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 = evsel__enable(cycles_evsel);
 517         if (err) {
 518                 pr_debug("perf_evlist__disable_event failed!\n");
 519                 goto out_err;
 520         }
 521
 522         comm = "Test COMM 4";
 523         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 524         if (err) {
 525                 pr_debug("PR_SET_NAME failed!\n");
 526                 goto out_err;
 527         }
 528
 529         err = spin_sleep();
 530         if (err) {
 531                 pr_debug("spin_sleep failed!\n");
 532                 goto out_err;
 533         }
 534
 535         evlist__disable(evlist);
 536
 537         switch_tracking.switch_evsel = switch_evsel;
 538         switch_tracking.cycles_evsel = cycles_evsel;
 539
 540         err = process_events(evlist, &switch_tracking);
 541
 542         zfree(&switch_tracking.tids);
 543
 544         if (err)
 545                 goto out_err;
 546
 547         /* Check all 4 comm events were seen i.e. that evsel->tracking works */
 548         if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
 549             !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
 550                 pr_debug("Missing comm events\n");
 551                 goto out_err;
 552         }
 553
 554         /* Check cycles event got enabled */
 555         if (!switch_tracking.cycles_before_comm_1) {
 556                 pr_debug("Missing cycles events\n");
 557                 goto out_err;
 558         }
 559
 560         /* Check cycles event got disabled */
 561         if (switch_tracking.cycles_between_comm_2_and_comm_3) {
 562                 pr_debug("cycles events even though event was disabled\n");
 563                 goto out_err;
 564         }
 565
 566         /* Check cycles event got enabled again */
 567         if (!switch_tracking.cycles_after_comm_4) {
 568                 pr_debug("Missing cycles events\n");
 569                 goto out_err;
 570         }
 571 out:
 572         if (evlist) {
 573                 evlist__disable(evlist);
 574                 evlist__delete(evlist);
 575         } else {
 576                 perf_cpu_map__put(cpus);
 577                 perf_thread_map__put(threads);
 578         }
 579
 580         return err;
 581
 582 out_err:
 583         err = -1;
 584         goto out;
 585 }