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 #include "pmu.h"
  22
  23 static int spin_sleep(void)
  24 {
  25         struct timeval start, now, diff, maxtime;
  26         struct timespec ts;
  27         int err, i;
  28
  29         maxtime.tv_sec = 0;
  30         maxtime.tv_usec = 50000;
  31
  32         err = gettimeofday(&start, NULL);
  33         if (err)
  34                 return err;
  35
  36         /* Spin for 50ms */
  37         while (1) {
  38                 for (i = 0; i < 1000; i++)
  39                         barrier();
  40
  41                 err = gettimeofday(&now, NULL);
  42                 if (err)
  43                         return err;
  44
  45                 timersub(&now, &start, &diff);
  46                 if (timercmp(&diff, &maxtime, > /* For checkpatch */))
  47                         break;
  48         }
  49
  50         ts.tv_nsec = 50 * 1000 * 1000;
  51         ts.tv_sec = 0;
  52
  53         /* Sleep for 50ms */
  54         err = nanosleep(&ts, NULL);
  55         if (err == EINTR)
  56                 err = 0;
  57
  58         return err;
  59 }
  60
  61 struct switch_tracking {
  62         struct evsel *switch_evsel;
  63         struct evsel *cycles_evsel;
  64         pid_t *tids;
  65         int nr_tids;
  66         int comm_seen[4];
  67         int cycles_before_comm_1;
  68         int cycles_between_comm_2_and_comm_3;
  69         int cycles_after_comm_4;
  70 };
  71
  72 static int check_comm(struct switch_tracking *switch_tracking,
  73                       union perf_event *event, const char *comm, int nr)
  74 {
  75         if (event->header.type == PERF_RECORD_COMM &&
  76             (pid_t)event->comm.pid == getpid() &&
  77             (pid_t)event->comm.tid == getpid() &&
  78             strcmp(event->comm.comm, comm) == 0) {
  79                 if (switch_tracking->comm_seen[nr]) {
  80                         pr_debug("Duplicate comm event\n");
  81                         return -1;
  82                 }
  83                 switch_tracking->comm_seen[nr] = 1;
  84                 pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
  85                 return 1;
  86         }
  87         return 0;
  88 }
  89
  90 static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
  91 {
  92         int i, nr = cpu + 1;
  93
  94         if (cpu < 0)
  95                 return -1;
  96
  97         if (!switch_tracking->tids) {
  98                 switch_tracking->tids = calloc(nr, sizeof(pid_t));
  99                 if (!switch_tracking->tids)
 100                         return -1;
 101                 for (i = 0; i < nr; i++)
 102                         switch_tracking->tids[i] = -1;
 103                 switch_tracking->nr_tids = nr;
 104                 return 0;
 105         }
 106
 107         if (cpu >= switch_tracking->nr_tids) {
 108                 void *addr;
 109
 110                 addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
 111                 if (!addr)
 112                         return -1;
 113                 switch_tracking->tids = addr;
 114                 for (i = switch_tracking->nr_tids; i < nr; i++)
 115                         switch_tracking->tids[i] = -1;
 116                 switch_tracking->nr_tids = nr;
 117                 return 0;
 118         }
 119
 120         return 0;
 121 }
 122
 123 static int process_sample_event(struct evlist *evlist,
 124                                 union perf_event *event,
 125                                 struct switch_tracking *switch_tracking)
 126 {
 127         struct perf_sample sample;
 128         struct evsel *evsel;
 129         pid_t next_tid, prev_tid;
 130         int cpu, err;
 131
 132         if (evlist__parse_sample(evlist, event, &sample)) {
 133                 pr_debug("evlist__parse_sample failed\n");
 134                 return -1;
 135         }
 136
 137         evsel = evlist__id2evsel(evlist, sample.id);
 138         if (evsel == switch_tracking->switch_evsel) {
 139                 next_tid = evsel__intval(evsel, &sample, "next_pid");
 140                 prev_tid = evsel__intval(evsel, &sample, "prev_pid");
 141                 cpu = sample.cpu;
 142                 pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
 143                           cpu, prev_tid, next_tid);
 144                 err = check_cpu(switch_tracking, cpu);
 145                 if (err)
 146                         return err;
 147                 /*
 148                  * Check for no missing sched_switch events i.e. that the
 149                  * evsel->core.system_wide flag has worked.
 150                  */
 151                 if (switch_tracking->tids[cpu] != -1 &&
 152                     switch_tracking->tids[cpu] != prev_tid) {
 153                         pr_debug("Missing sched_switch events\n");
 154                         return -1;
 155                 }
 156                 switch_tracking->tids[cpu] = next_tid;
 157         }
 158
 159         if (evsel == switch_tracking->cycles_evsel) {
 160                 pr_debug3("cycles event\n");
 161                 if (!switch_tracking->comm_seen[0])
 162                         switch_tracking->cycles_before_comm_1 = 1;
 163                 if (switch_tracking->comm_seen[1] &&
 164                     !switch_tracking->comm_seen[2])
 165                         switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
 166                 if (switch_tracking->comm_seen[3])
 167                         switch_tracking->cycles_after_comm_4 = 1;
 168         }
 169
 170         return 0;
 171 }
 172
 173 static int process_event(struct evlist *evlist, union perf_event *event,
 174                          struct switch_tracking *switch_tracking)
 175 {
 176         if (event->header.type == PERF_RECORD_SAMPLE)
 177                 return process_sample_event(evlist, event, switch_tracking);
 178
 179         if (event->header.type == PERF_RECORD_COMM) {
 180                 int err, done = 0;
 181
 182                 err = check_comm(switch_tracking, event, "Test COMM 1", 0);
 183                 if (err < 0)
 184                         return -1;
 185                 done += err;
 186                 err = check_comm(switch_tracking, event, "Test COMM 2", 1);
 187                 if (err < 0)
 188                         return -1;
 189                 done += err;
 190                 err = check_comm(switch_tracking, event, "Test COMM 3", 2);
 191                 if (err < 0)
 192                         return -1;
 193                 done += err;
 194                 err = check_comm(switch_tracking, event, "Test COMM 4", 3);
 195                 if (err < 0)
 196                         return -1;
 197                 done += err;
 198                 if (done != 1) {
 199                         pr_debug("Unexpected comm event\n");
 200                         return -1;
 201                 }
 202         }
 203
 204         return 0;
 205 }
 206
 207 struct event_node {
 208         struct list_head list;
 209         union perf_event *event;
 210         u64 event_time;
 211 };
 212
 213 static int add_event(struct evlist *evlist, struct list_head *events,
 214                      union perf_event *event)
 215 {
 216         struct perf_sample sample;
 217         struct event_node *node;
 218
 219         node = malloc(sizeof(struct event_node));
 220         if (!node) {
 221                 pr_debug("malloc failed\n");
 222                 return -1;
 223         }
 224         node->event = event;
 225         list_add(&node->list, events);
 226
 227         if (evlist__parse_sample(evlist, event, &sample)) {
 228                 pr_debug("evlist__parse_sample failed\n");
 229                 return -1;
 230         }
 231
 232         if (!sample.time) {
 233                 pr_debug("event with no time\n");
 234                 return -1;
 235         }
 236
 237         node->event_time = sample.time;
 238
 239         return 0;
 240 }
 241
 242 static void free_event_nodes(struct list_head *events)
 243 {
 244         struct event_node *node;
 245
 246         while (!list_empty(events)) {
 247                 node = list_entry(events->next, struct event_node, list);
 248                 list_del_init(&node->list);
 249                 free(node);
 250         }
 251 }
 252
 253 static int compar(const void *a, const void *b)
 254 {
 255         const struct event_node *nodea = a;
 256         const struct event_node *nodeb = b;
 257         s64 cmp = nodea->event_time - nodeb->event_time;
 258
 259         return cmp;
 260 }
 261
 262 static int process_events(struct evlist *evlist,
 263                           struct switch_tracking *switch_tracking)
 264 {
 265         union perf_event *event;
 266         unsigned pos, cnt = 0;
 267         LIST_HEAD(events);
 268         struct event_node *events_array, *node;
 269         struct mmap *md;
 270         int i, ret;
 271
 272         for (i = 0; i < evlist->core.nr_mmaps; i++) {
 273                 md = &evlist->mmap[i];
 274                 if (perf_mmap__read_init(&md->core) < 0)
 275                         continue;
 276
 277                 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
 278                         cnt += 1;
 279                         ret = add_event(evlist, &events, event);
 280                          perf_mmap__consume(&md->core);
 281                         if (ret < 0)
 282                                 goto out_free_nodes;
 283                 }
 284                 perf_mmap__read_done(&md->core);
 285         }
 286
 287         events_array = calloc(cnt, sizeof(struct event_node));
 288         if (!events_array) {
 289                 pr_debug("calloc failed\n");
 290                 ret = -1;
 291                 goto out_free_nodes;
 292         }
 293
 294         pos = 0;
 295         list_for_each_entry(node, &events, list)
 296                 events_array[pos++] = *node;
 297
 298         qsort(events_array, cnt, sizeof(struct event_node), compar);
 299
 300         for (pos = 0; pos < cnt; pos++) {
 301                 ret = process_event(evlist, events_array[pos].event,
 302                                     switch_tracking);
 303                 if (ret < 0)
 304                         goto out_free;
 305         }
 306
 307         ret = 0;
 308 out_free:
 309         pr_debug("%u events recorded\n", cnt);
 310         free(events_array);
 311 out_free_nodes:
 312         free_event_nodes(&events);
 313         return ret;
 314 }
 315
 316 /**
 317  * test__switch_tracking - test using sched_switch and tracking events.
 318  *
 319  * This function implements a test that checks that sched_switch events and
 320  * tracking events can be recorded for a workload (current process) using the
 321  * evsel->core.system_wide and evsel->tracking flags (respectively) with other events
 322  * sometimes enabled or disabled.
 323  */
 324 static int test__switch_tracking(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
 325 {
 326         const char *sched_switch = "sched:sched_switch";
 327         const char *cycles = "cycles:u";
 328         struct switch_tracking switch_tracking = { .tids = NULL, };
 329         struct record_opts opts = {
 330                 .mmap_pages          = UINT_MAX,
 331                 .user_freq           = UINT_MAX,
 332                 .user_interval       = ULLONG_MAX,
 333                 .freq                = 4000,
 334                 .target              = {
 335                         .uses_mmap   = true,
 336                 },
 337         };
 338         struct perf_thread_map *threads = NULL;
 339         struct perf_cpu_map *cpus = NULL;
 340         struct evlist *evlist = NULL;
 341         struct evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
 342         struct evsel *switch_evsel, *tracking_evsel;
 343         const char *comm;
 344         int err = -1;
 345
 346         threads = thread_map__new(-1, getpid(), UINT_MAX);
 347         if (!threads) {
 348                 pr_debug("thread_map__new failed!\n");
 349                 goto out_err;
 350         }
 351
 352         cpus = perf_cpu_map__new(NULL);
 353         if (!cpus) {
 354                 pr_debug("perf_cpu_map__new failed!\n");
 355                 goto out_err;
 356         }
 357
 358         evlist = evlist__new();
 359         if (!evlist) {
 360                 pr_debug("evlist__new failed!\n");
 361                 goto out_err;
 362         }
 363
 364         perf_evlist__set_maps(&evlist->core, cpus, threads);
 365
 366         /* First event */
 367         err = parse_event(evlist, "cpu-clock:u");
 368         if (err) {
 369                 pr_debug("Failed to parse event dummy:u\n");
 370                 goto out_err;
 371         }
 372
 373         cpu_clocks_evsel = evlist__last(evlist);
 374
 375         /* Second event */
 376         if (perf_pmu__has_hybrid()) {
 377                 cycles = "cpu_core/cycles/u";
 378                 err = parse_event(evlist, cycles);
 379                 if (err) {
 380                         cycles = "cpu_atom/cycles/u";
 381                         pr_debug("Trying %s\n", cycles);
 382                         err = parse_event(evlist, cycles);
 383                 }
 384         } else {
 385                 err = parse_event(evlist, cycles);
 386         }
 387         if (err) {
 388                 pr_debug("Failed to parse event %s\n", cycles);
 389                 goto out_err;
 390         }
 391
 392         cycles_evsel = evlist__last(evlist);
 393
 394         /* Third event */
 395         if (!evlist__can_select_event(evlist, sched_switch)) {
 396                 pr_debug("No sched_switch\n");
 397                 err = 0;
 398                 goto out;
 399         }
 400
 401         err = parse_event(evlist, sched_switch);
 402         if (err) {
 403                 pr_debug("Failed to parse event %s\n", sched_switch);
 404                 goto out_err;
 405         }
 406
 407         switch_evsel = evlist__last(evlist);
 408
 409         evsel__set_sample_bit(switch_evsel, CPU);
 410         evsel__set_sample_bit(switch_evsel, TIME);
 411
 412         switch_evsel->core.system_wide = true;
 413         switch_evsel->no_aux_samples = true;
 414         switch_evsel->immediate = true;
 415
 416         /* Test moving an event to the front */
 417         if (cycles_evsel == evlist__first(evlist)) {
 418                 pr_debug("cycles event already at front");
 419                 goto out_err;
 420         }
 421         evlist__to_front(evlist, cycles_evsel);
 422         if (cycles_evsel != evlist__first(evlist)) {
 423                 pr_debug("Failed to move cycles event to front");
 424                 goto out_err;
 425         }
 426
 427         evsel__set_sample_bit(cycles_evsel, CPU);
 428         evsel__set_sample_bit(cycles_evsel, TIME);
 429
 430         /* Fourth event */
 431         err = parse_event(evlist, "dummy:u");
 432         if (err) {
 433                 pr_debug("Failed to parse event dummy:u\n");
 434                 goto out_err;
 435         }
 436
 437         tracking_evsel = evlist__last(evlist);
 438
 439         evlist__set_tracking_event(evlist, tracking_evsel);
 440
 441         tracking_evsel->core.attr.freq = 0;
 442         tracking_evsel->core.attr.sample_period = 1;
 443
 444         evsel__set_sample_bit(tracking_evsel, TIME);
 445
 446         /* Config events */
 447         evlist__config(evlist, &opts, NULL);
 448
 449         /* Check moved event is still at the front */
 450         if (cycles_evsel != evlist__first(evlist)) {
 451                 pr_debug("Front event no longer at front");
 452                 goto out_err;
 453         }
 454
 455         /* Check tracking event is tracking */
 456         if (!tracking_evsel->core.attr.mmap || !tracking_evsel->core.attr.comm) {
 457                 pr_debug("Tracking event not tracking\n");
 458                 goto out_err;
 459         }
 460
 461         /* Check non-tracking events are not tracking */
 462         evlist__for_each_entry(evlist, evsel) {
 463                 if (evsel != tracking_evsel) {
 464                         if (evsel->core.attr.mmap || evsel->core.attr.comm) {
 465                                 pr_debug("Non-tracking event is tracking\n");
 466                                 goto out_err;
 467                         }
 468                 }
 469         }
 470
 471         if (evlist__open(evlist) < 0) {
 472                 pr_debug("Not supported\n");
 473                 err = 0;
 474                 goto out;
 475         }
 476
 477         err = evlist__mmap(evlist, UINT_MAX);
 478         if (err) {
 479                 pr_debug("evlist__mmap failed!\n");
 480                 goto out_err;
 481         }
 482
 483         evlist__enable(evlist);
 484
 485         err = evsel__disable(cpu_clocks_evsel);
 486         if (err) {
 487                 pr_debug("perf_evlist__disable_event 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 1";
 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 = evsel__disable(cycles_evsel);
 505         if (err) {
 506                 pr_debug("perf_evlist__disable_event failed!\n");
 507                 goto out_err;
 508         }
 509
 510         comm = "Test COMM 2";
 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         comm = "Test COMM 3";
 524         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 525         if (err) {
 526                 pr_debug("PR_SET_NAME failed!\n");
 527                 goto out_err;
 528         }
 529
 530         err = evsel__enable(cycles_evsel);
 531         if (err) {
 532                 pr_debug("perf_evlist__disable_event failed!\n");
 533                 goto out_err;
 534         }
 535
 536         comm = "Test COMM 4";
 537         err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 538         if (err) {
 539                 pr_debug("PR_SET_NAME failed!\n");
 540                 goto out_err;
 541         }
 542
 543         err = spin_sleep();
 544         if (err) {
 545                 pr_debug("spin_sleep failed!\n");
 546                 goto out_err;
 547         }
 548
 549         evlist__disable(evlist);
 550
 551         switch_tracking.switch_evsel = switch_evsel;
 552         switch_tracking.cycles_evsel = cycles_evsel;
 553
 554         err = process_events(evlist, &switch_tracking);
 555
 556         zfree(&switch_tracking.tids);
 557
 558         if (err)
 559                 goto out_err;
 560
 561         /* Check all 4 comm events were seen i.e. that evsel->tracking works */
 562         if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
 563             !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
 564                 pr_debug("Missing comm events\n");
 565                 goto out_err;
 566         }
 567
 568         /* Check cycles event got enabled */
 569         if (!switch_tracking.cycles_before_comm_1) {
 570                 pr_debug("Missing cycles events\n");
 571                 goto out_err;
 572         }
 573
 574         /* Check cycles event got disabled */
 575         if (switch_tracking.cycles_between_comm_2_and_comm_3) {
 576                 pr_debug("cycles events even though event was disabled\n");
 577                 goto out_err;
 578         }
 579
 580         /* Check cycles event got enabled again */
 581         if (!switch_tracking.cycles_after_comm_4) {
 582                 pr_debug("Missing cycles events\n");
 583                 goto out_err;
 584         }
 585 out:
 586         if (evlist) {
 587                 evlist__disable(evlist);
 588                 evlist__delete(evlist);
 589         }
 590         perf_cpu_map__put(cpus);
 591         perf_thread_map__put(threads);
 592
 593         return err;
 594
 595 out_err:
 596         err = -1;
 597         goto out;
 598 }
 599
 600 DEFINE_SUITE("Track with sched_switch", switch_tracking);