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 "cpumap.h"
  18 #include "record.h"
  19 #include "tests.h"
  20
  21 static int spin_sleep(void)
  22 {
  23         struct timeval start, now, diff, maxtime;
  24         struct timespec ts;
  25         int err, i;
  26
  27         maxtime.tv_sec = 0;
  28         maxtime.tv_usec = 50000;
  29
  30         err = gettimeofday(&start, NULL);
  31         if (err)
  32                 return err;
  33
  34         /* Spin for 50ms */
  35         while (1) {
  36                 for (i = 0; i < 1000; i++)
  37                         barrier();
  38
  39                 err = gettimeofday(&now, NULL);
  40                 if (err)
  41                         return err;
  42
  43                 timersub(&now, &start, &diff);
  44                 if (timercmp(&diff, &maxtime, > /* For checkpatch */))
  45                         break;
  46         }
  47
  48         ts.tv_nsec = 50 * 1000 * 1000;
  49         ts.tv_sec = 0;
  50
  51         /* Sleep for 50ms */
  52         err = nanosleep(&ts, NULL);
  53         if (err == EINTR)
  54                 err = 0;
  55
  56         return err;
  57 }
  58
  59 struct switch_tracking {
  60         struct evsel *switch_evsel;
  61         struct evsel *cycles_evsel;
  62         pid_t *tids;
  63         int nr_tids;
  64         int comm_seen[4];
  65         int cycles_before_comm_1;
  66         int cycles_between_comm_2_and_comm_3;
  67         int cycles_after_comm_4;
  68 };
  69
  70 static int check_comm(struct switch_tracking *switch_tracking,
  71                       union perf_event *event, const char *comm, int nr)
  72 {
  73         if (event->header.type == PERF_RECORD_COMM &&
  74             (pid_t)event->comm.pid == getpid() &&
  75             (pid_t)event->comm.tid == getpid() &&
  76             strcmp(event->comm.comm, comm) == 0) {
  77                 if (switch_tracking->comm_seen[nr]) {
  78                         pr_debug("Duplicate comm event\n");
  79                         return -1;
  80                 }
  81                 switch_tracking->comm_seen[nr] = 1;
  82                 pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
  83                 return 1;
  84         }
  85         return 0;
  86 }
  87
  88 static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
  89 {
  90         int i, nr = cpu + 1;
  91
  92         if (cpu < 0)
  93                 return -1;
  94
  95         if (!switch_tracking->tids) {
  96                 switch_tracking->tids = calloc(nr, sizeof(pid_t));
  97                 if (!switch_tracking->tids)
  98                         return -1;
  99                 for (i = 0; i < nr; i++)
 100                         switch_tracking->tids[i] = -1;
 101                 switch_tracking->nr_tids = nr;
 102                 return 0;
 103         }
 104
 105         if (cpu >= switch_tracking->nr_tids) {
 106                 void *addr;
 107
 108                 addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
 109                 if (!addr)
 110                         return -1;
 111                 switch_tracking->tids = addr;
 112                 for (i = switch_tracking->nr_tids; i < nr; i++)
 113                         switch_tracking->tids[i] = -1;
 114                 switch_tracking->nr_tids = nr;
 115                 return 0;
 116         }
 117
 118         return 0;
 119 }
 120
 121 static int process_sample_event(struct evlist *evlist,
 122                                 union perf_event *event,
 123                                 struct switch_tracking *switch_tracking)
 124 {
 125         struct perf_sample sample;
 126         struct evsel *evsel;
 127         pid_t next_tid, prev_tid;
 128         int cpu, err;
 129
 130         if (perf_evlist__parse_sample(evlist, event, &sample)) {
 131                 pr_debug("perf_evlist__parse_sample failed\n");
 132                 return -1;
 133         }
 134
 135         evsel = perf_evlist__id2evsel(evlist, sample.id);
 136         if (evsel == switch_tracking->switch_evsel) {
 137                 next_tid = perf_evsel__intval(evsel, &sample, "next_pid");
 138                 prev_tid = perf_evsel__intval(evsel, &sample, "prev_pid");
 139                 cpu = sample.cpu;
 140                 pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
 141                           cpu, prev_tid, next_tid);
 142                 err = check_cpu(switch_tracking, cpu);
 143                 if (err)
 144                         return err;
 145                 /*
 146                  * Check for no missing sched_switch events i.e. that the
 147                  * evsel->system_wide flag has worked.
 148                  */
 149                 if (switch_tracking->tids[cpu] != -1 &&
 150                     switch_tracking->tids[cpu] != prev_tid) {
 151                         pr_debug("Missing sched_switch events\n");
 152                         return -1;
 153                 }
 154                 switch_tracking->tids[cpu] = next_tid;
 155         }
 156
 157         if (evsel == switch_tracking->cycles_evsel) {
 158                 pr_debug3("cycles event\n");
 159                 if (!switch_tracking->comm_seen[0])
 160                         switch_tracking->cycles_before_comm_1 = 1;
 161                 if (switch_tracking->comm_seen[1] &&
 162                     !switch_tracking->comm_seen[2])
 163                         switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
 164                 if (switch_tracking->comm_seen[3])
 165                         switch_tracking->cycles_after_comm_4 = 1;
 166         }
 167
 168         return 0;
 169 }
 170
 171 static int process_event(struct evlist *evlist, union perf_event *event,
 172                          struct switch_tracking *switch_tracking)
 173 {
 174         if (event->header.type == PERF_RECORD_SAMPLE)
 175                 return process_sample_event(evlist, event, switch_tracking);
 176
 177         if (event->header.type == PERF_RECORD_COMM) {
 178                 int err, done = 0;
 179
 180                 err = check_comm(switch_tracking, event, "Test COMM 1", 0);
 181                 if (err < 0)
 182                         return -1;
 183                 done += err;
 184                 err = check_comm(switch_tracking, event, "Test COMM 2", 1);
 185                 if (err < 0)
 186                         return -1;
 187                 done += err;
 188                 err = check_comm(switch_tracking, event, "Test COMM 3", 2);
 189                 if (err < 0)
 190                         return -1;
 191                 done += err;
 192                 err = check_comm(switch_tracking, event, "Test COMM 4", 3);
 193                 if (err < 0)
 194                         return -1;
 195                 done += err;
 196                 if (done != 1) {
 197                         pr_debug("Unexpected comm event\n");
 198                         return -1;
 199                 }
 200         }
 201
 202         return 0;
 203 }
 204
 205 struct event_node {
 206         struct list_head list;
 207         union perf_event *event;
 208         u64 event_time;
 209 };
 210
 211 static int add_event(struct evlist *evlist, struct list_head *events,
 212                      union perf_event *event)
 213 {
 214         struct perf_sample sample;
 215         struct event_node *node;
 216
 217         node = malloc(sizeof(struct event_node));
 218         if (!node) {
 219                 pr_debug("malloc failed\n");
 220                 return -1;
 221         }
 222         node->event = event;
 223         list_add(&node->list, events);
 224
 225         if (perf_evlist__parse_sample(evlist, event, &sample)) {
 226                 pr_debug("perf_evlist__parse_sample failed\n");
 227                 return -1;
 228         }
 229
 230         if (!sample.time) {
 231                 pr_debug("event with no time\n");
 232                 return -1;
 233         }
 234
 235         node->event_time = sample.time;
 236
 237         return 0;
 238 }
 239
 240 static void free_event_nodes(struct list_head *events)
 241 {
 242         struct event_node *node;
 243
 244         while (!list_empty(events)) {
 245                 node = list_entry(events->next, struct event_node, list);
 246                 list_del_init(&node->list);
 247                 free(node);
 248         }
 249 }
 250
 251 static int compar(const void *a, const void *b)
 252 {
 253         const struct event_node *nodea = a;
 254         const struct event_node *nodeb = b;
 255         s64 cmp = nodea->event_time - nodeb->event_time;
 256
 257         return cmp;
 258 }
 259
 260 static int process_events(struct evlist *evlist,
 261                           struct switch_tracking *switch_tracking)
 262 {
 263         union perf_event *event;
 264         unsigned pos, cnt = 0;
 265         LIST_HEAD(events);
 266         struct event_node *events_array, *node;
 267         struct perf_mmap *md;
 268         int i, ret;
 269
 270         for (i = 0; i < evlist->nr_mmaps; i++) {
 271                 md = &evlist->mmap[i];
 272                 if (perf_mmap__read_init(md) < 0)
 273                         continue;
 274
 275                 while ((event = perf_mmap__read_event(md)) != NULL) {
 276                         cnt += 1;
 277                         ret = add_event(evlist, &events, event);
 278                          perf_mmap__consume(md);
 279                         if (ret < 0)
 280                                 goto out_free_nodes;
 281                 }
 282                 perf_mmap__read_done(md);
 283         }
 284
 285         events_array = calloc(cnt, sizeof(struct event_node));
 286         if (!events_array) {
 287                 pr_debug("calloc failed\n");
 288                 ret = -1;
 289                 goto out_free_nodes;
 290         }
 291
 292         pos = 0;
 293         list_for_each_entry(node, &events, list)
 294                 events_array[pos++] = *node;
 295
 296         qsort(events_array, cnt, sizeof(struct event_node), compar);
 297
 298         for (pos = 0; pos < cnt; pos++) {
 299                 ret = process_event(evlist, events_array[pos].event,
 300                                     switch_tracking);
 301                 if (ret < 0)
 302                         goto out_free;
 303         }
 304
 305         ret = 0;
 306 out_free:
 307         pr_debug("%u events recorded\n", cnt);
 308         free(events_array);
 309 out_free_nodes:
 310         free_event_nodes(&events);
 311         return ret;
 312 }
 313
 314 /**
 315  * test__switch_tracking - test using sched_switch and tracking events.
 316  *
 317  * This function implements a test that checks that sched_switch events and
 318  * tracking events can be recorded for a workload (current process) using the
 319  * evsel->system_wide and evsel->tracking flags (respectively) with other events
 320  * sometimes enabled or disabled.
 321  */
 322 int test__switch_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
 323 {
 324         const char *sched_switch = "sched:sched_switch";
 325         struct switch_tracking switch_tracking = { .tids = NULL, };
 326         struct record_opts opts = {
 327                 .mmap_pages          = UINT_MAX,
 328                 .user_freq           = UINT_MAX,
 329                 .user_interval       = ULLONG_MAX,
 330                 .freq                = 4000,
 331                 .target              = {
 332                         .uses_mmap   = true,
 333                 },
 334         };
 335         struct perf_thread_map *threads = NULL;
 336         struct perf_cpu_map *cpus = NULL;
 337         struct evlist *evlist = NULL;
 338         struct evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
 339         struct evsel *switch_evsel, *tracking_evsel;
 340         const char *comm;
 341         int err = -1;
 342
 343         threads = thread_map__new(-1, getpid(), UINT_MAX);
 344         if (!threads) {
 345                 pr_debug("thread_map__new failed!\n");
 346                 goto out_err;
 347         }
 348
 349         cpus = perf_cpu_map__new(NULL);
 350         if (!cpus) {
 351                 pr_debug("perf_cpu_map__new failed!\n");
 352                 goto out_err;
 353         }
 354
 355         evlist = evlist__new();
 356         if (!evlist) {
 357                 pr_debug("evlist__new failed!\n");
 358                 goto out_err;
 359         }
 360
 361         perf_evlist__set_maps(&evlist->core, cpus, threads);
 362
 363         /* First event */
 364         err = parse_events(evlist, "cpu-clock:u", NULL);
 365         if (err) {
 366                 pr_debug("Failed to parse event dummy:u\n");
 367                 goto out_err;
 368         }
 369
 370         cpu_clocks_evsel = perf_evlist__last(evlist);
 371
 372         /* Second event */
 373         err = parse_events(evlist, "cycles:u", NULL);
 374         if (err) {
 375                 pr_debug("Failed to parse event cycles:u\n");
 376                 goto out_err;
 377         }
 378
 379         cycles_evsel = perf_evlist__last(evlist);
 380
 381         /* Third event */
 382         if (!perf_evlist__can_select_event(evlist, sched_switch)) {
 383                 pr_debug("No sched_switch\n");
 384                 err = 0;
 385                 goto out;
 386         }
 387
 388         err = parse_events(evlist, sched_switch, NULL);
 389         if (err) {
 390                 pr_debug("Failed to parse event %s\n", sched_switch);
 391                 goto out_err;
 392         }
 393
 394         switch_evsel = perf_evlist__last(evlist);
 395
 396         perf_evsel__set_sample_bit(switch_evsel, CPU);
 397         perf_evsel__set_sample_bit(switch_evsel, TIME);
 398
 399         switch_evsel->system_wide = true;
 400         switch_evsel->no_aux_samples = true;
 401         switch_evsel->immediate = true;
 402
 403         /* Test moving an event to the front */
 404         if (cycles_evsel == perf_evlist__first(evlist)) {
 405                 pr_debug("cycles event already at front");
 406                 goto out_err;
 407         }
 408         perf_evlist__to_front(evlist, cycles_evsel);
 409         if (cycles_evsel != perf_evlist__first(evlist)) {
 410                 pr_debug("Failed to move cycles event to front");
 411                 goto out_err;
 412         }
 413
 414         perf_evsel__set_sample_bit(cycles_evsel, CPU);
 415         perf_evsel__set_sample_bit(cycles_evsel, TIME);
 416
 417         /* Fourth event */
 418         err = parse_events(evlist, "dummy:u", NULL);
 419         if (err) {
 420                 pr_debug("Failed to parse event dummy:u\n");
 421                 goto out_err;
 422         }
 423
 424         tracking_evsel = perf_evlist__last(evlist);
 425
 426         perf_evlist__set_tracking_event(evlist, tracking_evsel);
 427
 428         tracking_evsel->core.attr.freq = 0;
 429         tracking_evsel->core.attr.sample_period = 1;
 430
 431         perf_evsel__set_sample_bit(tracking_evsel, TIME);
 432
 433         /* Config events */
 434         perf_evlist__config(evlist, &opts, NULL);
 435
 436         /* Check moved event is still at the front */
 437         if (cycles_evsel != perf_evlist__first(evlist)) {
 438                 pr_debug("Front event no longer at front");
 439                 goto out_err;
 440         }
 441
 442         /* Check tracking event is tracking */
 443         if (!tracking_evsel->core.attr.mmap || !tracking_evsel->core.attr.comm) {
 444                 pr_debug("Tracking event not tracking\n");
 445                 goto out_err;
 446         }
 447
 448         /* Check non-tracking events are not tracking */
 449         evlist__for_each_entry(evlist, evsel) {
 450                 if (evsel != tracking_evsel) {
 451                         if (evsel->core.attr.mmap || evsel->core.attr.comm) {
 452                                 pr_debug("Non-tracking event is tracking\n");
 453                                 goto out_err;
 454                         }
 455                 }
 456         }
 457
 458         if (evlist__open(evlist) < 0) {
 459                 pr_debug("Not supported\n");
 460                 err = 0;
 461                 goto out;
 462         }
 463
 464         err = perf_evlist__mmap(evlist, UINT_MAX);
 465         if (err) {
 466                 pr_debug("perf_evlist__mmap failed!\n");
 467                 goto out_err;
 468         }
 469
 470         evlist__enable(evlist);
 471
 472         err = evsel__disable(cpu_clocks_evsel);
 473         if (err) {
 474                 pr_debug("perf_evlist__disable_event failed!\n");
 475                 goto out_err;
 476         }
 477
 478         err = spin_sleep();
 479         if (err) {
 480                 pr_debug("spin_sleep failed!\n");
 481                 goto out_err;
 482         }
 483
 484         comm = "Test COMM 1";
 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 = evsel__disable(cycles_evsel);
 492         if (err) {
 493                 pr_debug("perf_evlist__disable_event failed!\n");
 494                 goto out_err;
 495         }
 496
 497         comm = "Test COMM 2";
 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 = spin_sleep();
 505         if (err) {
 506                 pr_debug("spin_sleep failed!\n");
 507                 goto out_err;
 508         }
 509
 510         comm = "Test COMM 3";
 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 = evsel__enable(cycles_evsel);
 518         if (err) {
 519                 pr_debug("perf_evlist__disable_event failed!\n");
 520                 goto out_err;
 521         }
 522
 523         comm = "Test COMM 4";
 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 = spin_sleep();
 531         if (err) {
 532                 pr_debug("spin_sleep failed!\n");
 533                 goto out_err;
 534         }
 535
 536         evlist__disable(evlist);
 537
 538         switch_tracking.switch_evsel = switch_evsel;
 539         switch_tracking.cycles_evsel = cycles_evsel;
 540
 541         err = process_events(evlist, &switch_tracking);
 542
 543         zfree(&switch_tracking.tids);
 544
 545         if (err)
 546                 goto out_err;
 547
 548         /* Check all 4 comm events were seen i.e. that evsel->tracking works */
 549         if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
 550             !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
 551                 pr_debug("Missing comm events\n");
 552                 goto out_err;
 553         }
 554
 555         /* Check cycles event got enabled */
 556         if (!switch_tracking.cycles_before_comm_1) {
 557                 pr_debug("Missing cycles events\n");
 558                 goto out_err;
 559         }
 560
 561         /* Check cycles event got disabled */
 562         if (switch_tracking.cycles_between_comm_2_and_comm_3) {
 563                 pr_debug("cycles events even though event was disabled\n");
 564                 goto out_err;
 565         }
 566
 567         /* Check cycles event got enabled again */
 568         if (!switch_tracking.cycles_after_comm_4) {
 569                 pr_debug("Missing cycles events\n");
 570                 goto out_err;
 571         }
 572 out:
 573         if (evlist) {
 574                 evlist__disable(evlist);
 575                 evlist__delete(evlist);
 576         } else {
 577                 perf_cpu_map__put(cpus);
 578                 perf_thread_map__put(threads);
 579         }
 580
 581         return err;
 582
 583 out_err:
 584         err = -1;
 585         goto out;
 586 }