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 <linux/err.h>
  10 #include <perf/cpumap.h>
  11 #include <perf/evlist.h>
  12 #include <perf/mmap.h>
  13
  14 #include "debug.h"
  15 #include "parse-events.h"
  16 #include "evlist.h"
  17 #include "evsel.h"
  18 #include "thread_map.h"
  19 #include "record.h"
  20 #include "tests.h"
  21 #include "util/mmap.h"
  22 #include "util/sample.h"
  23 #include "pmus.h"
  24
  25 static int spin_sleep(void)
  26 {
  27         struct timeval start, now, diff, maxtime;
  28         struct timespec ts;
  29         int err, i;
  30
  31         maxtime.tv_sec = 0;
  32         maxtime.tv_usec = 50000;
  33
  34         err = gettimeofday(&start, NULL);
  35         if (err)
  36                 return err;
  37
  38         /* Spin for 50ms */
  39         while (1) {
  40                 for (i = 0; i < 1000; i++)
  41                         barrier();
  42
  43                 err = gettimeofday(&now, NULL);
  44                 if (err)
  45                         return err;
  46
  47                 timersub(&now, &start, &diff);
  48                 if (timercmp(&diff, &maxtime, > /* For checkpatch */))
  49                         break;
  50         }
  51
  52         ts.tv_nsec = 50 * 1000 * 1000;
  53         ts.tv_sec = 0;
  54
  55         /* Sleep for 50ms */
  56         err = nanosleep(&ts, NULL);
  57         if (err == EINTR)
  58                 err = 0;
  59
  60         return err;
  61 }
  62
  63 struct switch_tracking {
  64         struct evsel *switch_evsel;
  65         struct evsel *cycles_evsel;
  66         pid_t *tids;
  67         int nr_tids;
  68         int comm_seen[4];
  69         int cycles_before_comm_1;
  70         int cycles_between_comm_2_and_comm_3;
  71         int cycles_after_comm_4;
  72 };
  73
  74 static int check_comm(struct switch_tracking *switch_tracking,
  75                       union perf_event *event, const char *comm, int nr)
  76 {
  77         if (event->header.type == PERF_RECORD_COMM &&
  78             (pid_t)event->comm.pid == getpid() &&
  79             (pid_t)event->comm.tid == getpid() &&
  80             strcmp(event->comm.comm, comm) == 0) {
  81                 if (switch_tracking->comm_seen[nr]) {
  82                         pr_debug("Duplicate comm event\n");
  83                         return -1;
  84                 }
  85                 switch_tracking->comm_seen[nr] = 1;
  86                 pr_debug3("comm event: %s nr: %d\n", event->comm.comm, nr);
  87                 return 1;
  88         }
  89         return 0;
  90 }
  91
  92 static int check_cpu(struct switch_tracking *switch_tracking, int cpu)
  93 {
  94         int i, nr = cpu + 1;
  95
  96         if (cpu < 0)
  97                 return -1;
  98
  99         if (!switch_tracking->tids) {
 100                 switch_tracking->tids = calloc(nr, sizeof(pid_t));
 101                 if (!switch_tracking->tids)
 102                         return -1;
 103                 for (i = 0; i < nr; i++)
 104                         switch_tracking->tids[i] = -1;
 105                 switch_tracking->nr_tids = nr;
 106                 return 0;
 107         }
 108
 109         if (cpu >= switch_tracking->nr_tids) {
 110                 void *addr;
 111
 112                 addr = realloc(switch_tracking->tids, nr * sizeof(pid_t));
 113                 if (!addr)
 114                         return -1;
 115                 switch_tracking->tids = addr;
 116                 for (i = switch_tracking->nr_tids; i < nr; i++)
 117                         switch_tracking->tids[i] = -1;
 118                 switch_tracking->nr_tids = nr;
 119                 return 0;
 120         }
 121
 122         return 0;
 123 }
 124
 125 static int process_sample_event(struct evlist *evlist,
 126                                 union perf_event *event,
 127                                 struct switch_tracking *switch_tracking)
 128 {
 129         struct perf_sample sample;
 130         struct evsel *evsel;
 131         pid_t next_tid, prev_tid;
 132         int cpu, err;
 133
 134         if (evlist__parse_sample(evlist, event, &sample)) {
 135                 pr_debug("evlist__parse_sample failed\n");
 136                 return -1;
 137         }
 138
 139         evsel = evlist__id2evsel(evlist, sample.id);
 140         if (evsel == switch_tracking->switch_evsel) {
 141                 next_tid = evsel__intval(evsel, &sample, "next_pid");
 142                 prev_tid = evsel__intval(evsel, &sample, "prev_pid");
 143                 cpu = sample.cpu;
 144                 pr_debug3("sched_switch: cpu: %d prev_tid %d next_tid %d\n",
 145                           cpu, prev_tid, next_tid);
 146                 err = check_cpu(switch_tracking, cpu);
 147                 if (err)
 148                         return err;
 149                 /*
 150                  * Check for no missing sched_switch events i.e. that the
 151                  * evsel->core.system_wide flag has worked.
 152                  */
 153                 if (switch_tracking->tids[cpu] != -1 &&
 154                     switch_tracking->tids[cpu] != prev_tid) {
 155                         pr_debug("Missing sched_switch events\n");
 156                         return -1;
 157                 }
 158                 switch_tracking->tids[cpu] = next_tid;
 159         }
 160
 161         if (evsel == switch_tracking->cycles_evsel) {
 162                 pr_debug3("cycles event\n");
 163                 if (!switch_tracking->comm_seen[0])
 164                         switch_tracking->cycles_before_comm_1 = 1;
 165                 if (switch_tracking->comm_seen[1] &&
 166                     !switch_tracking->comm_seen[2])
 167                         switch_tracking->cycles_between_comm_2_and_comm_3 = 1;
 168                 if (switch_tracking->comm_seen[3])
 169                         switch_tracking->cycles_after_comm_4 = 1;
 170         }
 171
 172         return 0;
 173 }
 174
 175 static int process_event(struct evlist *evlist, union perf_event *event,
 176                          struct switch_tracking *switch_tracking)
 177 {
 178         if (event->header.type == PERF_RECORD_SAMPLE)
 179                 return process_sample_event(evlist, event, switch_tracking);
 180
 181         if (event->header.type == PERF_RECORD_COMM) {
 182                 int err, done = 0;
 183
 184                 err = check_comm(switch_tracking, event, "Test COMM 1", 0);
 185                 if (err < 0)
 186                         return -1;
 187                 done += err;
 188                 err = check_comm(switch_tracking, event, "Test COMM 2", 1);
 189                 if (err < 0)
 190                         return -1;
 191                 done += err;
 192                 err = check_comm(switch_tracking, event, "Test COMM 3", 2);
 193                 if (err < 0)
 194                         return -1;
 195                 done += err;
 196                 err = check_comm(switch_tracking, event, "Test COMM 4", 3);
 197                 if (err < 0)
 198                         return -1;
 199                 done += err;
 200                 if (done != 1) {
 201                         pr_debug("Unexpected comm event\n");
 202                         return -1;
 203                 }
 204         }
 205
 206         return 0;
 207 }
 208
 209 struct event_node {
 210         struct list_head list;
 211         union perf_event *event;
 212         u64 event_time;
 213 };
 214
 215 static int add_event(struct evlist *evlist, struct list_head *events,
 216                      union perf_event *event)
 217 {
 218         struct perf_sample sample;
 219         struct event_node *node;
 220
 221         node = malloc(sizeof(struct event_node));
 222         if (!node) {
 223                 pr_debug("malloc failed\n");
 224                 return -1;
 225         }
 226         node->event = event;
 227         list_add(&node->list, events);
 228
 229         if (evlist__parse_sample(evlist, event, &sample)) {
 230                 pr_debug("evlist__parse_sample failed\n");
 231                 return -1;
 232         }
 233
 234         if (!sample.time) {
 235                 pr_debug("event with no time\n");
 236                 return -1;
 237         }
 238
 239         node->event_time = sample.time;
 240
 241         return 0;
 242 }
 243
 244 static void free_event_nodes(struct list_head *events)
 245 {
 246         struct event_node *node;
 247
 248         while (!list_empty(events)) {
 249                 node = list_entry(events->next, struct event_node, list);
 250                 list_del_init(&node->list);
 251                 free(node);
 252         }
 253 }
 254
 255 static int compar(const void *a, const void *b)
 256 {
 257         const struct event_node *nodea = a;
 258         const struct event_node *nodeb = b;
 259         s64 cmp = nodea->event_time - nodeb->event_time;
 260
 261         return cmp;
 262 }
 263
 264 static int process_events(struct evlist *evlist,
 265                           struct switch_tracking *switch_tracking)
 266 {
 267         union perf_event *event;
 268         unsigned pos, cnt = 0;
 269         LIST_HEAD(events);
 270         struct event_node *events_array, *node;
 271         struct mmap *md;
 272         int i, ret;
 273
 274         for (i = 0; i < evlist->core.nr_mmaps; i++) {
 275                 md = &evlist->mmap[i];
 276                 if (perf_mmap__read_init(&md->core) < 0)
 277                         continue;
 278
 279                 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
 280                         cnt += 1;
 281                         ret = add_event(evlist, &events, event);
 282                          perf_mmap__consume(&md->core);
 283                         if (ret < 0)
 284                                 goto out_free_nodes;
 285                 }
 286                 perf_mmap__read_done(&md->core);
 287         }
 288
 289         events_array = calloc(cnt, sizeof(struct event_node));
 290         if (!events_array) {
 291                 pr_debug("calloc failed\n");
 292                 ret = -1;
 293                 goto out_free_nodes;
 294         }
 295
 296         pos = 0;
 297         list_for_each_entry(node, &events, list)
 298                 events_array[pos++] = *node;
 299
 300         qsort(events_array, cnt, sizeof(struct event_node), compar);
 301
 302         for (pos = 0; pos < cnt; pos++) {
 303                 ret = process_event(evlist, events_array[pos].event,
 304                                     switch_tracking);
 305                 if (ret < 0)
 306                         goto out_free;
 307         }
 308
 309         ret = 0;
 310 out_free:
 311         pr_debug("%u events recorded\n", cnt);
 312         free(events_array);
 313 out_free_nodes:
 314         free_event_nodes(&events);
 315         return ret;
 316 }
 317
 318 /**
 319  * test__switch_tracking - test using sched_switch and tracking events.
 320  *
 321  * This function implements a test that checks that sched_switch events and
 322  * tracking events can be recorded for a workload (current process) using the
 323  * evsel->core.system_wide and evsel->tracking flags (respectively) with other events
 324  * sometimes enabled or disabled.
 325  */
 326 static int test__switch_tracking(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
 327 {
 328         const char *sched_switch = "sched:sched_switch";
 329         const char *cycles = "cycles:u";
 330         struct switch_tracking switch_tracking = { .tids = NULL, };
 331         struct record_opts opts = {
 332                 .mmap_pages          = UINT_MAX,
 333                 .user_freq           = UINT_MAX,
 334                 .user_interval       = ULLONG_MAX,
 335                 .freq                = 4000,
 336                 .target              = {
 337                         .uses_mmap   = true,
 338                 },
 339         };
 340         struct perf_thread_map *threads = NULL;
 341         struct perf_cpu_map *cpus = NULL;
 342         struct evlist *evlist = NULL;
 343         struct evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
 344         struct evsel *switch_evsel, *tracking_evsel;
 345         const char *comm;
 346         int err = -1;
 347
 348         threads = thread_map__new(-1, getpid(), UINT_MAX);
 349         if (!threads) {
 350                 pr_debug("thread_map__new failed!\n");
 351                 goto out_err;
 352         }
 353
 354         cpus = perf_cpu_map__new_online_cpus();
 355         if (!cpus) {
 356                 pr_debug("perf_cpu_map__new failed!\n");
 357                 goto out_err;
 358         }
 359
 360         evlist = evlist__new();
 361         if (!evlist) {
 362                 pr_debug("evlist__new failed!\n");
 363                 goto out_err;
 364         }
 365
 366         perf_evlist__set_maps(&evlist->core, cpus, threads);
 367
 368         /* First event */
 369         err = parse_event(evlist, "cpu-clock:u");
 370         if (err) {
 371                 pr_debug("Failed to parse event dummy:u\n");
 372                 goto out_err;
 373         }
 374
 375         cpu_clocks_evsel = evlist__last(evlist);
 376
 377         /* Second event */
 378         err = parse_event(evlist, cycles);
 379         if (err) {
 380                 pr_debug("Failed to parse event %s\n", cycles);
 381                 goto out_err;
 382         }
 383
 384         cycles_evsel = evlist__last(evlist);
 385
 386         /* Third event */
 387         if (!evlist__can_select_event(evlist, sched_switch)) {
 388                 pr_debug("No sched_switch\n");
 389                 err = 0;
 390                 goto out;
 391         }
 392
 393         switch_evsel = evlist__add_sched_switch(evlist, true);
 394         if (IS_ERR(switch_evsel)) {
 395                 err = PTR_ERR(switch_evsel);
 396                 pr_debug("Failed to create event %s\n", sched_switch);
 397                 goto out_err;
 398         }
 399
 400         switch_evsel->immediate = true;
 401
 402         /* Test moving an event to the front */
 403         if (cycles_evsel == evlist__first(evlist)) {
 404                 pr_debug("cycles event already at front");
 405                 goto out_err;
 406         }
 407         evlist__to_front(evlist, cycles_evsel);
 408         if (cycles_evsel != evlist__first(evlist)) {
 409                 pr_debug("Failed to move cycles event to front");
 410                 goto out_err;
 411         }
 412
 413         evsel__set_sample_bit(cycles_evsel, CPU);
 414         evsel__set_sample_bit(cycles_evsel, TIME);
 415
 416         /* Fourth event */
 417         err = parse_event(evlist, "dummy:u");
 418         if (err) {
 419                 pr_debug("Failed to parse event dummy:u\n");
 420                 goto out_err;
 421         }
 422
 423         tracking_evsel = evlist__last(evlist);
 424
 425         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         evsel__set_sample_bit(tracking_evsel, TIME);
 431
 432         /* Config events */
 433         evlist__config(evlist, &opts, NULL);
 434
 435         /* Check moved event is still at the front */
 436         if (cycles_evsel != 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 = evlist__mmap(evlist, UINT_MAX);
 464         if (err) {
 465                 pr_debug("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         }
 576         perf_cpu_map__put(cpus);
 577         perf_thread_map__put(threads);
 578
 579         return err;
 580
 581 out_err:
 582         err = -1;
 583         goto out;
 584 }
 585
 586 DEFINE_SUITE("Track with sched_switch", switch_tracking);