linux/tools/perf/tests/switch-tracking.c
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   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
  23static 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
  61struct 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
  72static 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
  90static 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
 123static 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
 173static 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
 207struct event_node {
 208        struct list_head list;
 209        union perf_event *event;
 210        u64 event_time;
 211};
 212
 213static 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
 242static 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
 253static 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
 262static 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;
 308out_free:
 309        pr_debug("%u events recorded\n", cnt);
 310        free(events_array);
 311out_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 */
 324int test__switch_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
 325{
 326        const char *sched_switch = "sched:sched_switch";
 327        struct switch_tracking switch_tracking = { .tids = NULL, };
 328        struct record_opts opts = {
 329                .mmap_pages          = UINT_MAX,
 330                .user_freq           = UINT_MAX,
 331                .user_interval       = ULLONG_MAX,
 332                .freq                = 4000,
 333                .target              = {
 334                        .uses_mmap   = true,
 335                },
 336        };
 337        struct perf_thread_map *threads = NULL;
 338        struct perf_cpu_map *cpus = NULL;
 339        struct evlist *evlist = NULL;
 340        struct evsel *evsel, *cpu_clocks_evsel, *cycles_evsel;
 341        struct evsel *switch_evsel, *tracking_evsel;
 342        const char *comm;
 343        int err = -1;
 344
 345        threads = thread_map__new(-1, getpid(), UINT_MAX);
 346        if (!threads) {
 347                pr_debug("thread_map__new failed!\n");
 348                goto out_err;
 349        }
 350
 351        cpus = perf_cpu_map__new(NULL);
 352        if (!cpus) {
 353                pr_debug("perf_cpu_map__new failed!\n");
 354                goto out_err;
 355        }
 356
 357        evlist = evlist__new();
 358        if (!evlist) {
 359                pr_debug("evlist__new failed!\n");
 360                goto out_err;
 361        }
 362
 363        perf_evlist__set_maps(&evlist->core, cpus, threads);
 364
 365        /* First event */
 366        err = parse_events(evlist, "cpu-clock:u", NULL);
 367        if (err) {
 368                pr_debug("Failed to parse event dummy:u\n");
 369                goto out_err;
 370        }
 371
 372        cpu_clocks_evsel = evlist__last(evlist);
 373
 374        /* Second event */
 375        if (perf_pmu__has_hybrid())
 376                err = parse_events(evlist, "cpu_core/cycles/u", NULL);
 377        else
 378                err = parse_events(evlist, "cycles:u", NULL);
 379        if (err) {
 380                pr_debug("Failed to parse event cycles:u\n");
 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        err = parse_events(evlist, sched_switch, NULL);
 394        if (err) {
 395                pr_debug("Failed to parse event %s\n", sched_switch);
 396                goto out_err;
 397        }
 398
 399        switch_evsel = evlist__last(evlist);
 400
 401        evsel__set_sample_bit(switch_evsel, CPU);
 402        evsel__set_sample_bit(switch_evsel, TIME);
 403
 404        switch_evsel->core.system_wide = true;
 405        switch_evsel->no_aux_samples = true;
 406        switch_evsel->immediate = true;
 407
 408        /* Test moving an event to the front */
 409        if (cycles_evsel == evlist__first(evlist)) {
 410                pr_debug("cycles event already at front");
 411                goto out_err;
 412        }
 413        evlist__to_front(evlist, cycles_evsel);
 414        if (cycles_evsel != evlist__first(evlist)) {
 415                pr_debug("Failed to move cycles event to front");
 416                goto out_err;
 417        }
 418
 419        evsel__set_sample_bit(cycles_evsel, CPU);
 420        evsel__set_sample_bit(cycles_evsel, TIME);
 421
 422        /* Fourth event */
 423        err = parse_events(evlist, "dummy:u", NULL);
 424        if (err) {
 425                pr_debug("Failed to parse event dummy:u\n");
 426                goto out_err;
 427        }
 428
 429        tracking_evsel = evlist__last(evlist);
 430
 431        evlist__set_tracking_event(evlist, tracking_evsel);
 432
 433        tracking_evsel->core.attr.freq = 0;
 434        tracking_evsel->core.attr.sample_period = 1;
 435
 436        evsel__set_sample_bit(tracking_evsel, TIME);
 437
 438        /* Config events */
 439        evlist__config(evlist, &opts, NULL);
 440
 441        /* Check moved event is still at the front */
 442        if (cycles_evsel != evlist__first(evlist)) {
 443                pr_debug("Front event no longer at front");
 444                goto out_err;
 445        }
 446
 447        /* Check tracking event is tracking */
 448        if (!tracking_evsel->core.attr.mmap || !tracking_evsel->core.attr.comm) {
 449                pr_debug("Tracking event not tracking\n");
 450                goto out_err;
 451        }
 452
 453        /* Check non-tracking events are not tracking */
 454        evlist__for_each_entry(evlist, evsel) {
 455                if (evsel != tracking_evsel) {
 456                        if (evsel->core.attr.mmap || evsel->core.attr.comm) {
 457                                pr_debug("Non-tracking event is tracking\n");
 458                                goto out_err;
 459                        }
 460                }
 461        }
 462
 463        if (evlist__open(evlist) < 0) {
 464                pr_debug("Not supported\n");
 465                err = 0;
 466                goto out;
 467        }
 468
 469        err = evlist__mmap(evlist, UINT_MAX);
 470        if (err) {
 471                pr_debug("evlist__mmap failed!\n");
 472                goto out_err;
 473        }
 474
 475        evlist__enable(evlist);
 476
 477        err = evsel__disable(cpu_clocks_evsel);
 478        if (err) {
 479                pr_debug("perf_evlist__disable_event failed!\n");
 480                goto out_err;
 481        }
 482
 483        err = spin_sleep();
 484        if (err) {
 485                pr_debug("spin_sleep failed!\n");
 486                goto out_err;
 487        }
 488
 489        comm = "Test COMM 1";
 490        err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 491        if (err) {
 492                pr_debug("PR_SET_NAME failed!\n");
 493                goto out_err;
 494        }
 495
 496        err = evsel__disable(cycles_evsel);
 497        if (err) {
 498                pr_debug("perf_evlist__disable_event failed!\n");
 499                goto out_err;
 500        }
 501
 502        comm = "Test COMM 2";
 503        err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 504        if (err) {
 505                pr_debug("PR_SET_NAME failed!\n");
 506                goto out_err;
 507        }
 508
 509        err = spin_sleep();
 510        if (err) {
 511                pr_debug("spin_sleep failed!\n");
 512                goto out_err;
 513        }
 514
 515        comm = "Test COMM 3";
 516        err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 517        if (err) {
 518                pr_debug("PR_SET_NAME failed!\n");
 519                goto out_err;
 520        }
 521
 522        err = evsel__enable(cycles_evsel);
 523        if (err) {
 524                pr_debug("perf_evlist__disable_event failed!\n");
 525                goto out_err;
 526        }
 527
 528        comm = "Test COMM 4";
 529        err = prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0);
 530        if (err) {
 531                pr_debug("PR_SET_NAME failed!\n");
 532                goto out_err;
 533        }
 534
 535        err = spin_sleep();
 536        if (err) {
 537                pr_debug("spin_sleep failed!\n");
 538                goto out_err;
 539        }
 540
 541        evlist__disable(evlist);
 542
 543        switch_tracking.switch_evsel = switch_evsel;
 544        switch_tracking.cycles_evsel = cycles_evsel;
 545
 546        err = process_events(evlist, &switch_tracking);
 547
 548        zfree(&switch_tracking.tids);
 549
 550        if (err)
 551                goto out_err;
 552
 553        /* Check all 4 comm events were seen i.e. that evsel->tracking works */
 554        if (!switch_tracking.comm_seen[0] || !switch_tracking.comm_seen[1] ||
 555            !switch_tracking.comm_seen[2] || !switch_tracking.comm_seen[3]) {
 556                pr_debug("Missing comm events\n");
 557                goto out_err;
 558        }
 559
 560        /* Check cycles event got enabled */
 561        if (!switch_tracking.cycles_before_comm_1) {
 562                pr_debug("Missing cycles events\n");
 563                goto out_err;
 564        }
 565
 566        /* Check cycles event got disabled */
 567        if (switch_tracking.cycles_between_comm_2_and_comm_3) {
 568                pr_debug("cycles events even though event was disabled\n");
 569                goto out_err;
 570        }
 571
 572        /* Check cycles event got enabled again */
 573        if (!switch_tracking.cycles_after_comm_4) {
 574                pr_debug("Missing cycles events\n");
 575                goto out_err;
 576        }
 577out:
 578        if (evlist) {
 579                evlist__disable(evlist);
 580                evlist__delete(evlist);
 581        }
 582        perf_cpu_map__put(cpus);
 583        perf_thread_map__put(threads);
 584
 585        return err;
 586
 587out_err:
 588        err = -1;
 589        goto out;
 590}
 591
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