tools/perf/tests/keep-tracking.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/types.h>
   3 #include <unistd.h>
   4 #include <sys/prctl.h>
   5
   6 #include "parse-events.h"
   7 #include "evlist.h"
   8 #include "evsel.h"
   9 #include "thread_map.h"
  10 #include "cpumap.h"
  11 #include "tests.h"
  12
  13 #define CHECK__(x) {                            \
  14         while ((x) < 0) {                       \
  15                 pr_debug(#x " failed!\n");      \
  16                 goto out_err;                   \
  17         }                                       \
  18 }
  19
  20 #define CHECK_NOT_NULL__(x) {                   \
  21         while ((x) == NULL) {                   \
  22                 pr_debug(#x " failed!\n");      \
  23                 goto out_err;                   \
  24         }                                       \
  25 }
  26
  27 static int find_comm(struct perf_evlist *evlist, const char *comm)
  28 {
  29         union perf_event *event;
  30         struct perf_mmap *md;
  31         int i, found;
  32
  33         found = 0;
  34         for (i = 0; i < evlist->nr_mmaps; i++) {
  35                 md = &evlist->mmap[i];
  36                 if (perf_mmap__read_init(md) < 0)
  37                         continue;
  38                 while ((event = perf_mmap__read_event(md)) != NULL) {
  39                         if (event->header.type == PERF_RECORD_COMM &&
  40                             (pid_t)event->comm.pid == getpid() &&
  41                             (pid_t)event->comm.tid == getpid() &&
  42                             strcmp(event->comm.comm, comm) == 0)
  43                                 found += 1;
  44                         perf_mmap__consume(md);
  45                 }
  46                 perf_mmap__read_done(md);
  47         }
  48         return found;
  49 }
  50
  51 /**
  52  * test__keep_tracking - test using a dummy software event to keep tracking.
  53  *
  54  * This function implements a test that checks that tracking events continue
  55  * when an event is disabled but a dummy software event is not disabled.  If the
  56  * test passes %0 is returned, otherwise %-1 is returned.
  57  */
  58 int test__keep_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
  59 {
  60         struct record_opts opts = {
  61                 .mmap_pages          = UINT_MAX,
  62                 .user_freq           = UINT_MAX,
  63                 .user_interval       = ULLONG_MAX,
  64                 .target              = {
  65                         .uses_mmap   = true,
  66                 },
  67         };
  68         struct thread_map *threads = NULL;
  69         struct cpu_map *cpus = NULL;
  70         struct perf_evlist *evlist = NULL;
  71         struct perf_evsel *evsel = NULL;
  72         int found, err = -1;
  73         const char *comm;
  74
  75         threads = thread_map__new(-1, getpid(), UINT_MAX);
  76         CHECK_NOT_NULL__(threads);
  77
  78         cpus = cpu_map__new(NULL);
  79         CHECK_NOT_NULL__(cpus);
  80
  81         evlist = perf_evlist__new();
  82         CHECK_NOT_NULL__(evlist);
  83
  84         perf_evlist__set_maps(evlist, cpus, threads);
  85
  86         CHECK__(parse_events(evlist, "dummy:u", NULL));
  87         CHECK__(parse_events(evlist, "cycles:u", NULL));
  88
  89         perf_evlist__config(evlist, &opts, NULL);
  90
  91         evsel = perf_evlist__first(evlist);
  92
  93         evsel->attr.comm = 1;
  94         evsel->attr.disabled = 1;
  95         evsel->attr.enable_on_exec = 0;
  96
  97         if (perf_evlist__open(evlist) < 0) {
  98                 pr_debug("Unable to open dummy and cycles event\n");
  99                 err = TEST_SKIP;
 100                 goto out_err;
 101         }
 102
 103         CHECK__(perf_evlist__mmap(evlist, UINT_MAX));
 104
 105         /*
 106          * First, test that a 'comm' event can be found when the event is
 107          * enabled.
 108          */
 109
 110         perf_evlist__enable(evlist);
 111
 112         comm = "Test COMM 1";
 113         CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
 114
 115         perf_evlist__disable(evlist);
 116
 117         found = find_comm(evlist, comm);
 118         if (found != 1) {
 119                 pr_debug("First time, failed to find tracking event.\n");
 120                 goto out_err;
 121         }
 122
 123         /*
 124          * Secondly, test that a 'comm' event can be found when the event is
 125          * disabled with the dummy event still enabled.
 126          */
 127
 128         perf_evlist__enable(evlist);
 129
 130         evsel = perf_evlist__last(evlist);
 131
 132         CHECK__(perf_evsel__disable(evsel));
 133
 134         comm = "Test COMM 2";
 135         CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
 136
 137         perf_evlist__disable(evlist);
 138
 139         found = find_comm(evlist, comm);
 140         if (found != 1) {
 141                 pr_debug("Seconf time, failed to find tracking event.\n");
 142                 goto out_err;
 143         }
 144
 145         err = 0;
 146
 147 out_err:
 148         if (evlist) {
 149                 perf_evlist__disable(evlist);
 150                 perf_evlist__delete(evlist);
 151         } else {
 152                 cpu_map__put(cpus);
 153                 thread_map__put(threads);
 154         }
 155
 156         return err;
 157 }