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