tools/perf/tests/keep-tracking.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/types.h>
   3 #include <limits.h>
   4 #include <unistd.h>
   5 #include <sys/prctl.h>
   6 #include <perf/cpumap.h>
   7 #include <perf/evlist.h>
   8
   9 #include "debug.h"
  10 #include "parse-events.h"
  11 #include "evlist.h"
  12 #include "evsel.h"
  13 #include "record.h"
  14 #include "thread_map.h"
  15 #include "tests.h"
  16
  17 #define CHECK__(x) {                            \
  18         while ((x) < 0) {                       \
  19                 pr_debug(#x " failed!\n");      \
  20                 goto out_err;                   \
  21         }                                       \
  22 }
  23
  24 #define CHECK_NOT_NULL__(x) {                   \
  25         while ((x) == NULL) {                   \
  26                 pr_debug(#x " failed!\n");      \
  27                 goto out_err;                   \
  28         }                                       \
  29 }
  30
  31 static int find_comm(struct evlist *evlist, const char *comm)
  32 {
  33         union perf_event *event;
  34         struct mmap *md;
  35         int i, found;
  36
  37         found = 0;
  38         for (i = 0; i < evlist->nr_mmaps; i++) {
  39                 md = &evlist->mmap[i];
  40                 if (perf_mmap__read_init(md) < 0)
  41                         continue;
  42                 while ((event = perf_mmap__read_event(md)) != NULL) {
  43                         if (event->header.type == PERF_RECORD_COMM &&
  44                             (pid_t)event->comm.pid == getpid() &&
  45                             (pid_t)event->comm.tid == getpid() &&
  46                             strcmp(event->comm.comm, comm) == 0)
  47                                 found += 1;
  48                         perf_mmap__consume(md);
  49                 }
  50                 perf_mmap__read_done(md);
  51         }
  52         return found;
  53 }
  54
  55 /**
  56  * test__keep_tracking - test using a dummy software event to keep tracking.
  57  *
  58  * This function implements a test that checks that tracking events continue
  59  * when an event is disabled but a dummy software event is not disabled.  If the
  60  * test passes %0 is returned, otherwise %-1 is returned.
  61  */
  62 int test__keep_tracking(struct test *test __maybe_unused, int subtest __maybe_unused)
  63 {
  64         struct record_opts opts = {
  65                 .mmap_pages          = UINT_MAX,
  66                 .user_freq           = UINT_MAX,
  67                 .user_interval       = ULLONG_MAX,
  68                 .target              = {
  69                         .uses_mmap   = true,
  70                 },
  71         };
  72         struct perf_thread_map *threads = NULL;
  73         struct perf_cpu_map *cpus = NULL;
  74         struct evlist *evlist = NULL;
  75         struct evsel *evsel = NULL;
  76         int found, err = -1;
  77         const char *comm;
  78
  79         threads = thread_map__new(-1, getpid(), UINT_MAX);
  80         CHECK_NOT_NULL__(threads);
  81
  82         cpus = perf_cpu_map__new(NULL);
  83         CHECK_NOT_NULL__(cpus);
  84
  85         evlist = evlist__new();
  86         CHECK_NOT_NULL__(evlist);
  87
  88         perf_evlist__set_maps(&evlist->core, cpus, threads);
  89
  90         CHECK__(parse_events(evlist, "dummy:u", NULL));
  91         CHECK__(parse_events(evlist, "cycles:u", NULL));
  92
  93         perf_evlist__config(evlist, &opts, NULL);
  94
  95         evsel = perf_evlist__first(evlist);
  96
  97         evsel->core.attr.comm = 1;
  98         evsel->core.attr.disabled = 1;
  99         evsel->core.attr.enable_on_exec = 0;
 100
 101         if (evlist__open(evlist) < 0) {
 102                 pr_debug("Unable to open dummy and cycles event\n");
 103                 err = TEST_SKIP;
 104                 goto out_err;
 105         }
 106
 107         CHECK__(evlist__mmap(evlist, UINT_MAX));
 108
 109         /*
 110          * First, test that a 'comm' event can be found when the event is
 111          * enabled.
 112          */
 113
 114         evlist__enable(evlist);
 115
 116         comm = "Test COMM 1";
 117         CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
 118
 119         evlist__disable(evlist);
 120
 121         found = find_comm(evlist, comm);
 122         if (found != 1) {
 123                 pr_debug("First time, failed to find tracking event.\n");
 124                 goto out_err;
 125         }
 126
 127         /*
 128          * Secondly, test that a 'comm' event can be found when the event is
 129          * disabled with the dummy event still enabled.
 130          */
 131
 132         evlist__enable(evlist);
 133
 134         evsel = perf_evlist__last(evlist);
 135
 136         CHECK__(evsel__disable(evsel));
 137
 138         comm = "Test COMM 2";
 139         CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
 140
 141         evlist__disable(evlist);
 142
 143         found = find_comm(evlist, comm);
 144         if (found != 1) {
 145                 pr_debug("Second time, failed to find tracking event.\n");
 146                 goto out_err;
 147         }
 148
 149         err = 0;
 150
 151 out_err:
 152         if (evlist) {
 153                 evlist__disable(evlist);
 154                 evlist__delete(evlist);
 155         } else {
 156                 perf_cpu_map__put(cpus);
 157                 perf_thread_map__put(threads);
 158         }
 159
 160         return err;
 161 }