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 #include <perf/mmap.h>
   9
  10 #include "debug.h"
  11 #include "parse-events.h"
  12 #include "evlist.h"
  13 #include "evsel.h"
  14 #include "record.h"
  15 #include "thread_map.h"
  16 #include "tests.h"
  17 #include "util/mmap.h"
  18
  19 #define CHECK__(x) {                            \
  20         while ((x) < 0) {                       \
  21                 pr_debug(#x " failed!\n");      \
  22                 goto out_err;                   \
  23         }                                       \
  24 }
  25
  26 #define CHECK_NOT_NULL__(x) {                   \
  27         while ((x) == NULL) {                   \
  28                 pr_debug(#x " failed!\n");      \
  29                 goto out_err;                   \
  30         }                                       \
  31 }
  32
  33 static int find_comm(struct evlist *evlist, const char *comm)
  34 {
  35         union perf_event *event;
  36         struct mmap *md;
  37         int i, found;
  38
  39         found = 0;
  40         for (i = 0; i < evlist->core.nr_mmaps; i++) {
  41                 md = &evlist->mmap[i];
  42                 if (perf_mmap__read_init(&md->core) < 0)
  43                         continue;
  44                 while ((event = perf_mmap__read_event(&md->core)) != NULL) {
  45                         if (event->header.type == PERF_RECORD_COMM &&
  46                             (pid_t)event->comm.pid == getpid() &&
  47                             (pid_t)event->comm.tid == getpid() &&
  48                             strcmp(event->comm.comm, comm) == 0)
  49                                 found += 1;
  50                         perf_mmap__consume(&md->core);
  51                 }
  52                 perf_mmap__read_done(&md->core);
  53         }
  54         return found;
  55 }
  56
  57 /**
  58  * test__keep_tracking - test using a dummy software event to keep tracking.
  59  *
  60  * This function implements a test that checks that tracking events continue
  61  * when an event is disabled but a dummy software event is not disabled.  If the
  62  * test passes %0 is returned, otherwise %-1 is returned.
  63  */
  64 static int test__keep_tracking(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
  65 {
  66         struct record_opts opts = {
  67                 .mmap_pages          = UINT_MAX,
  68                 .user_freq           = UINT_MAX,
  69                 .user_interval       = ULLONG_MAX,
  70                 .target              = {
  71                         .uses_mmap   = true,
  72                 },
  73         };
  74         struct perf_thread_map *threads = NULL;
  75         struct perf_cpu_map *cpus = NULL;
  76         struct evlist *evlist = NULL;
  77         struct evsel *evsel = NULL;
  78         int found, err = -1;
  79         const char *comm;
  80
  81         threads = thread_map__new(-1, getpid(), UINT_MAX);
  82         CHECK_NOT_NULL__(threads);
  83
  84         cpus = perf_cpu_map__new_online_cpus();
  85         CHECK_NOT_NULL__(cpus);
  86
  87         evlist = evlist__new();
  88         CHECK_NOT_NULL__(evlist);
  89
  90         perf_evlist__set_maps(&evlist->core, cpus, threads);
  91
  92         CHECK__(parse_event(evlist, "dummy:u"));
  93         CHECK__(parse_event(evlist, "cycles:u"));
  94
  95         evlist__config(evlist, &opts, NULL);
  96
  97         evsel = evlist__first(evlist);
  98
  99         evsel->core.attr.comm = 1;
 100         evsel->core.attr.disabled = 1;
 101         evsel->core.attr.enable_on_exec = 0;
 102
 103         if (evlist__open(evlist) < 0) {
 104                 pr_debug("Unable to open dummy and cycles event\n");
 105                 err = TEST_SKIP;
 106                 goto out_err;
 107         }
 108
 109         CHECK__(evlist__mmap(evlist, UINT_MAX));
 110
 111         /*
 112          * First, test that a 'comm' event can be found when the event is
 113          * enabled.
 114          */
 115
 116         evlist__enable(evlist);
 117
 118         comm = "Test COMM 1";
 119         CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
 120
 121         evlist__disable(evlist);
 122
 123         found = find_comm(evlist, comm);
 124         if (found != 1) {
 125                 pr_debug("First time, failed to find tracking event.\n");
 126                 goto out_err;
 127         }
 128
 129         /*
 130          * Secondly, test that a 'comm' event can be found when the event is
 131          * disabled with the dummy event still enabled.
 132          */
 133
 134         evlist__enable(evlist);
 135
 136         evsel = evlist__last(evlist);
 137
 138         CHECK__(evsel__disable(evsel));
 139
 140         comm = "Test COMM 2";
 141         CHECK__(prctl(PR_SET_NAME, (unsigned long)comm, 0, 0, 0));
 142
 143         evlist__disable(evlist);
 144
 145         found = find_comm(evlist, comm);
 146         if (found != 1) {
 147                 pr_debug("Second time, failed to find tracking event.\n");
 148                 goto out_err;
 149         }
 150
 151         err = 0;
 152
 153 out_err:
 154         if (evlist) {
 155                 evlist__disable(evlist);
 156                 evlist__delete(evlist);
 157         }
 158         perf_cpu_map__put(cpus);
 159         perf_thread_map__put(threads);
 160
 161         return err;
 162 }
 163
 164 DEFINE_SUITE("Use a dummy software event to keep tracking", keep_tracking);