root/tools/perf/tests/keep-tracking.c

DEFINITIONS

1. find_comm
2. test__keep_tracking

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