tools/perf/tests/task-exit.c

   1 #include "evlist.h"
   2 #include "evsel.h"
   3 #include "thread_map.h"
   4 #include "cpumap.h"
   5 #include "tests.h"
   6
   7 #include <signal.h>
   8
   9 static int exited;
  10 static int nr_exit;
  11
  12 static void sig_handler(int sig __maybe_unused)
  13 {
  14         exited = 1;
  15 }
  16
  17 /*
  18  * perf_evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
  19  * we asked by setting its exec_error to this handler.
  20  */
  21 static void workload_exec_failed_signal(int signo __maybe_unused,
  22                                         siginfo_t *info __maybe_unused,
  23                                         void *ucontext __maybe_unused)
  24 {
  25         exited  = 1;
  26         nr_exit = -1;
  27 }
  28
  29 /*
  30  * This test will start a workload that does nothing then it checks
  31  * if the number of exit event reported by the kernel is 1 or not
  32  * in order to check the kernel returns correct number of event.
  33  */
  34 int test__task_exit(void)
  35 {
  36         int err = -1;
  37         union perf_event *event;
  38         struct perf_evsel *evsel;
  39         struct perf_evlist *evlist;
  40         struct target target = {
  41                 .uid            = UINT_MAX,
  42                 .uses_mmap      = true,
  43         };
  44         const char *argv[] = { "true", NULL };
  45
  46         signal(SIGCHLD, sig_handler);
  47
  48         evlist = perf_evlist__new_default();
  49         if (evlist == NULL) {
  50                 pr_debug("perf_evlist__new_default\n");
  51                 return -1;
  52         }
  53
  54         /*
  55          * Create maps of threads and cpus to monitor. In this case
  56          * we start with all threads and cpus (-1, -1) but then in
  57          * perf_evlist__prepare_workload we'll fill in the only thread
  58          * we're monitoring, the one forked there.
  59          */
  60         evlist->cpus = cpu_map__dummy_new();
  61         evlist->threads = thread_map__new_by_tid(-1);
  62         if (!evlist->cpus || !evlist->threads) {
  63                 err = -ENOMEM;
  64                 pr_debug("Not enough memory to create thread/cpu maps\n");
  65                 goto out_delete_evlist;
  66         }
  67
  68         err = perf_evlist__prepare_workload(evlist, &target, argv, false,
  69                                             workload_exec_failed_signal);
  70         if (err < 0) {
  71                 pr_debug("Couldn't run the workload!\n");
  72                 goto out_delete_evlist;
  73         }
  74
  75         evsel = perf_evlist__first(evlist);
  76         evsel->attr.task = 1;
  77         evsel->attr.sample_freq = 0;
  78         evsel->attr.inherit = 0;
  79         evsel->attr.watermark = 0;
  80         evsel->attr.wakeup_events = 1;
  81         evsel->attr.exclude_kernel = 1;
  82
  83         err = perf_evlist__open(evlist);
  84         if (err < 0) {
  85                 pr_debug("Couldn't open the evlist: %s\n", strerror(-err));
  86                 goto out_delete_evlist;
  87         }
  88
  89         if (perf_evlist__mmap(evlist, 128, true) < 0) {
  90                 pr_debug("failed to mmap events: %d (%s)\n", errno,
  91                          strerror(errno));
  92                 goto out_delete_evlist;
  93         }
  94
  95         perf_evlist__start_workload(evlist);
  96
  97 retry:
  98         while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
  99                 if (event->header.type == PERF_RECORD_EXIT)
 100                         nr_exit++;
 101
 102                 perf_evlist__mmap_consume(evlist, 0);
 103         }
 104
 105         if (!exited || !nr_exit) {
 106                 poll(evlist->pollfd, evlist->nr_fds, -1);
 107                 goto retry;
 108         }
 109
 110         if (nr_exit != 1) {
 111                 pr_debug("received %d EXIT records\n", nr_exit);
 112                 err = -1;
 113         }
 114
 115 out_delete_evlist:
 116         perf_evlist__delete(evlist);
 117         return err;
 118 }