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(int subtest __maybe_unused)
  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         char sbuf[STRERR_BUFSIZE];
  46         struct cpu_map *cpus;
  47         struct thread_map *threads;
  48
  49         signal(SIGCHLD, sig_handler);
  50
  51         evlist = perf_evlist__new_default();
  52         if (evlist == NULL) {
  53                 pr_debug("perf_evlist__new_default\n");
  54                 return -1;
  55         }
  56
  57         /*
  58          * Create maps of threads and cpus to monitor. In this case
  59          * we start with all threads and cpus (-1, -1) but then in
  60          * perf_evlist__prepare_workload we'll fill in the only thread
  61          * we're monitoring, the one forked there.
  62          */
  63         cpus = cpu_map__dummy_new();
  64         threads = thread_map__new_by_tid(-1);
  65         if (!cpus || !threads) {
  66                 err = -ENOMEM;
  67                 pr_debug("Not enough memory to create thread/cpu maps\n");
  68                 goto out_free_maps;
  69         }
  70
  71         perf_evlist__set_maps(evlist, cpus, threads);
  72
  73         cpus    = NULL;
  74         threads = NULL;
  75
  76         err = perf_evlist__prepare_workload(evlist, &target, argv, false,
  77                                             workload_exec_failed_signal);
  78         if (err < 0) {
  79                 pr_debug("Couldn't run the workload!\n");
  80                 goto out_delete_evlist;
  81         }
  82
  83         evsel = perf_evlist__first(evlist);
  84         evsel->attr.task = 1;
  85         evsel->attr.sample_freq = 0;
  86         evsel->attr.inherit = 0;
  87         evsel->attr.watermark = 0;
  88         evsel->attr.wakeup_events = 1;
  89         evsel->attr.exclude_kernel = 1;
  90
  91         err = perf_evlist__open(evlist);
  92         if (err < 0) {
  93                 pr_debug("Couldn't open the evlist: %s\n",
  94                          str_error_r(-err, sbuf, sizeof(sbuf)));
  95                 goto out_delete_evlist;
  96         }
  97
  98         if (perf_evlist__mmap(evlist, 128, true) < 0) {
  99                 pr_debug("failed to mmap events: %d (%s)\n", errno,
 100                          str_error_r(errno, sbuf, sizeof(sbuf)));
 101                 goto out_delete_evlist;
 102         }
 103
 104         perf_evlist__start_workload(evlist);
 105
 106 retry:
 107         while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
 108                 if (event->header.type == PERF_RECORD_EXIT)
 109                         nr_exit++;
 110
 111                 perf_evlist__mmap_consume(evlist, 0);
 112         }
 113
 114         if (!exited || !nr_exit) {
 115                 perf_evlist__poll(evlist, -1);
 116                 goto retry;
 117         }
 118
 119         if (nr_exit != 1) {
 120                 pr_debug("received %d EXIT records\n", nr_exit);
 121                 err = -1;
 122         }
 123
 124 out_free_maps:
 125         cpu_map__put(cpus);
 126         thread_map__put(threads);
 127 out_delete_evlist:
 128         perf_evlist__delete(evlist);
 129         return err;
 130 }