tools/perf/tests/task-exit.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include "evlist.h"
   3 #include "evsel.h"
   4 #include "thread_map.h"
   5 #include "cpumap.h"
   6 #include "tests.h"
   7
   8 #include <errno.h>
   9 #include <signal.h>
  10
  11 static int exited;
  12 static int nr_exit;
  13
  14 static void sig_handler(int sig __maybe_unused)
  15 {
  16         exited = 1;
  17 }
  18
  19 /*
  20  * perf_evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
  21  * we asked by setting its exec_error to this handler.
  22  */
  23 static void workload_exec_failed_signal(int signo __maybe_unused,
  24                                         siginfo_t *info __maybe_unused,
  25                                         void *ucontext __maybe_unused)
  26 {
  27         exited  = 1;
  28         nr_exit = -1;
  29 }
  30
  31 /*
  32  * This test will start a workload that does nothing then it checks
  33  * if the number of exit event reported by the kernel is 1 or not
  34  * in order to check the kernel returns correct number of event.
  35  */
  36 int test__task_exit(struct test *test __maybe_unused, int subtest __maybe_unused)
  37 {
  38         int err = -1;
  39         union perf_event *event;
  40         struct perf_evsel *evsel;
  41         struct perf_evlist *evlist;
  42         struct target target = {
  43                 .uid            = UINT_MAX,
  44                 .uses_mmap      = true,
  45         };
  46         const char *argv[] = { "true", NULL };
  47         char sbuf[STRERR_BUFSIZE];
  48         struct cpu_map *cpus;
  49         struct thread_map *threads;
  50
  51         signal(SIGCHLD, sig_handler);
  52
  53         evlist = perf_evlist__new_default();
  54         if (evlist == NULL) {
  55                 pr_debug("perf_evlist__new_default\n");
  56                 return -1;
  57         }
  58
  59         /*
  60          * Create maps of threads and cpus to monitor. In this case
  61          * we start with all threads and cpus (-1, -1) but then in
  62          * perf_evlist__prepare_workload we'll fill in the only thread
  63          * we're monitoring, the one forked there.
  64          */
  65         cpus = cpu_map__dummy_new();
  66         threads = thread_map__new_by_tid(-1);
  67         if (!cpus || !threads) {
  68                 err = -ENOMEM;
  69                 pr_debug("Not enough memory to create thread/cpu maps\n");
  70                 goto out_free_maps;
  71         }
  72
  73         perf_evlist__set_maps(evlist, cpus, threads);
  74
  75         cpus    = NULL;
  76         threads = NULL;
  77
  78         err = perf_evlist__prepare_workload(evlist, &target, argv, false,
  79                                             workload_exec_failed_signal);
  80         if (err < 0) {
  81                 pr_debug("Couldn't run the workload!\n");
  82                 goto out_delete_evlist;
  83         }
  84
  85         evsel = perf_evlist__first(evlist);
  86         evsel->attr.task = 1;
  87         evsel->attr.sample_freq = 1;
  88         evsel->attr.inherit = 0;
  89         evsel->attr.watermark = 0;
  90         evsel->attr.wakeup_events = 1;
  91         evsel->attr.exclude_kernel = 1;
  92
  93         err = perf_evlist__open(evlist);
  94         if (err < 0) {
  95                 pr_debug("Couldn't open the evlist: %s\n",
  96                          str_error_r(-err, sbuf, sizeof(sbuf)));
  97                 goto out_delete_evlist;
  98         }
  99
 100         if (perf_evlist__mmap(evlist, 128, true) < 0) {
 101                 pr_debug("failed to mmap events: %d (%s)\n", errno,
 102                          str_error_r(errno, sbuf, sizeof(sbuf)));
 103                 goto out_delete_evlist;
 104         }
 105
 106         perf_evlist__start_workload(evlist);
 107
 108 retry:
 109         while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
 110                 if (event->header.type == PERF_RECORD_EXIT)
 111                         nr_exit++;
 112
 113                 perf_evlist__mmap_consume(evlist, 0);
 114         }
 115
 116         if (!exited || !nr_exit) {
 117                 perf_evlist__poll(evlist, -1);
 118                 goto retry;
 119         }
 120
 121         if (nr_exit != 1) {
 122                 pr_debug("received %d EXIT records\n", nr_exit);
 123                 err = -1;
 124         }
 125
 126 out_free_maps:
 127         cpu_map__put(cpus);
 128         thread_map__put(threads);
 129 out_delete_evlist:
 130         perf_evlist__delete(evlist);
 131         return err;
 132 }