root/tools/perf/tests/task-exit.c

DEFINITIONS

1. sig_handler
2. workload_exec_failed_signal
3. test__task_exit

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include "debug.h"
   3 #include "evlist.h"
   4 #include "evsel.h"
   5 #include "target.h"
   6 #include "thread_map.h"
   7 #include "tests.h"
   8 #include "util/mmap.h"
   9 
  10 #include <errno.h>
  11 #include <signal.h>
  12 #include <linux/string.h>
  13 #include <perf/cpumap.h>
  14 #include <perf/evlist.h>
  15 
  16 static int exited;
  17 static int nr_exit;
  18 
  19 static void sig_handler(int sig __maybe_unused)
  20 {
  21         exited = 1;
  22 }
  23 
  24 /*
  25  * perf_evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
  26  * we asked by setting its exec_error to this handler.
  27  */
  28 static void workload_exec_failed_signal(int signo __maybe_unused,
  29                                         siginfo_t *info __maybe_unused,
  30                                         void *ucontext __maybe_unused)
  31 {
  32         exited  = 1;
  33         nr_exit = -1;
  34 }
  35 
  36 /*
  37  * This test will start a workload that does nothing then it checks
  38  * if the number of exit event reported by the kernel is 1 or not
  39  * in order to check the kernel returns correct number of event.
  40  */
  41 int test__task_exit(struct test *test __maybe_unused, int subtest __maybe_unused)
  42 {
  43         int err = -1;
  44         union perf_event *event;
  45         struct evsel *evsel;
  46         struct evlist *evlist;
  47         struct target target = {
  48                 .uid            = UINT_MAX,
  49                 .uses_mmap      = true,
  50         };
  51         const char *argv[] = { "true", NULL };
  52         char sbuf[STRERR_BUFSIZE];
  53         struct perf_cpu_map *cpus;
  54         struct perf_thread_map *threads;
  55         struct mmap *md;
  56         int retry_count = 0;
  57 
  58         signal(SIGCHLD, sig_handler);
  59 
  60         evlist = perf_evlist__new_default();
  61         if (evlist == NULL) {
  62                 pr_debug("perf_evlist__new_default\n");
  63                 return -1;
  64         }
  65 
  66         /*
  67          * Create maps of threads and cpus to monitor. In this case
  68          * we start with all threads and cpus (-1, -1) but then in
  69          * perf_evlist__prepare_workload we'll fill in the only thread
  70          * we're monitoring, the one forked there.
  71          */
  72         cpus = perf_cpu_map__dummy_new();
  73         threads = thread_map__new_by_tid(-1);
  74         if (!cpus || !threads) {
  75                 err = -ENOMEM;
  76                 pr_debug("Not enough memory to create thread/cpu maps\n");
  77                 goto out_free_maps;
  78         }
  79 
  80         perf_evlist__set_maps(&evlist->core, cpus, threads);
  81 
  82         cpus    = NULL;
  83         threads = NULL;
  84 
  85         err = perf_evlist__prepare_workload(evlist, &target, argv, false,
  86                                             workload_exec_failed_signal);
  87         if (err < 0) {
  88                 pr_debug("Couldn't run the workload!\n");
  89                 goto out_delete_evlist;
  90         }
  91 
  92         evsel = evlist__first(evlist);
  93         evsel->core.attr.task = 1;
  94 #ifdef __s390x__
  95         evsel->core.attr.sample_freq = 1000000;
  96 #else
  97         evsel->core.attr.sample_freq = 1;
  98 #endif
  99         evsel->core.attr.inherit = 0;
 100         evsel->core.attr.watermark = 0;
 101         evsel->core.attr.wakeup_events = 1;
 102         evsel->core.attr.exclude_kernel = 1;
 103 
 104         err = evlist__open(evlist);
 105         if (err < 0) {
 106                 pr_debug("Couldn't open the evlist: %s\n",
 107                          str_error_r(-err, sbuf, sizeof(sbuf)));
 108                 goto out_delete_evlist;
 109         }
 110 
 111         if (evlist__mmap(evlist, 128) < 0) {
 112                 pr_debug("failed to mmap events: %d (%s)\n", errno,
 113                          str_error_r(errno, sbuf, sizeof(sbuf)));
 114                 err = -1;
 115                 goto out_delete_evlist;
 116         }
 117 
 118         perf_evlist__start_workload(evlist);
 119 
 120 retry:
 121         md = &evlist->mmap[0];
 122         if (perf_mmap__read_init(md) < 0)
 123                 goto out_init;
 124 
 125         while ((event = perf_mmap__read_event(md)) != NULL) {
 126                 if (event->header.type == PERF_RECORD_EXIT)
 127                         nr_exit++;
 128 
 129                 perf_mmap__consume(md);
 130         }
 131         perf_mmap__read_done(md);
 132 
 133 out_init:
 134         if (!exited || !nr_exit) {
 135                 evlist__poll(evlist, -1);
 136 
 137                 if (retry_count++ > 1000) {
 138                         pr_debug("Failed after retrying 1000 times\n");
 139                         err = -1;
 140                         goto out_free_maps;
 141                 }
 142 
 143                 goto retry;
 144         }
 145 
 146         if (nr_exit != 1) {
 147                 pr_debug("received %d EXIT records\n", nr_exit);
 148                 err = -1;
 149         }
 150 
 151 out_free_maps:
 152         perf_cpu_map__put(cpus);
 153         perf_thread_map__put(threads);
 154 out_delete_evlist:
 155         evlist__delete(evlist);
 156         return err;
 157 }