LXR linux/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
  11static int exited;
  12static int nr_exit;
  13
  14static 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 */
  23static 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 */
  36int 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#ifdef __s390x__
  88        evsel->attr.sample_freq = 1000000;
  89#else
  90        evsel->attr.sample_freq = 1;
  91#endif
  92        evsel->attr.inherit = 0;
  93        evsel->attr.watermark = 0;
  94        evsel->attr.wakeup_events = 1;
  95        evsel->attr.exclude_kernel = 1;
  96
  97        err = perf_evlist__open(evlist);
  98        if (err < 0) {
  99                pr_debug("Couldn't open the evlist: %s\n",
 100                         str_error_r(-err, sbuf, sizeof(sbuf)));
 101                goto out_delete_evlist;
 102        }
 103
 104        if (perf_evlist__mmap(evlist, 128) < 0) {
 105                pr_debug("failed to mmap events: %d (%s)\n", errno,
 106                         str_error_r(errno, sbuf, sizeof(sbuf)));
 107                goto out_delete_evlist;
 108        }
 109
 110        perf_evlist__start_workload(evlist);
 111
 112retry:
 113        while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
 114                if (event->header.type == PERF_RECORD_EXIT)
 115                        nr_exit++;
 116
 117                perf_evlist__mmap_consume(evlist, 0);
 118        }
 119
 120        if (!exited || !nr_exit) {
 121                perf_evlist__poll(evlist, -1);
 122                goto retry;
 123        }
 124
 125        if (nr_exit != 1) {
 126                pr_debug("received %d EXIT records\n", nr_exit);
 127                err = -1;
 128        }
 129
 130out_free_maps:
 131        cpu_map__put(cpus);
 132        thread_map__put(threads);
 133out_delete_evlist:
 134        perf_evlist__delete(evlist);
 135        return err;
 136}
 137