tools/perf/tests/sw-clock.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <errno.h>
   3 #include <inttypes.h>
   4 #include <unistd.h>
   5 #include <stdlib.h>
   6 #include <signal.h>
   7 #include <sys/mman.h>
   8
   9 #include "tests.h"
  10 #include "util/evsel.h"
  11 #include "util/evlist.h"
  12 #include "util/cpumap.h"
  13 #include "util/thread_map.h"
  14 #include <perf/evlist.h>
  15
  16 #define NR_LOOPS  10000000
  17
  18 /*
  19  * This test will open software clock events (cpu-clock, task-clock)
  20  * then check their frequency -> period conversion has no artifact of
  21  * setting period to 1 forcefully.
  22  */
  23 static int __test__sw_clock_freq(enum perf_sw_ids clock_id)
  24 {
  25         int i, err = -1;
  26         volatile int tmp = 0;
  27         u64 total_periods = 0;
  28         int nr_samples = 0;
  29         char sbuf[STRERR_BUFSIZE];
  30         union perf_event *event;
  31         struct evsel *evsel;
  32         struct evlist *evlist;
  33         struct perf_event_attr attr = {
  34                 .type = PERF_TYPE_SOFTWARE,
  35                 .config = clock_id,
  36                 .sample_type = PERF_SAMPLE_PERIOD,
  37                 .exclude_kernel = 1,
  38                 .disabled = 1,
  39                 .freq = 1,
  40         };
  41         struct perf_cpu_map *cpus;
  42         struct perf_thread_map *threads;
  43         struct perf_mmap *md;
  44
  45         attr.sample_freq = 500;
  46
  47         evlist = evlist__new();
  48         if (evlist == NULL) {
  49                 pr_debug("evlist__new\n");
  50                 return -1;
  51         }
  52
  53         evsel = evsel__new(&attr);
  54         if (evsel == NULL) {
  55                 pr_debug("perf_evsel__new\n");
  56                 goto out_delete_evlist;
  57         }
  58         evlist__add(evlist, evsel);
  59
  60         cpus = perf_cpu_map__dummy_new();
  61         threads = thread_map__new_by_tid(getpid());
  62         if (!cpus || !threads) {
  63                 err = -ENOMEM;
  64                 pr_debug("Not enough memory to create thread/cpu maps\n");
  65                 goto out_free_maps;
  66         }
  67
  68         perf_evlist__set_maps(&evlist->core, cpus, threads);
  69
  70         cpus    = NULL;
  71         threads = NULL;
  72
  73         if (evlist__open(evlist)) {
  74                 const char *knob = "/proc/sys/kernel/perf_event_max_sample_rate";
  75
  76                 err = -errno;
  77                 pr_debug("Couldn't open evlist: %s\nHint: check %s, using %" PRIu64 " in this test.\n",
  78                          str_error_r(errno, sbuf, sizeof(sbuf)),
  79                          knob, (u64)attr.sample_freq);
  80                 goto out_delete_evlist;
  81         }
  82
  83         err = perf_evlist__mmap(evlist, 128);
  84         if (err < 0) {
  85                 pr_debug("failed to mmap event: %d (%s)\n", errno,
  86                          str_error_r(errno, sbuf, sizeof(sbuf)));
  87                 goto out_delete_evlist;
  88         }
  89
  90         evlist__enable(evlist);
  91
  92         /* collect samples */
  93         for (i = 0; i < NR_LOOPS; i++)
  94                 tmp++;
  95
  96         evlist__disable(evlist);
  97
  98         md = &evlist->mmap[0];
  99         if (perf_mmap__read_init(md) < 0)
 100                 goto out_init;
 101
 102         while ((event = perf_mmap__read_event(md)) != NULL) {
 103                 struct perf_sample sample;
 104
 105                 if (event->header.type != PERF_RECORD_SAMPLE)
 106                         goto next_event;
 107
 108                 err = perf_evlist__parse_sample(evlist, event, &sample);
 109                 if (err < 0) {
 110                         pr_debug("Error during parse sample\n");
 111                         goto out_delete_evlist;
 112                 }
 113
 114                 total_periods += sample.period;
 115                 nr_samples++;
 116 next_event:
 117                 perf_mmap__consume(md);
 118         }
 119         perf_mmap__read_done(md);
 120
 121 out_init:
 122         if ((u64) nr_samples == total_periods) {
 123                 pr_debug("All (%d) samples have period value of 1!\n",
 124                          nr_samples);
 125                 err = -1;
 126         }
 127
 128 out_free_maps:
 129         perf_cpu_map__put(cpus);
 130         perf_thread_map__put(threads);
 131 out_delete_evlist:
 132         evlist__delete(evlist);
 133         return err;
 134 }
 135
 136 int test__sw_clock_freq(struct test *test __maybe_unused, int subtest __maybe_unused)
 137 {
 138         int ret;
 139
 140         ret = __test__sw_clock_freq(PERF_COUNT_SW_CPU_CLOCK);
 141         if (!ret)
 142                 ret = __test__sw_clock_freq(PERF_COUNT_SW_TASK_CLOCK);
 143
 144         return ret;
 145 }