tools/perf/tests/sw-clock.c

   1 #include <unistd.h>
   2 #include <stdlib.h>
   3 #include <signal.h>
   4 #include <sys/mman.h>
   5
   6 #include "tests.h"
   7 #include "util/evsel.h"
   8 #include "util/evlist.h"
   9 #include "util/cpumap.h"
  10 #include "util/thread_map.h"
  11
  12 #define NR_LOOPS  10000000
  13
  14 /*
  15  * This test will open software clock events (cpu-clock, task-clock)
  16  * then check their frequency -> period conversion has no artifact of
  17  * setting period to 1 forcefully.
  18  */
  19 static int __test__sw_clock_freq(enum perf_sw_ids clock_id)
  20 {
  21         int i, err = -1;
  22         volatile int tmp = 0;
  23         u64 total_periods = 0;
  24         int nr_samples = 0;
  25         union perf_event *event;
  26         struct perf_evsel *evsel;
  27         struct perf_evlist *evlist;
  28         struct perf_event_attr attr = {
  29                 .type = PERF_TYPE_SOFTWARE,
  30                 .config = clock_id,
  31                 .sample_type = PERF_SAMPLE_PERIOD,
  32                 .exclude_kernel = 1,
  33                 .disabled = 1,
  34                 .freq = 1,
  35         };
  36
  37         attr.sample_freq = 500;
  38
  39         evlist = perf_evlist__new();
  40         if (evlist == NULL) {
  41                 pr_debug("perf_evlist__new\n");
  42                 return -1;
  43         }
  44
  45         evsel = perf_evsel__new(&attr);
  46         if (evsel == NULL) {
  47                 pr_debug("perf_evsel__new\n");
  48                 goto out_delete_evlist;
  49         }
  50         perf_evlist__add(evlist, evsel);
  51
  52         evlist->cpus = cpu_map__dummy_new();
  53         evlist->threads = thread_map__new_by_tid(getpid());
  54         if (!evlist->cpus || !evlist->threads) {
  55                 err = -ENOMEM;
  56                 pr_debug("Not enough memory to create thread/cpu maps\n");
  57                 goto out_delete_evlist;
  58         }
  59
  60         if (perf_evlist__open(evlist)) {
  61                 const char *knob = "/proc/sys/kernel/perf_event_max_sample_rate";
  62
  63                 err = -errno;
  64                 pr_debug("Couldn't open evlist: %s\nHint: check %s, using %" PRIu64 " in this test.\n",
  65                          strerror(errno), knob, (u64)attr.sample_freq);
  66                 goto out_delete_evlist;
  67         }
  68
  69         err = perf_evlist__mmap(evlist, 128, true);
  70         if (err < 0) {
  71                 pr_debug("failed to mmap event: %d (%s)\n", errno,
  72                          strerror(errno));
  73                 goto out_delete_evlist;
  74         }
  75
  76         perf_evlist__enable(evlist);
  77
  78         /* collect samples */
  79         for (i = 0; i < NR_LOOPS; i++)
  80                 tmp++;
  81
  82         perf_evlist__disable(evlist);
  83
  84         while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
  85                 struct perf_sample sample;
  86
  87                 if (event->header.type != PERF_RECORD_SAMPLE)
  88                         goto next_event;
  89
  90                 err = perf_evlist__parse_sample(evlist, event, &sample);
  91                 if (err < 0) {
  92                         pr_debug("Error during parse sample\n");
  93                         goto out_delete_evlist;
  94                 }
  95
  96                 total_periods += sample.period;
  97                 nr_samples++;
  98 next_event:
  99                 perf_evlist__mmap_consume(evlist, 0);
 100         }
 101
 102         if ((u64) nr_samples == total_periods) {
 103                 pr_debug("All (%d) samples have period value of 1!\n",
 104                          nr_samples);
 105                 err = -1;
 106         }
 107
 108 out_delete_evlist:
 109         perf_evlist__delete(evlist);
 110         return err;
 111 }
 112
 113 int test__sw_clock_freq(void)
 114 {
 115         int ret;
 116
 117         ret = __test__sw_clock_freq(PERF_COUNT_SW_CPU_CLOCK);
 118         if (!ret)
 119                 ret = __test__sw_clock_freq(PERF_COUNT_SW_TASK_CLOCK);
 120
 121         return ret;
 122 }