tools/lib/perf/Documentation/examples/counting.c

   1 #include <linux/perf_event.h>
   2 #include <perf/evlist.h>
   3 #include <perf/evsel.h>
   4 #include <perf/cpumap.h>
   5 #include <perf/threadmap.h>
   6 #include <perf/mmap.h>
   7 #include <perf/core.h>
   8 #include <perf/event.h>
   9 #include <stdio.h>
  10 #include <unistd.h>
  11
  12 static int libperf_print(enum libperf_print_level level,
  13                          const char *fmt, va_list ap)
  14 {
  15         return vfprintf(stderr, fmt, ap);
  16 }
  17
  18 int main(int argc, char **argv)
  19 {
  20         int count = 100000, err = 0;
  21         struct perf_evlist *evlist;
  22         struct perf_evsel *evsel;
  23         struct perf_thread_map *threads;
  24         struct perf_counts_values counts;
  25
  26         struct perf_event_attr attr1 = {
  27                 .type        = PERF_TYPE_SOFTWARE,
  28                 .config      = PERF_COUNT_SW_CPU_CLOCK,
  29                 .read_format = PERF_FORMAT_TOTAL_TIME_ENABLED|PERF_FORMAT_TOTAL_TIME_RUNNING,
  30                 .disabled    = 1,
  31         };
  32         struct perf_event_attr attr2 = {
  33                 .type        = PERF_TYPE_SOFTWARE,
  34                 .config      = PERF_COUNT_SW_TASK_CLOCK,
  35                 .read_format = PERF_FORMAT_TOTAL_TIME_ENABLED|PERF_FORMAT_TOTAL_TIME_RUNNING,
  36                 .disabled    = 1,
  37         };
  38
  39         libperf_init(libperf_print);
  40         threads = perf_thread_map__new_dummy();
  41         if (!threads) {
  42                 fprintf(stderr, "failed to create threads\n");
  43                 return -1;
  44         }
  45         perf_thread_map__set_pid(threads, 0, 0);
  46         evlist = perf_evlist__new();
  47         if (!evlist) {
  48                 fprintf(stderr, "failed to create evlist\n");
  49                 goto out_threads;
  50         }
  51         evsel = perf_evsel__new(&attr1);
  52         if (!evsel) {
  53                 fprintf(stderr, "failed to create evsel1\n");
  54                 goto out_evlist;
  55         }
  56         perf_evlist__add(evlist, evsel);
  57         evsel = perf_evsel__new(&attr2);
  58         if (!evsel) {
  59                 fprintf(stderr, "failed to create evsel2\n");
  60                 goto out_evlist;
  61         }
  62         perf_evlist__add(evlist, evsel);
  63         perf_evlist__set_maps(evlist, NULL, threads);
  64         err = perf_evlist__open(evlist);
  65         if (err) {
  66                 fprintf(stderr, "failed to open evsel\n");
  67                 goto out_evlist;
  68         }
  69         perf_evlist__enable(evlist);
  70         while (count--);
  71         perf_evlist__disable(evlist);
  72         perf_evlist__for_each_evsel(evlist, evsel) {
  73                 perf_evsel__read(evsel, 0, 0, &counts);
  74                 fprintf(stdout, "count %llu, enabled %llu, run %llu\n",
  75                                 counts.val, counts.ena, counts.run);
  76         }
  77         perf_evlist__close(evlist);
  78 out_evlist:
  79         perf_evlist__delete(evlist);
  80 out_threads:
  81         perf_thread_map__put(threads);
  82         return err;
  83 }