LXR linux/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
  12static int libperf_print(enum libperf_print_level level,
  13                         const char *fmt, va_list ap)
  14{
  15        return vfprintf(stderr, fmt, ap);
  16}
  17
  18int 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);
  78out_evlist:
  79        perf_evlist__delete(evlist);
  80out_threads:
  81        perf_thread_map__put(threads);
  82        return err;
  83}
  84