LXR linux/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 */
  19static 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        char sbuf[STRERR_BUFSIZE];
  26        union perf_event *event;
  27        struct perf_evsel *evsel;
  28        struct perf_evlist *evlist;
  29        struct perf_event_attr attr = {
  30                .type = PERF_TYPE_SOFTWARE,
  31                .config = clock_id,
  32                .sample_type = PERF_SAMPLE_PERIOD,
  33                .exclude_kernel = 1,
  34                .disabled = 1,
  35                .freq = 1,
  36        };
  37        struct cpu_map *cpus;
  38        struct thread_map *threads;
  39
  40        attr.sample_freq = 500;
  41
  42        evlist = perf_evlist__new();
  43        if (evlist == NULL) {
  44                pr_debug("perf_evlist__new\n");
  45                return -1;
  46        }
  47
  48        evsel = perf_evsel__new(&attr);
  49        if (evsel == NULL) {
  50                pr_debug("perf_evsel__new\n");
  51                goto out_delete_evlist;
  52        }
  53        perf_evlist__add(evlist, evsel);
  54
  55        cpus = cpu_map__dummy_new();
  56        threads = thread_map__new_by_tid(getpid());
  57        if (!cpus || !threads) {
  58                err = -ENOMEM;
  59                pr_debug("Not enough memory to create thread/cpu maps\n");
  60                goto out_free_maps;
  61        }
  62
  63        perf_evlist__set_maps(evlist, cpus, threads);
  64
  65        cpus    = NULL;
  66        threads = NULL;
  67
  68        if (perf_evlist__open(evlist)) {
  69                const char *knob = "/proc/sys/kernel/perf_event_max_sample_rate";
  70
  71                err = -errno;
  72                pr_debug("Couldn't open evlist: %s\nHint: check %s, using %" PRIu64 " in this test.\n",
  73                         strerror_r(errno, sbuf, sizeof(sbuf)),
  74                         knob, (u64)attr.sample_freq);
  75                goto out_delete_evlist;
  76        }
  77
  78        err = perf_evlist__mmap(evlist, 128, true);
  79        if (err < 0) {
  80                pr_debug("failed to mmap event: %d (%s)\n", errno,
  81                         strerror_r(errno, sbuf, sizeof(sbuf)));
  82                goto out_delete_evlist;
  83        }
  84
  85        perf_evlist__enable(evlist);
  86
  87        /* collect samples */
  88        for (i = 0; i < NR_LOOPS; i++)
  89                tmp++;
  90
  91        perf_evlist__disable(evlist);
  92
  93        while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
  94                struct perf_sample sample;
  95
  96                if (event->header.type != PERF_RECORD_SAMPLE)
  97                        goto next_event;
  98
  99                err = perf_evlist__parse_sample(evlist, event, &sample);
 100                if (err < 0) {
 101                        pr_debug("Error during parse sample\n");
 102                        goto out_delete_evlist;
 103                }
 104
 105                total_periods += sample.period;
 106                nr_samples++;
 107next_event:
 108                perf_evlist__mmap_consume(evlist, 0);
 109        }
 110
 111        if ((u64) nr_samples == total_periods) {
 112                pr_debug("All (%d) samples have period value of 1!\n",
 113                         nr_samples);
 114                err = -1;
 115        }
 116
 117out_free_maps:
 118        cpu_map__put(cpus);
 119        thread_map__put(threads);
 120out_delete_evlist:
 121        perf_evlist__delete(evlist);
 122        return err;
 123}
 124
 125int test__sw_clock_freq(void)
 126{
 127        int ret;
 128
 129        ret = __test__sw_clock_freq(PERF_COUNT_SW_CPU_CLOCK);
 130        if (!ret)
 131                ret = __test__sw_clock_freq(PERF_COUNT_SW_TASK_CLOCK);
 132
 133        return ret;
 134}
 135