LXR linux/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#include <linux/string.h>
   9
  10#include "tests.h"
  11#include "util/debug.h"
  12#include "util/evsel.h"
  13#include "util/evlist.h"
  14#include "util/cpumap.h"
  15#include "util/mmap.h"
  16#include "util/thread_map.h"
  17#include <perf/evlist.h>
  18#include <perf/mmap.h>
  19
  20#define NR_LOOPS  10000000
  21
  22/*
  23 * This test will open software clock events (cpu-clock, task-clock)
  24 * then check their frequency -> period conversion has no artifact of
  25 * setting period to 1 forcefully.
  26 */
  27static int __test__sw_clock_freq(enum perf_sw_ids clock_id)
  28{
  29        int i, err = -1;
  30        volatile int tmp = 0;
  31        u64 total_periods = 0;
  32        int nr_samples = 0;
  33        char sbuf[STRERR_BUFSIZE];
  34        union perf_event *event;
  35        struct evsel *evsel;
  36        struct evlist *evlist;
  37        struct perf_event_attr attr = {
  38                .type = PERF_TYPE_SOFTWARE,
  39                .config = clock_id,
  40                .sample_type = PERF_SAMPLE_PERIOD,
  41                .exclude_kernel = 1,
  42                .disabled = 1,
  43                .freq = 1,
  44        };
  45        struct perf_cpu_map *cpus;
  46        struct perf_thread_map *threads;
  47        struct mmap *md;
  48
  49        attr.sample_freq = 500;
  50
  51        evlist = evlist__new();
  52        if (evlist == NULL) {
  53                pr_debug("evlist__new\n");
  54                return -1;
  55        }
  56
  57        evsel = evsel__new(&attr);
  58        if (evsel == NULL) {
  59                pr_debug("perf_evsel__new\n");
  60                goto out_delete_evlist;
  61        }
  62        evlist__add(evlist, evsel);
  63
  64        cpus = perf_cpu_map__dummy_new();
  65        threads = thread_map__new_by_tid(getpid());
  66        if (!cpus || !threads) {
  67                err = -ENOMEM;
  68                pr_debug("Not enough memory to create thread/cpu maps\n");
  69                goto out_free_maps;
  70        }
  71
  72        perf_evlist__set_maps(&evlist->core, cpus, threads);
  73
  74        cpus    = NULL;
  75        threads = NULL;
  76
  77        if (evlist__open(evlist)) {
  78                const char *knob = "/proc/sys/kernel/perf_event_max_sample_rate";
  79
  80                err = -errno;
  81                pr_debug("Couldn't open evlist: %s\nHint: check %s, using %" PRIu64 " in this test.\n",
  82                         str_error_r(errno, sbuf, sizeof(sbuf)),
  83                         knob, (u64)attr.sample_freq);
  84                goto out_delete_evlist;
  85        }
  86
  87        err = evlist__mmap(evlist, 128);
  88        if (err < 0) {
  89                pr_debug("failed to mmap event: %d (%s)\n", errno,
  90                         str_error_r(errno, sbuf, sizeof(sbuf)));
  91                goto out_delete_evlist;
  92        }
  93
  94        evlist__enable(evlist);
  95
  96        /* collect samples */
  97        for (i = 0; i < NR_LOOPS; i++)
  98                tmp++;
  99
 100        evlist__disable(evlist);
 101
 102        md = &evlist->mmap[0];
 103        if (perf_mmap__read_init(&md->core) < 0)
 104                goto out_init;
 105
 106        while ((event = perf_mmap__read_event(&md->core)) != NULL) {
 107                struct perf_sample sample;
 108
 109                if (event->header.type != PERF_RECORD_SAMPLE)
 110                        goto next_event;
 111
 112                err = perf_evlist__parse_sample(evlist, event, &sample);
 113                if (err < 0) {
 114                        pr_debug("Error during parse sample\n");
 115                        goto out_delete_evlist;
 116                }
 117
 118                total_periods += sample.period;
 119                nr_samples++;
 120next_event:
 121                perf_mmap__consume(&md->core);
 122        }
 123        perf_mmap__read_done(&md->core);
 124
 125out_init:
 126        if ((u64) nr_samples == total_periods) {
 127                pr_debug("All (%d) samples have period value of 1!\n",
 128                         nr_samples);
 129                err = -1;
 130        }
 131
 132out_free_maps:
 133        perf_cpu_map__put(cpus);
 134        perf_thread_map__put(threads);
 135out_delete_evlist:
 136        evlist__delete(evlist);
 137        return err;
 138}
 139
 140int test__sw_clock_freq(struct test *test __maybe_unused, int subtest __maybe_unused)
 141{
 142        int ret;
 143
 144        ret = __test__sw_clock_freq(PERF_COUNT_SW_CPU_CLOCK);
 145        if (!ret)
 146                ret = __test__sw_clock_freq(PERF_COUNT_SW_TASK_CLOCK);
 147
 148        return ret;
 149}
 150