LXR linux/tools/perf/bench/kallsyms-parse.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Benchmark of /proc/kallsyms parsing.
   4 *
   5 * Copyright 2020 Google LLC.
   6 */
   7#include <stdlib.h>
   8#include "bench.h"
   9#include "../util/stat.h"
  10#include <linux/time64.h>
  11#include <subcmd/parse-options.h>
  12#include <symbol/kallsyms.h>
  13
  14static unsigned int iterations = 100;
  15
  16static const struct option options[] = {
  17        OPT_UINTEGER('i', "iterations", &iterations,
  18                "Number of iterations used to compute average"),
  19        OPT_END()
  20};
  21
  22static const char *const bench_usage[] = {
  23        "perf bench internals kallsyms-parse <options>",
  24        NULL
  25};
  26
  27static int bench_process_symbol(void *arg __maybe_unused,
  28                                const char *name __maybe_unused,
  29                                char type __maybe_unused,
  30                                u64 start __maybe_unused)
  31{
  32        return 0;
  33}
  34
  35static int do_kallsyms_parse(void)
  36{
  37        struct timeval start, end, diff;
  38        u64 runtime_us;
  39        unsigned int i;
  40        double time_average, time_stddev;
  41        int err;
  42        struct stats time_stats;
  43
  44        init_stats(&time_stats);
  45
  46        for (i = 0; i < iterations; i++) {
  47                gettimeofday(&start, NULL);
  48                err = kallsyms__parse("/proc/kallsyms", NULL,
  49                                bench_process_symbol);
  50                if (err)
  51                        return err;
  52
  53                gettimeofday(&end, NULL);
  54                timersub(&end, &start, &diff);
  55                runtime_us = diff.tv_sec * USEC_PER_SEC + diff.tv_usec;
  56                update_stats(&time_stats, runtime_us);
  57        }
  58
  59        time_average = avg_stats(&time_stats) / USEC_PER_MSEC;
  60        time_stddev = stddev_stats(&time_stats) / USEC_PER_MSEC;
  61        printf("  Average kallsyms__parse took: %.3f ms (+- %.3f ms)\n",
  62                time_average, time_stddev);
  63        return 0;
  64}
  65
  66int bench_kallsyms_parse(int argc, const char **argv)
  67{
  68        argc = parse_options(argc, argv, options, bench_usage, 0);
  69        if (argc) {
  70                usage_with_options(bench_usage, options);
  71                exit(EXIT_FAILURE);
  72        }
  73
  74        return do_kallsyms_parse();
  75}
  76