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1// SPDX-License-Identifier: GPL-2.02/*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 NULL25};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