// SPDX-License-Identifier: GPL-2.0
/*
 * Benchmark of /proc/kallsyms parsing.
 *
 * Copyright 2020 Google LLC.
 */
#include <stdlib.h>
#include "bench.h"
#include "../util/stat.h"
#include <linux/time64.h>
#include <subcmd/parse-options.h>
#include <symbol/kallsyms.h>

static unsigned int iterations = 100;

static const struct option options[] = {
        OPT_UINTEGER('i', "iterations", &iterations,
                "Number of iterations used to compute average"),
        OPT_END()
};

static const char *const bench_usage[] = {
        "perf bench internals kallsyms-parse <options>",
        NULL
};

static int bench_process_symbol(void *arg __maybe_unused,
                                const char *name __maybe_unused,
                                char type __maybe_unused,
                                u64 start __maybe_unused)
{
        return 0;
}

static int do_kallsyms_parse(void)
{
        struct timeval start, end, diff;
        u64 runtime_us;
        unsigned int i;
        double time_average, time_stddev;
        int err;
        struct stats time_stats;

        init_stats(&time_stats);

        for (i = 0; i < iterations; i++) {
                gettimeofday(&start, NULL);
                err = kallsyms__parse("/proc/kallsyms", NULL,
                                bench_process_symbol);
                if (err)
                        return err;

                gettimeofday(&end, NULL);
                timersub(&end, &start, &diff);
                runtime_us = diff.tv_sec * USEC_PER_SEC + diff.tv_usec;
                update_stats(&time_stats, runtime_us);
        }

        time_average = avg_stats(&time_stats) / USEC_PER_MSEC;
        time_stddev = stddev_stats(&time_stats) / USEC_PER_MSEC;
        printf("  Average kallsyms__parse took: %.3f ms (+- %.3f ms)\n",
                time_average, time_stddev);
        return 0;
}

int bench_kallsyms_parse(int argc, const char **argv)
{
        argc = parse_options(argc, argv, options, bench_usage, 0);
        if (argc) {
                usage_with_options(bench_usage, options);
                exit(EXIT_FAILURE);
        }

        return do_kallsyms_parse();
}