// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/*
 * uprobe.c
 *
 * uprobe benchmarks
 *
 *  Copyright (C) 2023, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
 */
#include "../perf.h"
#include "../util/util.h"
#include <subcmd/parse-options.h>
#include "../builtin.h"
#include "bench.h"
#include <linux/compiler.h>
#include <linux/time64.h>

#include <inttypes.h>
#include <stdio.h>
#include <sys/time.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
#include <stdlib.h>

#define LOOPS_DEFAULT 1000
static int loops = LOOPS_DEFAULT;

enum bench_uprobe {
        BENCH_UPROBE__BASELINE,
        BENCH_UPROBE__EMPTY,
        BENCH_UPROBE__TRACE_PRINTK,
        BENCH_UPROBE__EMPTY_RET,
        BENCH_UPROBE__TRACE_PRINTK_RET,
};

static const struct option options[] = {
        OPT_INTEGER('l', "loop",        &loops,         "Specify number of loops"),
        OPT_END()
};

static const char * const bench_uprobe_usage[] = {
        "perf bench uprobe <options>",
        NULL
};

#ifdef HAVE_BPF_SKEL
#include "bpf_skel/bench_uprobe.skel.h"

#define bench_uprobe__attach_uprobe(prog) \
        skel->links.prog = bpf_program__attach_uprobe_opts(/*prog=*/skel->progs.prog, \
                                                           /*pid=*/-1, \
                                                           /*binary_path=*/"libc.so.6", \
                                                           /*func_offset=*/0, \
                                                           /*opts=*/&uprobe_opts); \
        if (!skel->links.prog) { \
                err = -errno; \
                fprintf(stderr, "Failed to attach bench uprobe \"%s\": %m\n", #prog); \
                goto cleanup; \
        }

struct bench_uprobe_bpf *skel;

static int bench_uprobe__setup_bpf_skel(enum bench_uprobe bench)
{
        DECLARE_LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);
        int err;

        /* Load and verify BPF application */
        skel = bench_uprobe_bpf__open();
        if (!skel) {
                fprintf(stderr, "Failed to open and load uprobes bench BPF skeleton\n");
                return -1;
        }

        err = bench_uprobe_bpf__load(skel);
        if (err) {
                fprintf(stderr, "Failed to load and verify BPF skeleton\n");
                goto cleanup;
        }

        uprobe_opts.func_name = "usleep";
        switch (bench) {
        case BENCH_UPROBE__BASELINE:                                                    break;
        case BENCH_UPROBE__EMPTY:        bench_uprobe__attach_uprobe(empty);            break;
        case BENCH_UPROBE__TRACE_PRINTK: bench_uprobe__attach_uprobe(trace_printk);     break;
        case BENCH_UPROBE__EMPTY_RET:    bench_uprobe__attach_uprobe(empty_ret);        break;
        case BENCH_UPROBE__TRACE_PRINTK_RET: bench_uprobe__attach_uprobe(trace_printk_ret); break;
        default:
                fprintf(stderr, "Invalid bench: %d\n", bench);
                goto cleanup;
        }

        return err;
cleanup:
        bench_uprobe_bpf__destroy(skel);
        skel = NULL;
        return err;
}

static void bench_uprobe__teardown_bpf_skel(void)
{
        if (skel) {
                bench_uprobe_bpf__destroy(skel);
                skel = NULL;
        }
}
#else
static int bench_uprobe__setup_bpf_skel(enum bench_uprobe bench __maybe_unused) { return 0; }
static void bench_uprobe__teardown_bpf_skel(void) {};
#endif

static int bench_uprobe_format__default_fprintf(const char *name, const char *unit, u64 diff, FILE *fp)
{
        static u64 baseline, previous;
        s64 diff_to_baseline = diff - baseline,
            diff_to_previous = diff - previous;
        int printed = fprintf(fp, "# Executed %'d %s calls\n", loops, name);

        printed += fprintf(fp, " %14s: %'" PRIu64 " %ss", "Total time", diff, unit);

        if (baseline) {
                printed += fprintf(fp, " %s%'" PRId64 " to baseline", diff_to_baseline > 0 ? "+" : "", diff_to_baseline);

                if (previous != baseline)
                        fprintf(stdout, " %s%'" PRId64 " to previous", diff_to_previous > 0 ? "+" : "", diff_to_previous);
        }

        printed += fprintf(fp, "\n\n %'.3f %ss/op", (double)diff / (double)loops, unit);

        if (baseline) {
                printed += fprintf(fp, " %'.3f %ss/op to baseline", (double)diff_to_baseline / (double)loops, unit);

                if (previous != baseline)
                        printed += fprintf(fp, " %'.3f %ss/op to previous", (double)diff_to_previous / (double)loops, unit);
        } else {
                baseline = diff;
        }

        fputc('\n', fp);

        previous = diff;

        return printed + 1;
}

static int bench_uprobe(int argc, const char **argv, enum bench_uprobe bench)
{
        const char *name = "usleep(1000)", *unit = "usec";
        struct timespec start, end;
        u64 diff;
        int i;

        argc = parse_options(argc, argv, options, bench_uprobe_usage, 0);

        if (bench != BENCH_UPROBE__BASELINE && bench_uprobe__setup_bpf_skel(bench) < 0)
                return 0;

        clock_gettime(CLOCK_REALTIME, &start);

        for (i = 0; i < loops; i++) {
                usleep(USEC_PER_MSEC);
        }

        clock_gettime(CLOCK_REALTIME, &end);

        diff = end.tv_sec * NSEC_PER_SEC + end.tv_nsec - (start.tv_sec * NSEC_PER_SEC + start.tv_nsec);
        diff /= NSEC_PER_USEC;

        switch (bench_format) {
        case BENCH_FORMAT_DEFAULT:
                bench_uprobe_format__default_fprintf(name, unit, diff, stdout);
                break;

        case BENCH_FORMAT_SIMPLE:
                printf("%" PRIu64 "\n", diff);
                break;

        default:
                /* reaching here is something of a disaster */
                fprintf(stderr, "Unknown format:%d\n", bench_format);
                exit(1);
        }

        if (bench != BENCH_UPROBE__BASELINE)
                bench_uprobe__teardown_bpf_skel();

        return 0;
}

int bench_uprobe_baseline(int argc, const char **argv)
{
        return bench_uprobe(argc, argv, BENCH_UPROBE__BASELINE);
}

int bench_uprobe_empty(int argc, const char **argv)
{
        return bench_uprobe(argc, argv, BENCH_UPROBE__EMPTY);
}

int bench_uprobe_trace_printk(int argc, const char **argv)
{
        return bench_uprobe(argc, argv, BENCH_UPROBE__TRACE_PRINTK);
}

int bench_uprobe_empty_ret(int argc, const char **argv)
{
        return bench_uprobe(argc, argv, BENCH_UPROBE__EMPTY_RET);
}

int bench_uprobe_trace_printk_ret(int argc, const char **argv)
{
        return bench_uprobe(argc, argv, BENCH_UPROBE__TRACE_PRINTK_RET);
}