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 | |
14 | static unsigned int iterations = 100; |
15 | |
16 | static const struct option options[] = { |
17 | OPT_UINTEGER('i', "iterations" , &iterations, |
18 | "Number of iterations used to compute average" ), |
19 | OPT_END() |
20 | }; |
21 | |
22 | static const char *const bench_usage[] = { |
23 | "perf bench internals kallsyms-parse <options>" , |
24 | NULL |
25 | }; |
26 | |
27 | static 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 | |
35 | static 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(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(stats: &time_stats, val: runtime_us); |
57 | } |
58 | |
59 | time_average = avg_stats(stats: &time_stats) / USEC_PER_MSEC; |
60 | time_stddev = stddev_stats(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 | |
66 | int 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 | |