platform_bionic/benchmarks/time_benchmark.cpp
Elliott Hughes e4d5efe231 strftime: format small positive integers ourselves.
A decent chunk of the logcat profile is spent formatting the timestamps
for each line, and most of that time was going to snprintf(3). We should
find all the places that could benefit from a lighter-weight "format an
integer" and share something between them, but this is easy for now.

Before:

-----------------------------------------------------------
Benchmark                 Time             CPU   Iterations
-----------------------------------------------------------
BM_time_strftime        781 ns          775 ns       893102

After:

-----------------------------------------------------------
Benchmark                 Time             CPU   Iterations
-----------------------------------------------------------
BM_time_strftime        149 ns          147 ns      4750782

Much of the remaining time is in tzset() which seems unfortunate.

Test: treehugger
Change-Id: Ie0f7ee462ff1b1abea6f87d4a9a996d768e51056
2021-12-06 14:55:00 -08:00

199 lines
5.6 KiB
C++

/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <sys/syscall.h>
#include <sys/time.h>
#include <time.h>
#include <unistd.h>
#include <benchmark/benchmark.h>
#include "util.h"
static void BM_time_clock_gettime(benchmark::State& state) {
// CLOCK_MONOTONIC is required supported in vdso
timespec t;
while (state.KeepRunning()) {
clock_gettime(CLOCK_MONOTONIC, &t);
}
}
BIONIC_BENCHMARK(BM_time_clock_gettime);
static void BM_time_clock_gettime_syscall(benchmark::State& state) {
// CLOCK_MONOTONIC is required supported in vdso
timespec t;
while (state.KeepRunning()) {
syscall(__NR_clock_gettime, CLOCK_MONOTONIC, &t);
}
}
BIONIC_BENCHMARK(BM_time_clock_gettime_syscall);
static void BM_time_clock_gettime_MONOTONIC_COARSE(benchmark::State& state) {
// CLOCK_MONOTONIC_COARSE is required supported in vdso
timespec t;
while (state.KeepRunning()) {
clock_gettime(CLOCK_MONOTONIC_COARSE, &t);
}
}
BIONIC_BENCHMARK(BM_time_clock_gettime_MONOTONIC_COARSE);
static void BM_time_clock_gettime_MONOTONIC_RAW(benchmark::State& state) {
// CLOCK_MONOTONIC_RAW is required supported in vdso
timespec t;
while (state.KeepRunning()) {
clock_gettime(CLOCK_MONOTONIC_RAW, &t);
}
}
BIONIC_BENCHMARK(BM_time_clock_gettime_MONOTONIC_RAW);
static void BM_time_clock_gettime_REALTIME(benchmark::State& state) {
// CLOCK_REALTIME is required supported in vdso
timespec t;
while (state.KeepRunning()) {
clock_gettime(CLOCK_REALTIME, &t);
}
}
BIONIC_BENCHMARK(BM_time_clock_gettime_REALTIME);
static void BM_time_clock_gettime_REALTIME_COARSE(benchmark::State& state) {
// CLOCK_REALTIME_COARSE is required supported in vdso
timespec t;
while (state.KeepRunning()) {
clock_gettime(CLOCK_REALTIME_COARSE, &t);
}
}
BIONIC_BENCHMARK(BM_time_clock_gettime_REALTIME_COARSE);
static void BM_time_clock_gettime_BOOTTIME(benchmark::State& state) {
// CLOCK_BOOTTIME is optionally supported in vdso
timespec t;
while (state.KeepRunning()) {
clock_gettime(CLOCK_BOOTTIME, &t);
}
}
BIONIC_BENCHMARK(BM_time_clock_gettime_BOOTTIME);
static void BM_time_clock_getres(benchmark::State& state) {
// CLOCK_MONOTONIC is required supported in vdso
timespec t;
while (state.KeepRunning()) {
clock_getres(CLOCK_MONOTONIC, &t);
}
}
BIONIC_BENCHMARK(BM_time_clock_getres);
static void BM_time_clock_getres_syscall(benchmark::State& state) {
// CLOCK_MONOTONIC is required supported in vdso
timespec t;
while (state.KeepRunning()) {
syscall(__NR_clock_getres, CLOCK_MONOTONIC, &t);
}
}
BIONIC_BENCHMARK(BM_time_clock_getres_syscall);
static void BM_time_clock_getres_MONOTONIC_COARSE(benchmark::State& state) {
// CLOCK_MONOTONIC_COARSE is required supported in vdso
timespec t;
while (state.KeepRunning()) {
clock_getres(CLOCK_MONOTONIC_COARSE, &t);
}
}
BIONIC_BENCHMARK(BM_time_clock_getres_MONOTONIC_COARSE);
static void BM_time_clock_getres_MONOTONIC_RAW(benchmark::State& state) {
// CLOCK_MONOTONIC_RAW is required supported in vdso
timespec t;
while (state.KeepRunning()) {
clock_getres(CLOCK_MONOTONIC_RAW, &t);
}
}
BIONIC_BENCHMARK(BM_time_clock_getres_MONOTONIC_RAW);
static void BM_time_clock_getres_REALTIME(benchmark::State& state) {
// CLOCK_REALTIME is required supported in vdso
timespec t;
while (state.KeepRunning()) {
clock_getres(CLOCK_REALTIME, &t);
}
}
BIONIC_BENCHMARK(BM_time_clock_getres_REALTIME);
static void BM_time_clock_getres_REALTIME_COARSE(benchmark::State& state) {
// CLOCK_REALTIME_COARSE is required supported in vdso
timespec t;
while (state.KeepRunning()) {
clock_getres(CLOCK_REALTIME_COARSE, &t);
}
}
BIONIC_BENCHMARK(BM_time_clock_getres_REALTIME_COARSE);
static void BM_time_clock_getres_BOOTTIME(benchmark::State& state) {
// CLOCK_BOOTTIME is optionally supported in vdso
timespec t;
while (state.KeepRunning()) {
clock_getres(CLOCK_BOOTTIME, &t);
}
}
BIONIC_BENCHMARK(BM_time_clock_getres_BOOTTIME);
static void BM_time_gettimeofday(benchmark::State& state) {
timeval tv;
while (state.KeepRunning()) {
gettimeofday(&tv, nullptr);
}
}
BIONIC_BENCHMARK(BM_time_gettimeofday);
void BM_time_gettimeofday_syscall(benchmark::State& state) {
timeval tv;
while (state.KeepRunning()) {
syscall(__NR_gettimeofday, &tv, nullptr);
}
}
BIONIC_BENCHMARK(BM_time_gettimeofday_syscall);
void BM_time_time(benchmark::State& state) {
while (state.KeepRunning()) {
time(nullptr);
}
}
BIONIC_BENCHMARK(BM_time_time);
void BM_time_localtime(benchmark::State& state) {
time_t t = time(nullptr);
while (state.KeepRunning()) {
localtime(&t);
}
}
BIONIC_BENCHMARK(BM_time_localtime);
void BM_time_localtime_r(benchmark::State& state) {
time_t t = time(nullptr);
while (state.KeepRunning()) {
struct tm tm;
localtime_r(&t, &tm);
}
}
BIONIC_BENCHMARK(BM_time_localtime_r);
void BM_time_strftime(benchmark::State& state) {
char buf[128];
time_t t = 0;
struct tm* tm = gmtime(&t);
while (state.KeepRunning()) {
strftime(buf, sizeof(buf), "%Y-%m-%d %H:%M:%S", tm);
}
}
BIONIC_BENCHMARK(BM_time_strftime);