5d9a7ba0dc
System calls can be pretty slow. This is mako, which has one of our
lowest latencies:
iterations ns/op
BM_unistd_getpid 10000000 209
BM_unistd_gettid 200000000 8
Bug: 15297299 (kernel panic from too many gettid calls)
Bug: 15315766 (excessive gettid overhead in liblogd)
Change-Id: I49656c0fc5b5d092390264a59e4f2c0d8a8b1aeb
42 lines
1.0 KiB
C++
42 lines
1.0 KiB
C++
/*
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* Copyright (C) 2014 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "benchmark.h"
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#include <unistd.h>
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static void BM_unistd_getpid(int iters) {
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StartBenchmarkTiming();
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for (int i = 0; i < iters; ++i) {
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getpid();
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}
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StopBenchmarkTiming();
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}
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BENCHMARK(BM_unistd_getpid);
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static void BM_unistd_gettid(int iters) {
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StartBenchmarkTiming();
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for (int i = 0; i < iters; ++i) {
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gettid();
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}
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StopBenchmarkTiming();
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}
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BENCHMARK(BM_unistd_gettid);
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