platform_system_core/libunwindstack/benchmarks/ElfBenchmark.cpp
David Srbecky a17c2b694c Optimize Memory::ReadString
This function is responsible for majority of CPU time in prefetto.

Reduce the number of memory reads (don't read strings byte-by-byte).

Update all calls of ReadString to include the third parameter to have
a max read.

Add an Elf creation benchmark since this function is on the elf
creation path.

Test: libunwindstack_unit_test
Change-Id: Ia36e1f1a5ba76c9e9f13c43fb9e3691dde7897f2
2020-04-16 15:03:19 -07:00

77 lines
2.2 KiB
C++

/*
* Copyright (C) 2020 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 <err.h>
#include <malloc.h>
#include <stdint.h>
#include <string>
#include <benchmark/benchmark.h>
#include <unwindstack/Elf.h>
#include <unwindstack/Memory.h>
#include "Utils.h"
static void BenchmarkElfCreate(benchmark::State& state, const std::string& elf_file) {
#if defined(__BIONIC__)
uint64_t rss_bytes = 0;
#endif
uint64_t alloc_bytes = 0;
for (auto _ : state) {
state.PauseTiming();
#if defined(__BIONIC__)
mallopt(M_PURGE, 0);
uint64_t rss_bytes_before = 0;
GatherRss(&rss_bytes_before);
#endif
uint64_t alloc_bytes_before = mallinfo().uordblks;
auto file_memory = unwindstack::Memory::CreateFileMemory(elf_file, 0);
state.ResumeTiming();
unwindstack::Elf elf(file_memory.release());
if (!elf.Init() || !elf.valid()) {
errx(1, "Internal Error: Cannot open elf.");
}
state.PauseTiming();
#if defined(__BIONIC__)
mallopt(M_PURGE, 0);
#endif
alloc_bytes += mallinfo().uordblks - alloc_bytes_before;
#if defined(__BIONIC__)
GatherRss(&rss_bytes);
rss_bytes -= rss_bytes_before;
#endif
state.ResumeTiming();
}
#if defined(__BIONIC__)
state.counters["RSS_BYTES"] = rss_bytes / static_cast<double>(state.iterations());
#endif
state.counters["ALLOCATED_BYTES"] = alloc_bytes / static_cast<double>(state.iterations());
}
void BM_elf_create(benchmark::State& state) {
BenchmarkElfCreate(state, GetElfFile());
}
BENCHMARK(BM_elf_create);
void BM_elf_create_compressed(benchmark::State& state) {
BenchmarkElfCreate(state, GetCompressedElfFile());
}
BENCHMARK(BM_elf_create_compressed);