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Diffstat (limited to 'test/perf/linux/getdents_benchmark.cc')
-rw-r--r-- | test/perf/linux/getdents_benchmark.cc | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/test/perf/linux/getdents_benchmark.cc b/test/perf/linux/getdents_benchmark.cc new file mode 100644 index 000000000..d8e81fa8c --- /dev/null +++ b/test/perf/linux/getdents_benchmark.cc @@ -0,0 +1,149 @@ +// Copyright 2020 The gVisor Authors. +// +// 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/stat.h> +#include <sys/types.h> +#include <unistd.h> + +#include "gtest/gtest.h" +#include "benchmark/benchmark.h" +#include "test/util/file_descriptor.h" +#include "test/util/fs_util.h" +#include "test/util/temp_path.h" +#include "test/util/test_util.h" + +#ifndef SYS_getdents64 +#if defined(__x86_64__) +#define SYS_getdents64 217 +#elif defined(__aarch64__) +#define SYS_getdents64 217 +#else +#error "Unknown architecture" +#endif +#endif // SYS_getdents64 + +namespace gvisor { +namespace testing { + +namespace { + +constexpr int kBufferSize = 65536; + +PosixErrorOr<TempPath> CreateDirectory(int count, + std::vector<std::string>* files) { + ASSIGN_OR_RETURN_ERRNO(TempPath dir, TempPath::CreateDir()); + + ASSIGN_OR_RETURN_ERRNO(FileDescriptor dfd, + Open(dir.path(), O_RDONLY | O_DIRECTORY)); + + for (int i = 0; i < count; i++) { + auto file = NewTempRelPath(); + auto res = MknodAt(dfd, file, S_IFREG | 0644, 0); + RETURN_IF_ERRNO(res); + files->push_back(file); + } + + return std::move(dir); +} + +PosixError CleanupDirectory(const TempPath& dir, + std::vector<std::string>* files) { + ASSIGN_OR_RETURN_ERRNO(FileDescriptor dfd, + Open(dir.path(), O_RDONLY | O_DIRECTORY)); + + for (auto it = files->begin(); it != files->end(); ++it) { + auto res = UnlinkAt(dfd, *it, 0); + RETURN_IF_ERRNO(res); + } + return NoError(); +} + +// Creates a directory containing `files` files, and reads all the directory +// entries from the directory using a single FD. +void BM_GetdentsSameFD(benchmark::State& state) { + // Create directory with given files. + const int count = state.range(0); + + // Keep a vector of all of the file TempPaths that is destroyed before dir. + // + // Normally, we'd simply allow dir to recursively clean up the contained + // files, but that recursive cleanup uses getdents, which may be very slow in + // extreme benchmarks. + TempPath dir; + std::vector<std::string> files; + dir = ASSERT_NO_ERRNO_AND_VALUE(CreateDirectory(count, &files)); + + FileDescriptor fd = + ASSERT_NO_ERRNO_AND_VALUE(Open(dir.path(), O_RDONLY | O_DIRECTORY)); + char buffer[kBufferSize]; + + // We read all directory entries on each iteration, but report this as a + // "batch" iteration so that reported times are per file. + while (state.KeepRunningBatch(count)) { + ASSERT_THAT(lseek(fd.get(), 0, SEEK_SET), SyscallSucceeds()); + + int ret; + do { + ASSERT_THAT(ret = syscall(SYS_getdents64, fd.get(), buffer, kBufferSize), + SyscallSucceeds()); + } while (ret > 0); + } + + ASSERT_NO_ERRNO(CleanupDirectory(dir, &files)); + + state.SetItemsProcessed(state.iterations()); +} + +BENCHMARK(BM_GetdentsSameFD)->Range(1, 1 << 16)->UseRealTime(); + +// Creates a directory containing `files` files, and reads all the directory +// entries from the directory using a new FD each time. +void BM_GetdentsNewFD(benchmark::State& state) { + // Create directory with given files. + const int count = state.range(0); + + // Keep a vector of all of the file TempPaths that is destroyed before dir. + // + // Normally, we'd simply allow dir to recursively clean up the contained + // files, but that recursive cleanup uses getdents, which may be very slow in + // extreme benchmarks. + TempPath dir; + std::vector<std::string> files; + dir = ASSERT_NO_ERRNO_AND_VALUE(CreateDirectory(count, &files)); + char buffer[kBufferSize]; + + // We read all directory entries on each iteration, but report this as a + // "batch" iteration so that reported times are per file. + while (state.KeepRunningBatch(count)) { + FileDescriptor fd = + ASSERT_NO_ERRNO_AND_VALUE(Open(dir.path(), O_RDONLY | O_DIRECTORY)); + + int ret; + do { + ASSERT_THAT(ret = syscall(SYS_getdents64, fd.get(), buffer, kBufferSize), + SyscallSucceeds()); + } while (ret > 0); + } + + ASSERT_NO_ERRNO(CleanupDirectory(dir, &files)); + + state.SetItemsProcessed(state.iterations()); +} + +BENCHMARK(BM_GetdentsNewFD)->Range(1, 1 << 12)->UseRealTime(); + +} // namespace + +} // namespace testing +} // namespace gvisor |