diff options
author | Ian Lewis <ianmlewis@gmail.com> | 2020-08-17 21:44:31 -0400 |
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committer | Ian Lewis <ianmlewis@gmail.com> | 2020-08-17 21:44:31 -0400 |
commit | ac324f646ee3cb7955b0b45a7453aeb9671cbdf1 (patch) | |
tree | 0cbc5018e8807421d701d190dc20525726c7ca76 /test/perf/linux/mapping_benchmark.cc | |
parent | 352ae1022ce19de28fc72e034cc469872ad79d06 (diff) | |
parent | 6d0c5803d557d453f15ac6f683697eeb46dab680 (diff) |
Merge branch 'master' into ip-forwarding
- Merges aleksej-paschenko's with HEAD
- Adds vfs2 support for ip_forward
Diffstat (limited to 'test/perf/linux/mapping_benchmark.cc')
-rw-r--r-- | test/perf/linux/mapping_benchmark.cc | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/test/perf/linux/mapping_benchmark.cc b/test/perf/linux/mapping_benchmark.cc new file mode 100644 index 000000000..39c30fe69 --- /dev/null +++ b/test/perf/linux/mapping_benchmark.cc @@ -0,0 +1,163 @@ +// 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 <stdlib.h> +#include <sys/mman.h> +#include <unistd.h> + +#include "gtest/gtest.h" +#include "benchmark/benchmark.h" +#include "test/util/logging.h" +#include "test/util/memory_util.h" +#include "test/util/posix_error.h" +#include "test/util/test_util.h" + +namespace gvisor { +namespace testing { + +namespace { + +// Conservative value for /proc/sys/vm/max_map_count, which limits the number of +// VMAs, minus a safety margin for VMAs that already exist for the test binary. +// The default value for max_map_count is +// include/linux/mm.h:DEFAULT_MAX_MAP_COUNT = 65530. +constexpr size_t kMaxVMAs = 64001; + +// Map then unmap pages without touching them. +void BM_MapUnmap(benchmark::State& state) { + // Number of pages to map. + const int pages = state.range(0); + + while (state.KeepRunning()) { + void* addr = mmap(0, pages * kPageSize, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + TEST_CHECK_MSG(addr != MAP_FAILED, "mmap failed"); + + int ret = munmap(addr, pages * kPageSize); + TEST_CHECK_MSG(ret == 0, "munmap failed"); + } +} + +BENCHMARK(BM_MapUnmap)->Range(1, 1 << 17)->UseRealTime(); + +// Map, touch, then unmap pages. +void BM_MapTouchUnmap(benchmark::State& state) { + // Number of pages to map. + const int pages = state.range(0); + + while (state.KeepRunning()) { + void* addr = mmap(0, pages * kPageSize, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + TEST_CHECK_MSG(addr != MAP_FAILED, "mmap failed"); + + char* c = reinterpret_cast<char*>(addr); + char* end = c + pages * kPageSize; + while (c < end) { + *c = 42; + c += kPageSize; + } + + int ret = munmap(addr, pages * kPageSize); + TEST_CHECK_MSG(ret == 0, "munmap failed"); + } +} + +BENCHMARK(BM_MapTouchUnmap)->Range(1, 1 << 17)->UseRealTime(); + +// Map and touch many pages, unmapping all at once. +// +// NOTE(b/111429208): This is a regression test to ensure performant mapping and +// allocation even with tons of mappings. +void BM_MapTouchMany(benchmark::State& state) { + // Number of pages to map. + const int page_count = state.range(0); + + while (state.KeepRunning()) { + std::vector<void*> pages; + + for (int i = 0; i < page_count; i++) { + void* addr = mmap(nullptr, kPageSize, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + TEST_CHECK_MSG(addr != MAP_FAILED, "mmap failed"); + + char* c = reinterpret_cast<char*>(addr); + *c = 42; + + pages.push_back(addr); + } + + for (void* addr : pages) { + int ret = munmap(addr, kPageSize); + TEST_CHECK_MSG(ret == 0, "munmap failed"); + } + } + + state.SetBytesProcessed(kPageSize * page_count * state.iterations()); +} + +BENCHMARK(BM_MapTouchMany)->Range(1, 1 << 12)->UseRealTime(); + +void BM_PageFault(benchmark::State& state) { + // Map the region in which we will take page faults. To ensure that each page + // fault maps only a single page, each page we touch must correspond to a + // distinct VMA. Thus we need a 1-page gap between each 1-page VMA. However, + // each gap consists of a PROT_NONE VMA, instead of an unmapped hole, so that + // if there are background threads running, they can't inadvertently creating + // mappings in our gaps that are unmapped when the test ends. + size_t test_pages = kMaxVMAs; + // Ensure that test_pages is odd, since we want the test region to both + // begin and end with a mapped page. + if (test_pages % 2 == 0) { + test_pages--; + } + const size_t test_region_bytes = test_pages * kPageSize; + // Use MAP_SHARED here because madvise(MADV_DONTNEED) on private mappings on + // gVisor won't force future sentry page faults (by design). Use MAP_POPULATE + // so that Linux pre-allocates the shmem file used to back the mapping. + Mapping m = ASSERT_NO_ERRNO_AND_VALUE( + MmapAnon(test_region_bytes, PROT_READ, MAP_SHARED | MAP_POPULATE)); + for (size_t i = 0; i < test_pages / 2; i++) { + ASSERT_THAT( + mprotect(reinterpret_cast<void*>(m.addr() + ((2 * i + 1) * kPageSize)), + kPageSize, PROT_NONE), + SyscallSucceeds()); + } + + const size_t mapped_pages = test_pages / 2 + 1; + // "Start" at the end of the mapped region to force the mapped region to be + // reset, since we mapped it with MAP_POPULATE. + size_t cur_page = mapped_pages; + for (auto _ : state) { + if (cur_page >= mapped_pages) { + // We've reached the end of our mapped region and have to reset it to + // incur page faults again. + state.PauseTiming(); + ASSERT_THAT(madvise(m.ptr(), test_region_bytes, MADV_DONTNEED), + SyscallSucceeds()); + cur_page = 0; + state.ResumeTiming(); + } + const uintptr_t addr = m.addr() + (2 * cur_page * kPageSize); + const char c = *reinterpret_cast<volatile char*>(addr); + benchmark::DoNotOptimize(c); + cur_page++; + } +} + +BENCHMARK(BM_PageFault)->UseRealTime(); + +} // namespace + +} // namespace testing +} // namespace gvisor |