// Copyright 2018 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/mman.h> #include <map> #include "gtest/gtest.h" #include "absl/strings/match.h" #include "absl/strings/numbers.h" #include "absl/strings/str_format.h" #include "absl/strings/str_split.h" #include "test/util/fs_util.h" #include "test/util/posix_error.h" #include "test/util/test_util.h" namespace gvisor { namespace testing { namespace { using ::absl::StrFormat; // AnonUsageFromMeminfo scrapes the current anonymous memory usage from // /proc/meminfo and returns it in bytes. PosixErrorOr<uint64_t> AnonUsageFromMeminfo() { ASSIGN_OR_RETURN_ERRNO(auto meminfo, GetContents("/proc/meminfo")); std::vector<std::string> lines(absl::StrSplit(meminfo, '\n')); // Try to find AnonPages line, the format is AnonPages:\\s+(\\d+) kB\n. for (const auto& line : lines) { if (!absl::StartsWith(line, "AnonPages:")) { continue; } std::vector<std::string> parts( absl::StrSplit(line, ' ', absl::SkipEmpty())); if (parts.size() == 3) { // The size is the second field, let's try to parse it as a number. ASSIGN_OR_RETURN_ERRNO(auto anon_kb, Atoi<uint64_t>(parts[1])); return anon_kb * 1024; } return PosixError(EINVAL, "AnonPages field in /proc/meminfo was malformed"); } return PosixError(EINVAL, "AnonPages field not found in /proc/meminfo"); } TEST(MemoryAccounting, AnonAccountingPreservedOnSaveRestore) { // This test isn't meaningful on Linux. /proc/meminfo reports system-wide // memory usage, which can change arbitrarily in Linux from other activity on // the machine. In gvisor, this test is the only thing running on the // "machine", so values in /proc/meminfo accurately reflect the memory used by // the test. SKIP_IF(!IsRunningOnGvisor()); uint64_t anon_initial = ASSERT_NO_ERRNO_AND_VALUE(AnonUsageFromMeminfo()); // Cause some anonymous memory usage. uint64_t map_bytes = Megabytes(512); char* mem = static_cast<char*>(mmap(nullptr, map_bytes, PROT_READ | PROT_WRITE, MAP_POPULATE | MAP_ANON | MAP_PRIVATE, -1, 0)); ASSERT_NE(mem, MAP_FAILED) << "Map failed, errno: " << errno << " (" << strerror(errno) << ")."; // Write something to each page to prevent them from being decommited on // S/R. Zero pages are dropped on save. for (uint64_t i = 0; i < map_bytes; i += kPageSize) { mem[i] = 'a'; } uint64_t anon_after_alloc = ASSERT_NO_ERRNO_AND_VALUE(AnonUsageFromMeminfo()); EXPECT_THAT(anon_after_alloc, EquivalentWithin(anon_initial + map_bytes, 0.03)); // We have many implicit S/R cycles from scraping /proc/meminfo throughout the // test, but throw an explicit S/R in here as well. MaybeSave(); // Usage should remain the same across S/R. uint64_t anon_after_sr = ASSERT_NO_ERRNO_AND_VALUE(AnonUsageFromMeminfo()); EXPECT_THAT(anon_after_sr, EquivalentWithin(anon_after_alloc, 0.03)); } } // namespace } // namespace testing } // namespace gvisor