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// 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
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