startop: Add iorap.stress.memory tool to test system with less RAM
iorap.stress.memory <optional:bytecount> will mlock that amount of RAM
with randomly-written values, ensuring we avoid kernel optimizations
such as swap, zram, ksm, etc.
Bug: 137397549
Test: iorap.stress.memory # and visually inspect VmLck output.
Change-Id: Icf0786b2607a9a8bc7b6d77aa119abfc0249e7e0
diff --git a/startop/iorap/stress/Android.bp b/startop/iorap/stress/Android.bp
new file mode 100644
index 0000000..f9f251bd
--- /dev/null
+++ b/startop/iorap/stress/Android.bp
@@ -0,0 +1,33 @@
+//
+// 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.
+//
+
+cc_binary {
+ name: "iorap.stress.memory",
+ srcs: ["main_memory.cc"],
+
+ cflags: [
+ "-Wall",
+ "-Wextra",
+ "-Werror",
+ "-Wno-unused-parameter"
+ ],
+
+ shared_libs: [
+ "libbase"
+ ],
+
+ host_supported: true,
+}
diff --git a/startop/iorap/stress/main_memory.cc b/startop/iorap/stress/main_memory.cc
new file mode 100644
index 0000000..1f26861
--- /dev/null
+++ b/startop/iorap/stress/main_memory.cc
@@ -0,0 +1,126 @@
+//
+// 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 <chrono>
+#include <fstream>
+#include <iostream>
+#include <random>
+#include <string>
+
+#include <string.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+
+#include <android-base/parseint.h>
+
+static constexpr size_t kBytesPerMb = 1048576;
+const size_t kMemoryAllocationSize = 2 * 1024 * kBytesPerMb;
+
+#define USE_MLOCKALL 0
+
+std::string GetProcessStatus(const char* key) {
+ // Build search pattern of key and separator.
+ std::string pattern(key);
+ pattern.push_back(':');
+
+ // Search for status lines starting with pattern.
+ std::ifstream fs("/proc/self/status");
+ std::string line;
+ while (std::getline(fs, line)) {
+ if (strncmp(pattern.c_str(), line.c_str(), pattern.size()) == 0) {
+ // Skip whitespace in matching line (if any).
+ size_t pos = line.find_first_not_of(" \t", pattern.size());
+ if (pos == std::string::npos) {
+ break;
+ }
+ return std::string(line, pos);
+ }
+ }
+ return "<unknown>";
+}
+
+int main(int argc, char** argv) {
+ size_t allocationSize = 0;
+ if (argc >= 2) {
+ if (!android::base::ParseUint(argv[1], /*out*/&allocationSize)) {
+ std::cerr << "Failed to parse the allocation size (must be 0,MAX_SIZE_T)" << std::endl;
+ return 1;
+ }
+ } else {
+ allocationSize = kMemoryAllocationSize;
+ }
+
+ void* mem = malloc(allocationSize);
+ if (mem == nullptr) {
+ std::cerr << "Malloc failed" << std::endl;
+ return 1;
+ }
+
+ volatile int* imem = static_cast<int *>(mem); // don't optimize out memory usage
+
+ size_t imemCount = allocationSize / sizeof(int);
+
+ std::cout << "Allocated " << allocationSize << " bytes" << std::endl;
+
+ auto seed = std::chrono::high_resolution_clock::now().time_since_epoch().count();
+ std::mt19937 mt_rand(seed);
+
+ size_t randPrintCount = 10;
+
+ // Write random numbers:
+ // * Ensures each page is resident
+ // * Avoids zeroed out pages (zRAM)
+ // * Avoids same-page merging
+ for (size_t i = 0; i < imemCount; ++i) {
+ imem[i] = mt_rand();
+
+ if (i < randPrintCount) {
+ std::cout << "Generated random value: " << imem[i] << std::endl;
+ }
+ }
+
+#if USE_MLOCKALL
+ /*
+ * Lock all pages from the address space of this process.
+ */
+ if (mlockall(MCL_CURRENT | MCL_FUTURE) != 0) {
+ std::cerr << "Mlockall failed" << std::endl;
+ return 1;
+ }
+#else
+ // Use mlock because of the predictable VmLck size.
+ // Using mlockall tends to bring in anywhere from 2-2.5GB depending on the device.
+ if (mlock(mem, allocationSize) != 0) {
+ std::cerr << "Mlock failed" << std::endl;
+ return 1;
+ }
+#endif
+
+ // Validate memory is actually resident and locked with:
+ // $> cat /proc/$(pidof iorap.stress.memory)/status | grep VmLck
+ std::cout << "Locked memory (VmLck) = " << GetProcessStatus("VmLck") << std::endl;
+
+ std::cout << "Press any key to terminate" << std::endl;
+ int any_input;
+ std::cin >> any_input;
+
+ std::cout << "Terminating..." << std::endl;
+
+ munlockall();
+ free(mem);
+
+ return 0;
+}