Merge "libprocessgroup: Remove MemcgV2Test#ProactiveReclaimDoesntTakeForever" into main

 */

#include <cerrno>

#include <chrono>

#include <cstdio>

#include <filesystem>

#include <future>

#include <iostream>

#include <optional>

#include <random>

#include <string>

#include <vector>

#include <unistd.h>

#include <android-base/file.h>

#include <android-base/strings.h>

using android::base::ReadFileToString;

}  // anonymous namespace

class MemcgV2Test : public testing::Test {

  protected:

    void SetUp() override {

        std::optional<bool> memcgV2Enabled = isMemcgV2Enabled();

        ASSERT_NE(memcgV2Enabled, std::nullopt);

        if (!*memcgV2Enabled) GTEST_SKIP() << "Memcg v2 not enabled";

    }

};

class MemcgV2SubdirTest : public testing::Test {

  protected:

    std::optional<std::string> mRandDir;

    ASSERT_TRUE(WriteStringToFile("+memory", *mRandDir + "/cgroup.subtree_control"))

            << "Could not enable memcg under child cgroup subtree";

}

// Test for fix: mm: memcg: use larger batches for proactive reclaim

// https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=287d5fedb377ddc232b216b882723305b27ae31a

TEST_F(MemcgV2Test, ProactiveReclaimDoesntTakeForever) {

    // Not all kernels have memory.reclaim

    const std::filesystem::path reclaim(CGROUP_V2_ROOT_PATH + "/memory.reclaim");

    if (!std::filesystem::exists(reclaim)) GTEST_SKIP() << "memory.reclaim not found";

    // Use the total device memory as the amount to reclaim

    const long numPages = sysconf(_SC_PHYS_PAGES);

    const long pageSize = sysconf(_SC_PAGE_SIZE);

    ASSERT_GT(numPages, 0);

    ASSERT_GT(pageSize, 0);

    const unsigned long long totalMem =

            static_cast<unsigned long long>(numPages) * static_cast<unsigned long long>(pageSize);

    auto fut = std::async(std::launch::async,

                          [&]() { WriteStringToFile(std::to_string(totalMem), reclaim); });

    // This is a test for completion within the timeout. The command is likely to "fail" since we

    // are asking to reclaim all device memory.

    ASSERT_NE(fut.wait_for(std::chrono::seconds(20)), std::future_status::timeout);

}