Function getCgroupsV2MemoryLimit

base/base/getMemoryAmount.cpp:16–45

{

std::optional<uint64_t> getCgroupsV2MemoryLimit()
{
#if defined(OS_LINUX)
    if (!cgroupsV2Enabled())
        return {};

    std::filesystem::path current_cgroup = cgroupV2PathOfProcess();
    if (current_cgroup.empty())
        return {};

    /// Open the bottom-most nested memory limit setting file. If there is no such file at the current
    /// level, try again at the parent level as memory settings are inherited.
    while (current_cgroup != default_cgroups_mount.parent_path())
    {
        std::ifstream setting_file(current_cgroup / "memory.max");
        if (setting_file.is_open())
        {
            uint64_t value = {};
            if (setting_file >> value)
                return {value};
            return {}; /// e.g. the cgroups default "max"
        }
        current_cgroup = current_cgroup.parent_path();
    }

    return {};
#else
    return {};
#endif
}

}