Merge "Revert "Use mem cgroups in libprocessgroup if they're available"" am: e8a75e8f

using namespace std::chrono_literals;

// Uncomment line below use memory cgroups for keeping track of (forked) PIDs

// #define USE_MEMCG 1

#define MEM_CGROUP_PATH "/dev/memcg/apps"

#define MEM_CGROUP_TASKS "/dev/memcg/apps/tasks"

#define ACCT_CGROUP_PATH "/acct"

};

static const char* getCgroupRootPath() {

#ifdef USE_MEMCG

    static const char* cgroup_root_path = NULL;

    std::call_once(init_path_flag, [&]() {

            // Check if mem cgroup is mounted, only then check for write-access to avoid

                    ACCT_CGROUP_PATH : MEM_CGROUP_PATH;

            });

    return cgroup_root_path;

#else

    return ACCT_CGROUP_PATH;

#endif

}

static int convertUidToPath(char *path, size_t size, uid_t uid)

    mount cgroup none /dev/memcg memory

    # app mem cgroups, used by activity manager, lmkd and zygote

    mkdir /dev/memcg/apps/ 0755 system system

    # cgroup for system_server and surfaceflinger

    mkdir /dev/memcg/system 0755 system system

    start ueventd