reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux.git/commit/?id=476529e56cba3ab0efd64bca5e40d7e4b8b2085c
        git remote add aegl https://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux.git
        git fetch --no-tags aegl get_cpu_cacheinfo_level
        git checkout 476529e56cba3ab0efd64bca5e40d7e4b8b2085c
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash arch/x86/kernel/cpu/resctrl/