reproduce (this is a W=1 build):
        # https://github.com/rgushchin/linux/commit/d5e513cdf1ec233fa62389576f6ddb1c730d9994
        git remote add rgushchin https://github.com/rgushchin/linux.git
        git fetch --no-tags rgushchin lru_note_cost.1
        git checkout d5e513cdf1ec233fa62389576f6ddb1c730d9994
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 olddefconfig
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash mm/