reproduce (this is a W=1 build):
        # https://github.com/gestionlin/linux/commit/a31c4d10239e1fde1560478359630ca9bdeb4a95
        git remote add linyunsheng https://github.com/gestionlin/linux.git
        git fetch --no-tags linyunsheng page_frag_cache_part2_v3_250105
        git checkout a31c4d10239e1fde1560478359630ca9bdeb4a95
        # 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 net/