reproduce (this is a W=1 build):
        # https://github.com/amir73il/linux/commit/f602365f9bbe01bd2faf490e801fe35368fbde98
        git remote add amir73il https://github.com/amir73il/linux
        git fetch --no-tags amir73il fsnotify-perf
        git checkout f602365f9bbe01bd2faf490e801fe35368fbde98
        # 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 fs/configfs/