reproduce (this is a W=1 build):
        # https://github.com/alexshi/linux/commit/f0d01cac9f10dfe6f6cd671dca7d02581c67587a
        git remote add alexshi https://github.com/alexshi/linux.git
        git fetch --no-tags alexshi pgtable20251212
        git checkout f0d01cac9f10dfe6f6cd671dca7d02581c67587a

        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-8.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=sparc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-8.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=sparc SHELL=/bin/bash arch/sparc/mm/ mm/