reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # https://git.kernel.org/pub/scm/linux/kernel/git/vbabka/linux.git/commit/?id=8f3b3550b6d09f88b11b9d89eb1d6a215c48bf98
        git remote add vbabka https://git.kernel.org/pub/scm/linux/kernel/git/vbabka/linux.git
        git fetch --no-tags vbabka slub-percpu-caches-v4r1-BROKEN
        git checkout 8f3b3550b6d09f88b11b9d89eb1d6a215c48bf98
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-13.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=openrisc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-13.2.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=openrisc SHELL=/bin/bash mm/