reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # install loongarch cross compiling tool for clang build
        # apt-get install binutils-loongarch-linux-gnu
        git remote add openeuler https://gitee.com/openeuler/kernel.git
        git fetch --no-tags openeuler OLK-6.6
        git checkout ef015dbb4151c10d0415045f9d0fcf3dc85063d7
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=loongarch olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=loongarch SHELL=/bin/bash fs/proc/ kernel/bpf-rvi/ kernel/sched/