tree: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2021.08.12a head: 3d4b7b3ca5de1d3669890684c3e60d3dad6ea468 commit: cc2392da423274c116d72777d11344f67230a50b [53/72] EXP cpu: Check for clock going backwards in CPU-hotplug progress checks config: powerpc-randconfig-r013-20210815 (attached as .config) compiler: powerpc-linux-gcc (GCC) 11.2.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/com... git remote add rcu https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git git fetch --no-tags rcu dev.2021.08.12a git checkout cc2392da423274c116d72777d11344f67230a50b # save the attached .config to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=powerpc SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): powerpc-linux-ld: kernel/cpu.o: in function `cpu_hp_check_delay.part.0': cpu.c:(.text+0x1654): undefined reference to `__udivdi3' --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org