tree: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2020.03.16a head: ad7a7c12b09555e7c488ee3be512d549cd78a2c0 commit: 277258c315b7c732948e47718de02c6908d1745e [60/68] rcu-tasks: Add RCU tasks to rcutorture writer stall output config: arc-defconfig (attached as .config) compiler: arc-elf-gcc (GCC) 9.2.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross git checkout 277258c315b7c732948e47718de02c6908d1745e # save the attached .config to linux build tree GCC_VERSION=9.2.0 make.cross ARCH=arc If you fix the issue, kindly add following tag Reported-by: kbuild test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): In file included from kernel/rcu/update.c:562: kernel/rcu/tasks.h: In function 'show_rcu_tasks_gp_kthreads': 1000 | show_rcu_tasks_generic_gp_kthread(&rcu_tasks_rude, ""); | ^~~~~~~~~~~~~~ | rcu_tasks_qs kernel/rcu/tasks.h:1000:37: note: each undeclared identifier is reported only once for each function it appears in vim +1000 kernel/rcu/tasks.h 996 997 void show_rcu_tasks_gp_kthreads(void) 998 { 999 show_rcu_tasks_generic_gp_kthread(&rcu_tasks, ""); 1001 show_rcu_tasks_trace_gp_kthread(); 1002 } 1003 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org