tree: https://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git rcu/dev head: be4d4c3ba8c4ceeba9dc9df4de5451c7261161f3 commit: bdfa2dd80919bc4636fcf606cd21b606d361fd16 [2/5] rcu/nocb: Move rcu_nocb_is_setup to rcu_state config: x86_64-randconfig-a015 (https://download.01.org/0day-ci/archive/20220217/202202170811.xZp85edb-lk...) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.g... git remote add frederic-dynticks https://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git git fetch --no-tags frederic-dynticks rcu/dev git checkout bdfa2dd80919bc4636fcf606cd21b606d361fd16 # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash kernel/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): In file included from kernel/rcu/tree.c:4858: kernel/rcu/tree_nocb.h: In function 'rcu_init_nohz': 1157 | bool need_rcu_nocb_mask = false; | ^~~~~~~~~~~~~~~~~~ vim +/need_rcu_nocb_mask +1157 kernel/rcu/tree_nocb.h dfcb27540213e8 Frederic Weisbecker 2021-05-19 1153 dfcb27540213e8 Frederic Weisbecker 2021-05-19 1154 void __init rcu_init_nohz(void) dfcb27540213e8 Frederic Weisbecker 2021-05-19 1155 { dfcb27540213e8 Frederic Weisbecker 2021-05-19 1156 int cpu; dfcb27540213e8 Frederic Weisbecker 2021-05-19 @1157 bool need_rcu_nocb_mask = false; dfcb27540213e8 Frederic Weisbecker 2021-05-19 1158 struct rcu_data *rdp; dfcb27540213e8 Frederic Weisbecker 2021-05-19 1159 :::::: The code at line 1157 was first introduced by commit :::::: dfcb27540213e8061ecffacd4bd8ed54a310a7b0 rcu/nocb: Start moving nocb code to its own plugin file :::::: TO: Frederic Weisbecker <frederic(a)kernel.org&gt; :::::: CC: Paul E. McKenney <paulmck(a)kernel.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org