tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: e7b08814b16b80a0bf76eeca16317f8c2ed23b8c commit: e4fe5dd6f26f74233e217d9dd351adc3e5165bb9 [4053/14131] rcu-tasks: Further refactor RCU-tasks to allow adding more variants config: x86_64-randconfig-a015-20200529 (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 2d068e534f1671459e1b135852c1b3c10502e929) 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 # install x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu git checkout e4fe5dd6f26f74233e217d9dd351adc3e5165bb9 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): In file included from kernel//rcu/update.c:588: void rcu_tasks_postscan(void) ^ kernel//rcu/tasks.h:257:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void rcu_tasks_postscan(void) ^ static 1 warning generated. vim +/rcu_tasks_postscan +257 kernel//rcu/tasks.h 255 256 /* Processing between scanning taskslist and draining the holdout list. */ 258 { 259 /* 260 * Wait for tasks that are in the process of exiting. This 261 * does only part of the job, ensuring that all tasks that were 262 * previously exiting reach the point where they have disabled 263 * preemption, allowing the later synchronize_rcu() to finish 264 * the job. 265 */ 266 synchronize_srcu(&tasks_rcu_exit_srcu); 267 } 268 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org