tree: https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git rcu/next head: 7323bc24b9c5f4d11e9f926eb1d0f3f674f3bd1d commit: 675d3ca52626bac52da2c6ddaec94dd1a3724f0f [34/42] rcutorture: Make grace-period kthread report match RCU flavor being tested config: x86_64-kexec (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce (this is a W=1 build): git checkout 675d3ca52626bac52da2c6ddaec94dd1a3724f0f # save the attached .config to linux build tree make W=1 ARCH=x86_64 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 >>): In file included from kernel/rcu/update.c:578: 601 | static inline void show_rcu_tasks_classic_gp_kthread(void) { } | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from kernel/rcu/update.c:49: kernel/rcu/rcu.h:537:6: note: previous declaration of 'show_rcu_tasks_classic_gp_kthread' was here 537 | void show_rcu_tasks_classic_gp_kthread(void); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from kernel/rcu/update.c:578: kernel/rcu/tasks.h:1222:20: error: static declaration of 'show_rcu_tasks_trace_gp_kthread' follows non-static declaration 1222 | static inline void show_rcu_tasks_trace_gp_kthread(void) {} | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from kernel/rcu/update.c:49: kernel/rcu/rcu.h:539:6: note: previous declaration of 'show_rcu_tasks_trace_gp_kthread' was here 539 | void show_rcu_tasks_trace_gp_kthread(void); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ # 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 rcu/next git checkout 675d3ca52626bac52da2c6ddaec94dd1a3724f0f vim +/show_rcu_tasks_classic_gp_kthread +601 kernel/rcu/tasks.h 25246fc83155b25 Paul E. McKenney 2020-04-05 599 e21408ceec2de5b Paul E. McKenney 2020-03-16 600 #else /* #ifdef CONFIG_TASKS_RCU */ 01c7eedbd55bd3d Paul E. McKenney 2020-08-25 @601 static inline void show_rcu_tasks_classic_gp_kthread(void) { } 25246fc83155b25 Paul E. McKenney 2020-04-05 602 void exit_tasks_rcu_start(void) { } 25246fc83155b25 Paul E. McKenney 2020-04-05 603 void exit_tasks_rcu_finish(void) { exit_tasks_rcu_finish_trace(current); } e21408ceec2de5b Paul E. McKenney 2020-03-16 604 #endif /* #else #ifdef CONFIG_TASKS_RCU */ c84aad765406c4c Paul E. McKenney 2020-03-02 605 :::::: The code at line 601 was first introduced by commit :::::: 01c7eedbd55bd3dd9ca881a979a99c6a0571011f rcu-tasks: Prevent complaints of unused show_rcu_tasks_classic_gp_kthread() :::::: TO: Paul E. McKenney <paulmck(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