Re: kernel/rcu/tasks.h:1031:6: warning: no previous prototype for 'show_rcu_tasks_gp_kthreads'

[Paul E. McKenney]

On Tue, Apr 20, 2021 at 02:56:30PM +0800, kernel test robot wrote:
> Hi Paul,
> 
> FYI, the error/warning still remains.
> 
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   7af08140979a6e7e12b78c93b8625c8d25b084e2
> commit: e21408ceec2de5be418efa39feb1e2c00f824a72 rcu-tasks: Add RCU tasks to rcutorture writer stall output
> date:   12 months ago
> config: h8300-allnoconfig (attached as .config)
> compiler: h8300-linux-gcc (GCC) 9.3.0
> 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/torvalds/linux.git/commit/?id=e21408ceec2de5be418efa39feb1e2c00f824a72
>         git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>         git fetch --no-tags linus master
>         git checkout e21408ceec2de5be418efa39feb1e2c00f824a72
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross W=1 ARCH=h8300 
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@xxxxxxxxx>

Good catch, fixed with attribution by adding "static inline".

							Thanx, Paul

> All warnings (new ones prefixed by >>):
> 
>    In file included from kernel/rcu/update.c:587:
> >> kernel/rcu/tasks.h:1031:6: warning: no previous prototype for 'show_rcu_tasks_gp_kthreads' [-Wmissing-prototypes]
>     1031 | void show_rcu_tasks_gp_kthreads(void) {}
>          |      ^~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> 
> vim +/show_rcu_tasks_gp_kthreads +1031 kernel/rcu/tasks.h
> 
>   1028	
>   1029	#else /* #ifdef CONFIG_TASKS_RCU_GENERIC */
>   1030	static inline void rcu_tasks_bootup_oddness(void) {}
> > 1031	void show_rcu_tasks_gp_kthreads(void) {}
> 
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx