Re: [rcu:rcu/test 55/64] kernel/rcu/rcutorture.c:1507:13: warning: no previous prototype for 'rcu_nocb_cpu_offload'

Re: [rcu:rcu/test 55/64] kernel/rcu/rcutorture.c:1507:13: warning: no previous prototype for 'rcu_nocb_cpu_offload'

[Paul E. McKenney]

On Fri, Sep 25, 2020 at 11:08:19AM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git rcu/test
> head:   516c2f87d0d1204a9ea1b36298283f74056a7eab
> commit: 4df5d8a622235d0b26aba92c881d190667e4d6c3 [55/64] rcutorture: Test runtime toggling of CPUs' callback offloading
> config: microblaze-randconfig-r033-20200923 (attached as .config)
> compiler: microblaze-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
>         git checkout 4df5d8a622235d0b26aba92c881d190667e4d6c3
>         # save the attached .config to linux build tree
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=microblaze 
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All warnings (new ones prefixed by >>):
> 
> >> kernel/rcu/rcutorture.c:1507:13: warning: no previous prototype for 'rcu_nocb_cpu_offload' [-Wmissing-prototypes]
>     1507 | void __weak rcu_nocb_cpu_offload(int cpu) {}
>          |             ^~~~~~~~~~~~~~~~~~~~
> >> kernel/rcu/rcutorture.c:1508:13: warning: no previous prototype for 'rcu_nocb_cpu_deoffload' [-Wmissing-prototypes]
>     1508 | void __weak rcu_nocb_cpu_deoffload(int cpu) {}
>          |             ^~~~~~~~~~~~~~~~~~~~~~

The previous prototype will be showing up later, once the code that
this is testing appears.  At which point these two lines will go away.

							Thanx, Paul

> # https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git/commit/?id=4df5d8a622235d0b26aba92c881d190667e4d6c3
> git remote add rcu https://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
> git fetch --no-tags rcu rcu/test
> git checkout 4df5d8a622235d0b26aba92c881d190667e4d6c3
> vim +/rcu_nocb_cpu_offload +1507 kernel/rcu/rcutorture.c
> 
>   1506	
> > 1507	void __weak rcu_nocb_cpu_offload(int cpu) {}
> > 1508	void __weak rcu_nocb_cpu_deoffload(int cpu) {}
>   1509	
> 
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org