tree:   https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/core-sched
head:   ead81f232b5b31ab6240a719ff3bad564c3f0e4c
commit: 6f7eefbb382e8c5fa56180f8cd5becb5f882a3d6 [10/11] sched/fair: Snapshot the min_vruntime of CPUs on force idle
config: powerpc64-randconfig-r011-20210108 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 5c951623bc8965fa1e89660f2f5f4a2944e4981a)
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 powerpc64 cross compiling tool for clang build
        # apt-get install binutils-powerpc64-linux-gnu
        # https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/commit/?id=6f7eefbb382e8c5fa56180f8cd5becb5f882a3d6
        git remote add peterz-queue https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git
        git fetch --no-tags peterz-queue sched/core-sched
        git checkout 6f7eefbb382e8c5fa56180f8cd5becb5f882a3d6
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc64 

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/sched/fair.c:10777:6: warning: no previous prototype for function 'task_vruntime_update' [-Wmissing-prototypes]
   void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi)
        ^
   kernel/sched/fair.c:10777:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi)
   ^
   static 
   1 warning generated.


vim +/task_vruntime_update +10777 kernel/sched/fair.c

 10776	
 10777	void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi)
 10778	{
 10779		struct sched_entity *se = &p->se;
 10780	
 10781		if (p->sched_class != &fair_sched_class)
 10782			return;
 10783	
 10784		se_fi_update(se, rq->core->core_forceidle_seq, in_fi);
 10785	}
 10786	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org