tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   8ab774587903771821b59471cc723bba6d893942
commit: b027789e5e50494c2325cc70c8642e7fd6059479 sched/fair: Prevent dead task groups from regaining cfs_rq's
date:   5 days ago
config: arm-randconfig-r031-20211116 (attached as .config)
compiler: arm-linux-gnueabi-gcc (GCC) 11.2.0
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=b027789e5e50494c2325cc70c8642e7fd6059479
        git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
        git fetch --no-tags linus master
        git checkout b027789e5e50494c2325cc70c8642e7fd6059479
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=arm 

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/rt.c:257:6: warning: no previous prototype for 'unregister_rt_sched_group' [-Wmissing-prototypes]
     257 | void unregister_rt_sched_group(struct task_group *tg) { }
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~
   kernel/sched/rt.c:259:6: warning: no previous prototype for 'free_rt_sched_group' [-Wmissing-prototypes]
     259 | void free_rt_sched_group(struct task_group *tg) { }
         |      ^~~~~~~~~~~~~~~~~~~
   kernel/sched/rt.c:261:5: warning: no previous prototype for 'alloc_rt_sched_group' [-Wmissing-prototypes]
     261 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
         |     ^~~~~~~~~~~~~~~~~~~~
   kernel/sched/rt.c:675:6: warning: no previous prototype for 'sched_rt_bandwidth_account' [-Wmissing-prototypes]
     675 | bool sched_rt_bandwidth_account(struct rt_rq *rt_rq)
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/unregister_rt_sched_group +257 kernel/sched/rt.c

   256	
 > 257	void unregister_rt_sched_group(struct task_group *tg) { }
   258	

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