tree:   https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/core
head:   2dfdb3d20ad50e2ae2cb84cbceb0f0fc75e79e5d
commit: 66b4da2b7ae40a896693187de1296aee6974c33f [17/19] sched, rt: support schedstats for RT sched class
config: m68k-buildonly-randconfig-r002-20210910 (attached as .config)
compiler: m68k-linux-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/peterz/queue.git/commit/?id=66b4da2b7ae40a896693187de1296aee6974c33f
        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
        git checkout 66b4da2b7ae40a896693187de1296aee6974c33f
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=m68k 

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:253:6: warning: no previous prototype for 'free_rt_sched_group' [-Wmissing-prototypes]
     253 | void free_rt_sched_group(struct task_group *tg) { }
         |      ^~~~~~~~~~~~~~~~~~~
   kernel/sched/rt.c:255:5: warning: no previous prototype for 'alloc_rt_sched_group' [-Wmissing-prototypes]
     255 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent)
         |     ^~~~~~~~~~~~~~~~~~~~
   kernel/sched/rt.c:669:6: warning: no previous prototype for 'sched_rt_bandwidth_account' [-Wmissing-prototypes]
     669 | bool sched_rt_bandwidth_account(struct rt_rq *rt_rq)
         |      ^~~~~~~~~~~~~~~~~~~~~~~~~~
   kernel/sched/rt.c: In function 'update_stats_wait_start_rt':
>> kernel/sched/rt.c:1292:29: warning: variable 'p' set but not used [-Wunused-but-set-variable]
    1292 |         struct task_struct *p = NULL;
         |                             ^
   kernel/sched/rt.c: In function 'update_stats_enqueue_sleeper_rt':
   kernel/sched/rt.c:1311:29: warning: variable 'p' set but not used [-Wunused-but-set-variable]
    1311 |         struct task_struct *p = NULL;
         |                             ^
   kernel/sched/rt.c: In function 'update_stats_wait_end_rt':
   kernel/sched/rt.c:1341:29: warning: variable 'p' set but not used [-Wunused-but-set-variable]
    1341 |         struct task_struct *p = NULL;
         |                             ^


vim +/p +1292 kernel/sched/rt.c

  1287	
  1288	static inline void
  1289	update_stats_wait_start_rt(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se)
  1290	{
  1291		struct sched_statistics *stats;
> 1292		struct task_struct *p = NULL;
  1293	
  1294		if (!schedstat_enabled())
  1295			return;
  1296	
  1297		if (rt_entity_is_task(rt_se))
  1298			p = rt_task_of(rt_se);
  1299	
  1300		stats = __schedstats_from_rt_se(rt_se);
  1301		if (!stats)
  1302			return;
  1303	
  1304		__update_stats_wait_start(rq_of_rt_rq(rt_rq), p, stats);
  1305	}
  1306	

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