[peterz-queue:sched/flat-2026-06-04 58/62] kernel/sched/debug.c:274:2: error: call to undeclared function '__sched_cgroup_mode_update'; ISO C99 and later do not support implicit function declarations

[kernel test robot <lkp@intel.com>]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/flat-2026-06-04
head:   b89fcd232db2b7117a3255be623eeb4c67ece726
commit: 582f7ee48dc53ebe117cf24e3a2b2102b25dcbd7 [58/62] sched/fair: Add cgroup_mode: up
config: x86_64-randconfig-014-20260605 (https://download.01.org/0day-ci/archive/20260606/202606061224.6SlMZvGc-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260606/202606061224.6SlMZvGc-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202606061224.6SlMZvGc-lkp@intel.com/

All errors (new ones prefixed by >>):

   In file included from kernel/sched/build_utility.c:71:
>> kernel/sched/debug.c:274:2: error: call to undeclared function '__sched_cgroup_mode_update'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     274 |         __sched_cgroup_mode_update(mode);
         |         ^
   1 error generated.


vim +/__sched_cgroup_mode_update +274 kernel/sched/debug.c

   256	
   257	static ssize_t sched_dynamic_write(struct file *filp, const char __user *ubuf,
   258					   size_t cnt, loff_t *ppos)
   259	{
   260		char buf[16];
   261		int mode;
   262	
   263		if (cnt > 15)
   264			cnt = 15;
   265	
   266		if (copy_from_user(buf, ubuf, cnt))
   267			return -EFAULT;
   268	
   269		buf[cnt] = 0;
   270		mode = sched_dynamic_mode(strstrip(buf));
   271		if (mode < 0)
   272			return mode;
   273	
 > 274		__sched_cgroup_mode_update(mode);
   275		sched_dynamic_update(mode);
   276	
   277		*ppos += cnt;
   278	
   279		return cnt;
   280	}
   281	

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki