tree: https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/core-sched head: a2f7c8bee1740fc80a75734268b065c96d68d29b commit: 520bf37d416584c0aca5a190d922d4db145e5d91 [27/29] sched: Cgroup core-scheduling interface config: riscv-randconfig-r025-20210413 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 9829f5e6b1bca9b61efc629770d28bb9014dec45) 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 riscv cross compiling tool for clang build # apt-get install binutils-riscv64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git/commit/?... 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 520bf37d416584c0aca5a190d922d4db145e5d91 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=riscv If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): static inline void sched_core_cgroup_online(struct task_group *parent, struct task_group tg) { } ^ include/linux/sched.h:67:8: note: forward declaration of 'struct task_group' struct task_group; ^ 1 error generated. Kconfig warnings: (for reference only) WARNING: unmet direct dependencies detected for LOCKDEP Depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT && (FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86) Selected by - PROVE_LOCKING && DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT - LOCK_STAT && DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT - DEBUG_LOCK_ALLOC && DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT vim +5731 kernel/sched/core.c 5729 5730 static inline void sched_core_cgroup_free(struct task_group *tg) { } 5732 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org