Hi Yafang, kernel test robot noticed the following build errors: [auto build test ERROR on bpf-next/master] url: https://github.com/intel-lab-lkp/linux/commits/Yafang-Shao/cgroup-psi-Init-PSI-of-root-cgroup-to-psi_system/20231222-193221 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master patch link: https://lore.kernel.org/r/20231222113102.4148-2-laoar.shao%40gmail.com patch subject: [PATCH bpf-next 1/4] cgroup, psi: Init PSI of root cgroup to psi_system config: arm-defconfig (https://download.01.org/0day-ci/archive/20231223/202312231522.VWy0LXXY-lkp@xxxxxxxxx/config) compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project.git f28c006a5895fc0e329fe15fead81e37457cb1d1) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231223/202312231522.VWy0LXXY-lkp@xxxxxxxxx/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@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202312231522.VWy0LXXY-lkp@xxxxxxxxx/ All errors (new ones prefixed by >>): >> kernel/cgroup/cgroup.c:169:15: error: use of undeclared identifier 'psi_system' .cgrp.psi = &psi_system, ^ 1 error generated. vim +/psi_system +169 kernel/cgroup/cgroup.c 165 166 /* the default hierarchy */ 167 struct cgroup_root cgrp_dfl_root = { 168 .cgrp.rstat_cpu = &cgrp_dfl_root_rstat_cpu, > 169 .cgrp.psi = &psi_system, 170 }; 171 EXPORT_SYMBOL_GPL(cgrp_dfl_root); 172 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki