Hi Yafang, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on bpf-next/master] url: https://github.com/intel-lab-lkp/linux/commits/Yafang-Shao/mm-percpu-fix-incorrect-size-in-pcpu_obj_full_size/20230202-094352 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master patch link: https://lore.kernel.org/r/20230202014158.19616-7-laoar.shao%40gmail.com patch subject: [PATCH bpf-next 6/7] bpf: introduce bpf_mem_alloc_size() config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20230202/202302021258.By6JZK71-lkp@xxxxxxxxx/config) compiler: m68k-linux-gcc (GCC) 12.1.0 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://github.com/intel-lab-lkp/linux/commit/996f3e2ac4dca054396d0f37ffe8ddb97fc4212f git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Yafang-Shao/mm-percpu-fix-incorrect-size-in-pcpu_obj_full_size/20230202-094352 git checkout 996f3e2ac4dca054396d0f37ffe8ddb97fc4212f # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k olddefconfig COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash kernel/bpf/ If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> kernel/bpf/memalloc.c:227:15: warning: no previous prototype for 'bpf_mem_cache_size' [-Wmissing-prototypes] 227 | unsigned long bpf_mem_cache_size(struct bpf_mem_cache *c, void *obj) | ^~~~~~~~~~~~~~~~~~ vim +/bpf_mem_cache_size +227 kernel/bpf/memalloc.c 226 > 227 unsigned long bpf_mem_cache_size(struct bpf_mem_cache *c, void *obj) 228 { 229 unsigned long size; 230 231 if (!obj) 232 return 0; 233 234 if (c->percpu_size) { 235 size = percpu_size(((void **)obj)[1]); 236 size += ksize(obj); 237 return size; 238 } 239 240 return ksize(obj); 241 } 242 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests