Hi Hao, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on bpf-next/master] url: https://github.com/0day-ci/linux/commits/Hao-Luo/Extend-cgroup-interface-with-bpf/20220226-074615 base: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git master config: hexagon-randconfig-r023-20220226 (https://download.01.org/0day-ci/archive/20220226/202202261010.IU59MxY8-lkp@xxxxxxxxx/config) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project d271fc04d5b97b12e6b797c6067d3c96a8d7470e) 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/0day-ci/linux/commit/ee74423719e2efb4efa7a4491920c78b60024ec7 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Hao-Luo/Extend-cgroup-interface-with-bpf/20220226-074615 git checkout ee74423719e2efb4efa7a4491920c78b60024ec7 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash kernel/bpf/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> kernel/bpf/cgroup_iter.c:107:39: warning: format specifies type 'unsigned long' but the argument has type 'u64' (aka 'unsigned long long') [-Wformat] seq_printf(seq, "cgroup_id:\t%lu\n", aux->cgroup_id); ~~~ ^~~~~~~~~~~~~~ %llu >> kernel/bpf/cgroup_iter.c:101:6: warning: no previous prototype for function 'bpf_iter_cgroup_show_fdinfo' [-Wmissing-prototypes] void bpf_iter_cgroup_show_fdinfo(const struct bpf_iter_aux_info *aux, ^ kernel/bpf/cgroup_iter.c:101:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void bpf_iter_cgroup_show_fdinfo(const struct bpf_iter_aux_info *aux, ^ static >> kernel/bpf/cgroup_iter.c:111:5: warning: no previous prototype for function 'bpf_iter_cgroup_fill_link_info' [-Wmissing-prototypes] int bpf_iter_cgroup_fill_link_info(const struct bpf_iter_aux_info *aux, ^ kernel/bpf/cgroup_iter.c:111:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int bpf_iter_cgroup_fill_link_info(const struct bpf_iter_aux_info *aux, ^ static 3 warnings generated. vim +107 kernel/bpf/cgroup_iter.c 100 > 101 void bpf_iter_cgroup_show_fdinfo(const struct bpf_iter_aux_info *aux, 102 struct seq_file *seq) 103 { 104 char buf[64] = {0}; 105 106 cgroup_path_from_kernfs_id(aux->cgroup_id, buf, sizeof(buf)); > 107 seq_printf(seq, "cgroup_id:\t%lu\n", aux->cgroup_id); 108 seq_printf(seq, "cgroup_path:\t%s\n", buf); 109 } 110 > 111 int bpf_iter_cgroup_fill_link_info(const struct bpf_iter_aux_info *aux, 112 struct bpf_link_info *info) 113 { 114 info->iter.cgroup.cgroup_id = aux->cgroup_id; 115 return 0; 116 } 117 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx