Hi Wei, [FYI, it's a private test report for your RFC patch.] [auto build test WARNING on net-next/master] url: https://github.com/0day-ci/linux/commits/Wei-Wang/implement-kthread-based... base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git e059c6f340f6fccadd3db9993f06d4cc51305804 config: arm64-randconfig-r024-20200914 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project b2c32c90bab09a6e2c1f370429db26017a182143) 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 arm64 cross compiling tool for clang build # apt-get install binutils-aarch64-linux-gnu # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): unsigned long *__alloc_thread_bitmap(struct net_device *netdev, int *bits) ^ net/core/net-sysfs.c:541:1: note: declare 'static' if the function is not intended to be used outside of this translation unit unsigned long *__alloc_thread_bitmap(struct net_device *netdev, int *bits) ^ static 1 warning generated. # https://github.com/0day-ci/linux/commit/ba7d63f1040aedba86f70713af085d863... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Wei-Wang/implement-kthread-based-napi-poll/20200915-013651 git checkout ba7d63f1040aedba86f70713af085d86322fee62 vim +/__alloc_thread_bitmap +541 net/core/net-sysfs.c 540 542 { 543 struct napi_struct *n; 544 545 *bits = 0; 546 list_for_each_entry(n, &netdev->napi_list, dev_list) 547 (*bits)++; 548 549 return kmalloc_array(BITS_TO_LONGS(*bits), sizeof(unsigned long), 550 GFP_ATOMIC | __GFP_ZERO); 551 } 552 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org