Hi "Björn,

I love your patch! Yet something to improve:

[auto build test ERROR on 4e99d115d865d45e17e83478d757b58d8fa66d3c]

url:    https://github.com/0day-ci/linux/commits/Bj-rn-T-pel/Introduce-preferred-busy-polling/20210929-234934
base:   4e99d115d865d45e17e83478d757b58d8fa66d3c
config: riscv-randconfig-r042-20210929 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project dc6e8dfdfe7efecfda318d43a06fae18b40eb498)
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://github.com/0day-ci/linux/commit/f481c00164924dd5d782a92cc67897cc7f804502
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Bj-rn-T-pel/Introduce-preferred-busy-polling/20210929-234934
        git checkout f481c00164924dd5d782a92cc67897cc7f804502
        # save the attached .config to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from fs/select.c:32:
   In file included from include/net/busy_poll.h:15:
   In file included from include/linux/netdevice.h:37:
   In file included from include/linux/ethtool.h:18:
   In file included from include/uapi/linux/ethtool.h:19:
   In file included from include/linux/if_ether.h:19:
   include/linux/skbuff.h:4622:26: error: implicit declaration of function 'skb_ext_add' [-Werror,-Wimplicit-function-declaration]
                   u64 *kcov_handle_ptr = skb_ext_add(skb, SKB_EXT_KCOV_HANDLE);
                                          ^
   include/linux/skbuff.h:4622:43: error: use of undeclared identifier 'SKB_EXT_KCOV_HANDLE'
                   u64 *kcov_handle_ptr = skb_ext_add(skb, SKB_EXT_KCOV_HANDLE);
                                                           ^
   include/linux/skbuff.h:4631:21: error: implicit declaration of function 'skb_ext_find' [-Werror,-Wimplicit-function-declaration]
           u64 *kcov_handle = skb_ext_find(skb, SKB_EXT_KCOV_HANDLE);
                              ^
   include/linux/skbuff.h:4631:39: error: use of undeclared identifier 'SKB_EXT_KCOV_HANDLE'
           u64 *kcov_handle = skb_ext_find(skb, SKB_EXT_KCOV_HANDLE);
                                                ^
   In file included from fs/select.c:32:
>> include/net/busy_poll.h:150:38: error: no member named 'napi_id' in 'struct sk_buff'
           __sk_mark_napi_id_once_xdp(sk, skb->napi_id);
                                          ~~~  ^
   5 errors generated.


vim +150 include/net/busy_poll.h

   145	
   146	/* variant used for unconnected sockets */
   147	static inline void sk_mark_napi_id_once(struct sock *sk,
   148						const struct sk_buff *skb)
   149	{
 > 150		__sk_mark_napi_id_once_xdp(sk, skb->napi_id);
   151	}
   152	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org