Hi, Thank you for the patch! Yet something to improve: [auto build test ERROR on linus/master] [also build test ERROR on v5.13-rc5 next-20210609] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/qiang-zhang-windriver-com/eventf... base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 368094df48e680fa51cedb68537408cfa64b788e config: x86_64-randconfig-a015-20210608 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project d2012d965d60c3258b3a69d024491698f8aec386) 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 x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://github.com/0day-ci/linux/commit/e11cefc5baf3f6cfb1ec8cd99b80422b6... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review qiang-zhang-windriver-com/eventfd-convert-global-percpu-eventfd_wake_count-to-ctx-percpu-eventfd_wake_count/20210609-112354 git checkout e11cefc5baf3f6cfb1ec8cd99b80422b6f592517 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): In file included from drivers/vhost/net.c:9: struct kref kref; ^ include/linux/eventfd.h:37:9: note: forward declaration of 'struct kref' struct kref kref; ^ 1 error generated. vim +37 include/linux/eventfd.h 35 36 struct eventfd_ctx { 38 wait_queue_head_t wqh; 39 /* 40 * Every time that a write(2) is performed on an eventfd, the 41 * value of the __u64 being written is added to "count" and a 42 * wakeup is performed on "wqh". A read(2) will return the "count" 43 * value to userspace, and will reset "count" to zero. The kernel 44 * side eventfd_signal() also, adds to the "count" counter and 45 * issue a wakeup. 46 */ 47 __u64 count; 48 unsigned int flags; 49 int id; 50 int __percpu *eventfd_wake_count; 51 }; 52 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org