Hi Xiyu, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on vhost/linux-next] [also build test WARNING on v5.14-rc1 next-20210716] [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/Xiyu-Yang/vhost_net-Convert-from-atomic_t-to-refcount_t-on-vhost_net_ubuf_ref-refcount/20210718-101502 base: https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next config: i386-randconfig-a015-20210718 (attached as .config) compiler: gcc-10 (Ubuntu 10.3.0-1ubuntu1~20.04) 10.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/8aaf246d79e6bb03b71d9a1a13289f919aa34215 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Xiyu-Yang/vhost_net-Convert-from-atomic_t-to-refcount_t-on-vhost_net_ubuf_ref-refcount/20210718-101502 git checkout 8aaf246d79e6bb03b71d9a1a13289f919aa34215 # save the attached .config to linux build tree make W=1 ARCH=i386 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): drivers/vhost/net.c: In function 'vhost_net_ubuf_put': >> drivers/vhost/net.c:253:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement] 253 | int r = refcount_read(&ubufs->refcount); | ^~~ vim +253 drivers/vhost/net.c 249 250 static int vhost_net_ubuf_put(struct vhost_net_ubuf_ref *ubufs) 251 { 252 refcount_dec(&ubufs->refcount); > 253 int r = refcount_read(&ubufs->refcount); 254 if (unlikely(!r)) 255 wake_up(&ubufs->wait); 256 return r; 257 } 258 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org