TO: Juergen Gross CC: "Greg Kroah-Hartman" CC: Stefano Stabellini CC: Wei Liu tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.19.y head: 1bd8f1c8ad2f0ad5fd897ee7e37f81b867d78b5a commit: 17ef715c0c88fe2df485fba68aa7c6c6cb3004f9 [1833/4026] xen/events: defer eoi in case of excessive number of events config: x86_64-randconfig-a005-20210504 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 8f5a2a5836cc8e4c1def2bdeb022e7b496623439) 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://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/commit/?id=17ef715c0c88fe2df485fba68aa7c6c6cb3004f9 git remote add linux-stable-rc https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git git fetch --no-tags linux-stable-rc linux-4.19.y git checkout 17ef715c0c88fe2df485fba68aa7c6c6cb3004f9 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): drivers/xen/events/events_base.c:1987:6: warning: no previous prototype for function 'xen_callback_vector' [-Wmissing-prototypes] void xen_callback_vector(void) ^ drivers/xen/events/events_base.c:1987:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void xen_callback_vector(void) ^ static 1 warning generated. >> drivers/xen/events/events_base.o: warning: objtool: xen_evtchn_cpu_dead()+0x14: unreachable instruction --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org