Hi Ming, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on tip/irq/core] [also build test WARNING on next-20210813] [cannot apply to block/for-next linux/master linus/master v5.14-rc5] [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/Ming-Lei/genirq-affinity-abstrac... base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 04c2721d3530f0723b4c922a8fa9f26b202a20de config: hexagon-randconfig-r041-20210814 (attached as .config) compiler: clang version 12.0.0 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 # https://github.com/0day-ci/linux/commit/759f72186bfdd5c3ba8b53ac0749cf7ba... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Ming-Lei/genirq-affinity-abstract-new-API-from-managed-irq-affinity-spread/20210814-203741 git checkout 759f72186bfdd5c3ba8b53ac0749cf7ba930012c # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=hexagon 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 >>): >> lib/group_cpus.c:344:17: warning: no previous prototype for function 'group_cpus_evenly' [-Wmissing-prototypes] struct cpumask *group_cpus_evenly(unsigned int numgrps) ^ lib/group_cpus.c:344:1: note: declare 'static' if the function is not intended to be used outside of this translation unit struct cpumask *group_cpus_evenly(unsigned int numgrps) ^ static 1 warning generated. vim +/group_cpus_evenly +344 lib/group_cpus.c 328 329 /** 330 * group_cpus_evenly - Group all CPUs evenly per NUMA/CPU locality 331 * @numgrps: number of groups 332 * 333 * Return: cpumask array if successful, NULL otherwise. And each element 334 * includes CPUs assigned to this group 335 * 336 * Try to put close CPUs from viewpoint of CPU and NUMA locality into 337 * same group, and run two-stage grouping: 338 * 1) allocate present CPUs on these groups evenly first 339 * 2) allocate other possible CPUs on these groups evenly 340 * 341 * We guarantee in the resulted grouping that all CPUs are covered, and 342 * no same CPU is assigned to different groups 343 */ > 344 struct cpumask *group_cpus_evenly(unsigned int numgrps)