Hi Nicholas, I love your patch! Perhaps something to improve: [auto build test WARNING on powerpc/next] [also build test WARNING on v5.10-rc3 next-20201113] [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/Nicholas-Piggin/powerpc-interrup... base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next config: powerpc-randconfig-r035-20201111 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project a719eef73ec447b2c5fc8b70f69564a2e0f78e1e) 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 powerpc cross compiling tool for clang build # apt-get install binutils-powerpc-linux-gnu # https://github.com/0day-ci/linux/commit/36805b0ebcf1760588efad86b8b5db534... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Nicholas-Piggin/powerpc-interrupt-wrappers/20201111-183954 git checkout 36805b0ebcf1760588efad86b8b5db5344329148 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc 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 >>): DEFINE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi) ^ arch/powerpc/kernel/traps.c:1950:1: note: declare 'static' if the function is not intended to be used outside of this translation unit DEFINE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi) ^ arch/powerpc/include/asm/interrupt.h:146:19: note: expanded from macro 'DEFINE_INTERRUPT_HANDLER_NMI' __visible noinstr long func(struct pt_regs *regs) \ ^ DEFINE_INTERRUPT_HANDLER_ASYNC(performance_monitor_exception_async) ^ arch/powerpc/kernel/traps.c:1963:1: note: declare 'static' if the function is not intended to be used outside of this translation unit DEFINE_INTERRUPT_HANDLER_ASYNC(performance_monitor_exception_async) ^ arch/powerpc/include/asm/interrupt.h:118:19: note: expanded from macro 'DEFINE_INTERRUPT_HANDLER_ASYNC' __visible noinstr void func(struct pt_regs *regs) \ ^ 2 warnings generated. vim +/performance_monitor_exception_nmi +1950 arch/powerpc/kernel/traps.c 1949 1951 { 1952 nmi_enter(); 1953 1954 __this_cpu_inc(irq_stat.pmu_irqs); 1955 1956 perf_irq(regs); 1957 1958 nmi_exit(); 1959 1960 return 0; 1961 } 1962 1964 { 1965 irq_enter(); 1966 1967 __this_cpu_inc(irq_stat.pmu_irqs); 1968 1969 perf_irq(regs); 1970 1971 irq_exit(); 1972 } 1973 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org