tree: https://android.googlesource.com/kernel/common android12-5.10 head: 43edfc892e926ffa364f591dea27729ff4a60f3d commit: 5ada76d0563798c02c4217d61d85cfacc1279a7a [3217/3240] ANDROID: sched/pause: prevent wake up paused cpus config: arm64-randconfig-r036-20210114 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project 6077d55381a6aa3e947ef7abdc36a7515c598c8a) 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 arm64 cross compiling tool for clang build # apt-get install binutils-aarch64-linux-gnu git remote add android-common https://android.googlesource.com/kernel/common git fetch --no-tags android-common android12-5.10 git checkout 5ada76d0563798c02c4217d61d85cfacc1279a7a # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=arm64 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 >>): kernel/smp.c:444:6: warning: no previous prototype for function 'flush_smp_call_function_from_idle' [-Wmissing-prototypes] void flush_smp_call_function_from_idle(void) ^ kernel/smp.c:444:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void flush_smp_call_function_from_idle(void) ^ static if (s2idle_state == S2IDLE_STATE_ENTER || cpu_active(cpu)) ^ if (s2idle_state == S2IDLE_STATE_ENTER || cpu_active(cpu)) ^ 1 warning and 2 errors generated. vim +/s2idle_state +957 kernel/smp.c 941 942 /** 943 * wake_up_all_idle_cpus - break all cpus out of idle 944 * wake_up_all_idle_cpus try to break all cpus which is in idle state even 945 * including idle polling cpus, for non-idle cpus, we will do nothing 946 * for them. 947 */ 948 void wake_up_all_idle_cpus(void) 949 { 950 int cpu; 951 952 preempt_disable(); 953 for_each_online_cpu(cpu) { 954 if (cpu == smp_processor_id()) 955 continue; 956 958 wake_up_if_idle(cpu); 959 } 960 preempt_enable(); 961 } 962 EXPORT_SYMBOL_GPL(wake_up_all_idle_cpus); 963 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org