Hi Quentin, FYI, the error/warning still remains. tree: https://github.com/ammarfaizi2/linux-block google/android/kernel/common/android-4.19-stable head: 90a691fca4c2525068d9908ac203e9f09e4e33c0 commit: eead51495c8760858c32d9ad0332ffc94397aa82 [204/9999] ANDROID: GKI: sched: stub sched_isolate symbols config: x86_64-randconfig-a011 (https://download.01.org/0day-ci/archive/20220122/202201220740.3itLwKmy-lk...) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/ammarfaizi2/linux-block/commit/eead51495c8760858c32d9a... git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block git fetch --no-tags ammarfaizi2-block google/android/kernel/common/android-4.19-stable git checkout eead51495c8760858c32d9ad0332ffc94397aa82 # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/nvmem/ kernel/sched/ 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 >>): 8 | int sched_isolate_cpu(int cpu) | ^~~~~~~~~~~~~~~~~ 14 | int sched_unisolate_cpu_unlocked(int cpu) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ 20 | int sched_unisolate_cpu(int cpu) | ^~~~~~~~~~~~~~~~~~~ 26 | int set_task_boost(int boost, u64 period) | ^~~~~~~~~~~~~~ vim +/sched_isolate_cpu +8 kernel/sched/stubs.c 7 9 { 10 return -EINVAL; 11 } 12 EXPORT_SYMBOL_GPL(sched_isolate_cpu); 13 15 { 16 return -EINVAL; 17 } 18 EXPORT_SYMBOL_GPL(sched_unisolate_cpu_unlocked); 19 21 { 22 return -EINVAL; 23 } 24 EXPORT_SYMBOL_GPL(sched_unisolate_cpu); 25 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org