[kbuild-all] [linux-next:master 1017/5794] include/asm-generic/mmu_context.h:60:2: error: implicit declaration of function 'switch_mm'

tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 92edc4aef86780a8ad01b092c6d6630bb3cb423d commit: 94f89922e1e094f57a143965059a3e477f3f2fdc [1017/5794] asm-generic: add generic MMU versions of mmu context functions config: h8300-randconfig-r036-20201113 (attached as .config) compiler: h8300-linux-gcc (GCC) 9.3.0 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://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commi... git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout 94f89922e1e094f57a143965059a3e477f3f2fdc # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=h8300 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 >>): In file included from ./arch/h8300/include/generated/asm/mmu_context.h:1, from include/linux/mmu_context.h:5, from kernel/sched/sched.h:54, from kernel/sched/core.c:13: include/asm-generic/mmu_context.h: In function 'activate_mm': 60 | switch_mm(prev_mm, next_mm, current); | ^~~~~~~~~ kernel/sched/core.c: In function 'ttwu_stat': kernel/sched/core.c:2419:13: warning: variable 'rq' set but not used [-Wunused-but-set-variable] 2419 | struct rq *rq; | ^~ cc1: some warnings being treated as errors -- In file included from ./arch/h8300/include/generated/asm/mmu_context.h:1, from include/linux/mmu_context.h:5, from kernel/sched/sched.h:54, from kernel/sched/loadavg.c:9: include/asm-generic/mmu_context.h: In function 'activate_mm': 60 | switch_mm(prev_mm, next_mm, current); | ^~~~~~~~~ cc1: some warnings being treated as errors -- In file included from ./arch/h8300/include/generated/asm/mmu_context.h:1, from include/linux/mmu_context.h:5, from kernel/sched/sched.h:54, from kernel/sched/rt.c:6: include/asm-generic/mmu_context.h: In function 'activate_mm': 60 | switch_mm(prev_mm, next_mm, current); | ^~~~~~~~~ kernel/sched/rt.c: At top level: kernel/sched/rt.c:668:6: warning: no previous prototype for 'sched_rt_bandwidth_account' [-Wmissing-prototypes] 668 | bool sched_rt_bandwidth_account(struct rt_rq *rt_rq) | ^~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: some warnings being treated as errors vim +/switch_mm +60 include/asm-generic/mmu_context.h 50 51 /** 52 * activate_mm - called after exec switches the current task to a new mm, to switch to it 53 * @prev_mm: previous mm of this task 54 * @next_mm: new mm 55 */ 56 #ifndef activate_mm 57 static inline void activate_mm(struct mm_struct *prev_mm, 58 struct mm_struct *next_mm) 59 { 61 } 62 #endif 63 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org