tree: https://github.com/zen-kernel/zen-kernel 5.15/prjc head: 88afbbeeefd1e9ceca6efea72562fca5fc546daf commit: 5f4249233a80dbfc638ec1eaa9b68f1039399f66 [199/239] sched/alt: [Sync] 2f064a59a11f sched: Change task_struct::state config: i386-randconfig-a002-20211118 (attached as .config) 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/zen-kernel/zen-kernel/commit/5f4249233a80dbfc638ec1eaa... git remote add zen https://github.com/zen-kernel/zen-kernel git fetch --no-tags zen 5.15/prjc git checkout 5f4249233a80dbfc638ec1eaa9b68f1039399f66 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=i386 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 >>): kernel/sched/alt_core.c:830:6: warning: no previous prototype for function 'resched_curr' [-Wmissing-prototypes] void resched_curr(struct rq *rq) ^ kernel/sched/alt_core.c:830:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void resched_curr(struct rq *rq) ^ static kernel/sched/alt_core.c:853:6: warning: no previous prototype for function 'resched_cpu' [-Wmissing-prototypes] void resched_cpu(int cpu) ^ kernel/sched/alt_core.c:853:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void resched_cpu(int cpu) ^ static kernel/sched/alt_core.c:1744:6: warning: no previous prototype for function 'sched_set_stop_task' [-Wmissing-prototypes] void sched_set_stop_task(int cpu, struct task_struct *stop) ^ kernel/sched/alt_core.c:1744:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void sched_set_stop_task(int cpu, struct task_struct *stop) ^ static void idle_task_exit(void) ^ kernel/sched/alt_core.c:6229:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void idle_task_exit(void) ^ static int sched_cpu_activate(unsigned int cpu) ^ kernel/sched/alt_core.c:6439:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int sched_cpu_activate(unsigned int cpu) ^ static int sched_cpu_deactivate(unsigned int cpu) ^ kernel/sched/alt_core.c:6478:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int sched_cpu_deactivate(unsigned int cpu) ^ static int sched_cpu_starting(unsigned int cpu) ^ kernel/sched/alt_core.c:6542:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int sched_cpu_starting(unsigned int cpu) ^ static int sched_cpu_wait_empty(unsigned int cpu) ^ kernel/sched/alt_core.c:6562:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int sched_cpu_wait_empty(unsigned int cpu) ^ static int sched_cpu_dying(unsigned int cpu) ^ kernel/sched/alt_core.c:6604:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int sched_cpu_dying(unsigned int cpu) ^ static kernel/sched/alt_core.c:6851:16: warning: variable 'preempt_disable_ip' set but not used [-Wunused-but-set-variable] unsigned long preempt_disable_ip; ^ kernel/sched/alt_core.c:1100:19: warning: unused function 'hrtick_enabled' [-Wunused-function] static inline int hrtick_enabled(struct rq *rq) ^ 11 warnings generated. vim +/idle_task_exit +6229 kernel/sched/alt_core.c cb06db4ef97b1e Alfred Chen 2019-08-19 6223 cb06db4ef97b1e Alfred Chen 2019-08-19 6224 #ifdef CONFIG_HOTPLUG_CPU cb06db4ef97b1e Alfred Chen 2019-08-19 6225 /* cb06db4ef97b1e Alfred Chen 2019-08-19 6226 * Ensures that the idle task is using init_mm right before its CPU goes cb06db4ef97b1e Alfred Chen 2019-08-19 6227 * offline. cb06db4ef97b1e Alfred Chen 2019-08-19 6228 */ cb06db4ef97b1e Alfred Chen 2019-08-19 @6229 void idle_task_exit(void) cb06db4ef97b1e Alfred Chen 2019-08-19 6230 { cb06db4ef97b1e Alfred Chen 2019-08-19 6231 struct mm_struct *mm = current->active_mm; cb06db4ef97b1e Alfred Chen 2019-08-19 6232 cb06db4ef97b1e Alfred Chen 2019-08-19 6233 BUG_ON(current != this_rq()->idle); cb06db4ef97b1e Alfred Chen 2019-08-19 6234 cb06db4ef97b1e Alfred Chen 2019-08-19 6235 if (mm != &init_mm) { cb06db4ef97b1e Alfred Chen 2019-08-19 6236 switch_mm(mm, &init_mm, current); cb06db4ef97b1e Alfred Chen 2019-08-19 6237 finish_arch_post_lock_switch(); cb06db4ef97b1e Alfred Chen 2019-08-19 6238 } cb06db4ef97b1e Alfred Chen 2019-08-19 6239 cb06db4ef97b1e Alfred Chen 2019-08-19 6240 /* finish_cpu(), as ran on the BP, will clean up the active_mm state */ cb06db4ef97b1e Alfred Chen 2019-08-19 6241 } cb06db4ef97b1e Alfred Chen 2019-08-19 6242 :::::: The code at line 6229 was first introduced by commit :::::: cb06db4ef97b1e99a0350d328e6044f374941410 Project C v5.7.5-r2 :::::: TO: Alfred Chen <cchalpha(a)gmail.com&gt; :::::: CC: Alfred Chen <cchalpha(a)gmail.com&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org