Hi, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on tip/sched/core] [also build test WARNING on v5.12-rc7 next-20210413] [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/qianjun-kernel-gmail-com/sched-f... base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 4aed8aa41524a1fc6439171881c2bb7ace197528 config: i386-randconfig-s001-20210413 (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce: # apt-get install sparse # sparse version: v0.6.3-280-g2cd6d34e-dirty # https://github.com/0day-ci/linux/commit/dbe8fdaf74553572909be6f118565862c... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review qianjun-kernel-gmail-com/sched-fair-Reduce-unnecessary-check-preempt-in-the-sched-tick/20210413-212057 git checkout dbe8fdaf74553572909be6f118565862c4cdfac5 # save the attached .config to linux build tree make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=i386 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; sparse warnings: (new ones prefixed by >>) kernel/sched/fair.c:871:34: sparse: sparse: incorrect type in argument 1 (different address spaces) @@ expected struct sched_entity *se @@ got struct sched_entity [noderef] __rcu * @@ kernel/sched/fair.c:871:34: sparse: expected struct sched_entity *se kernel/sched/fair.c:871:34: sparse: got struct sched_entity [noderef] __rcu * kernel/sched/fair.c:4386:37: sparse: expected struct task_struct *tsk kernel/sched/fair.c:4386:37: sparse: got struct task_struct [noderef] __rcu *curr kernel/sched/fair.c:7000:38: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct task_struct *curr @@ got struct task_struct [noderef] __rcu *curr @@ kernel/sched/fair.c:7000:38: sparse: expected struct task_struct *curr kernel/sched/fair.c:7000:38: sparse: got struct task_struct [noderef] __rcu *curr kernel/sched/fair.c:7251:38: sparse: sparse: incorrect type in initializer (different address spaces) @@ expected struct task_struct *curr @@ got struct task_struct [noderef] __rcu *curr @@ kernel/sched/fair.c:7251:38: sparse: expected struct task_struct *curr kernel/sched/fair.c:7251:38: sparse: got struct task_struct [noderef] __rcu *curr kernel/sched/fair.c:5383:35: sparse: sparse: marked inline, but without a definition kernel/sched/fair.c: note: in included file: kernel/sched/sched.h:1887:9: sparse: sparse: incompatible types in comparison expression (different address spaces): kernel/sched/sched.h:1887:9: sparse: struct task_struct [noderef] __rcu * kernel/sched/sched.h:1887:9: sparse: struct task_struct * kernel/sched/sched.h:1732:25: sparse: sparse: incompatible types in comparison expression (different address spaces): kernel/sched/sched.h:1732:25: sparse: struct task_struct [noderef] __rcu * kernel/sched/sched.h:1732:25: sparse: struct task_struct * kernel/sched/sched.h:1732:25: sparse: sparse: incompatible types in comparison expression (different address spaces): kernel/sched/sched.h:1732:25: sparse: struct task_struct [noderef] __rcu * kernel/sched/sched.h:1732:25: sparse: struct task_struct * vim +4386 kernel/sched/fair.c 4373 4374 /* 4375 * Preempt the current task with a newly woken task if needed: 4376 */ 4377 static void 4378 check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) 4379 { 4380 unsigned long ideal_runtime, delta_exec; 4381 struct sched_entity *se; 4382 struct rq *rq = rq_of(cfs_rq); 4383 s64 delta; 4384 4385 /* If the TIF_NEED_RESCHED has been set, it is no need to check again */ 4387 return; 4388 4389 ideal_runtime = sched_slice(cfs_rq, curr); 4390 delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime; 4391 if (delta_exec > ideal_runtime) { 4392 resched_curr(rq_of(cfs_rq)); 4393 /* 4394 * The current task ran long enough, ensure it doesn't get 4395 * re-elected due to buddy favours. 4396 */ 4397 clear_buddies(cfs_rq, curr); 4398 return; 4399 } 4400 4401 /* 4402 * Ensure that a task that missed wakeup preemption by a 4403 * narrow margin doesn't have to wait for a full slice. 4404 * This also mitigates buddy induced latencies under load. 4405 */ 4406 if (delta_exec < sysctl_sched_min_granularity) 4407 return; 4408 4409 se = __pick_first_entity(cfs_rq); 4410 delta = curr->vruntime - se->vruntime; 4411 4412 if (delta < 0) 4413 return; 4414 4415 if (delta > ideal_runtime) 4416 resched_curr(rq_of(cfs_rq)); 4417 } 4418 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org