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The TASK_ON_RQ_QUEUED is set in activate_task().   1.) For this active task, if the sched_change makes it dequeue_task()/enqueue_task() on       current CPU, it's okay. Since current CPU is not in the newidle, the "rq->idle_stamp" is 0 at this case.       This patch works fine.  2.) For this active task, if the sched_change makes it dequeue_task()/enqueue_task() on an another CPU,       it's okay too.          2.1) If the another CPU's idle_stamp is 0, the another CPU is busy now.                  The sched_change works fine with this patch.          2.2) If the another CPU's idle_stamp is not 0, the sched_change also works fine with this patch.                 Since the sched_change is breaking the idle state of the another CPU by moving an active                 task to an idle CPU. It makes sense. Thanks Huang Shijie