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However, it completely fails at the purpose of > a changelog, which is to elucidate the reader as to the reasons for > doing so. How about to change the changelog as following: " In current newidle balance, the rq->idle_stamp may set to a non-zero value if it cannot pull any task. In the wakeup, it will detect the rq->idle_stamp, and updates the rq->avg_idle, then ends the CPU idle status by setting rq->idle_stamp to zero. Besides the wakeup, current code does not end the CPU idle status when a task is moved to the idle CPU, such as fork/clone, execve, or other cases. In order to fix this issue, we want to add a hook(update_rq_avg_idle()) in the enqueue_task(). With this hook, if a task is moved to the idle CPU, it will update the rq->avg_idle. Unfortunately, this hook is also called in the newidle balance:    sched_balance_newidle() --> sched_balance_rq() --> ... --> enqueue_task() If we still set rq->idle_stamp at the beginning of sched_balance_newidle(), the rq->avg_idle will not be updated correctly. In order to make it work correctly, save the idle_stamp at the beginning of sched_balance_newidle(). If newidle balance cannot pull any task, set the saved value for rq->idle_stamp. With this method, the newidle balance still work correctly, and the hook in enqueue_task() also works correctly. " Thanks Huang Shijie