sched_stat: Update sched_info_queue/dequeue() code comments

}

/*

 * Called when a process is dequeued from the active array and given

 * the cpu.  We should note that with the exception of interactive

 * tasks, the expired queue will become the active queue after the active

 * queue is empty, without explicitly dequeuing and requeuing tasks in the

 * expired queue.  (Interactive tasks may be requeued directly to the

 * active queue, thus delaying tasks in the expired queue from running;

 * see scheduler_tick()).

 *

 * Though we are interested in knowing how long it was from the *first* time a

 * We are interested in knowing how long it was from the *first* time a

 * task was queued to the time that it finally hit a cpu, we call this routine

 * from dequeue_task() to account for possible rq->clock skew across cpus. The

 * delta taken on each cpu would annul the skew.

}

/*

 * Called when a process is queued into either the active or expired

 * array.  The time is noted and later used to determine how long we

 * had to wait for us to reach the cpu.  Since the expired queue will

 * become the active queue after active queue is empty, without dequeuing

 * and requeuing any tasks, we are interested in queuing to either. It

 * is unusual but not impossible for tasks to be dequeued and immediately

 * requeued in the same or another array: this can happen in sched_yield(),

 * set_user_nice(), and even load_balance() as it moves tasks from runqueue

 * to runqueue.

 *

 * This function is only called from enqueue_task(), but also only updates

 * the timestamp if it is already not set.  It's assumed that

 * sched_info_dequeued() will clear that stamp when appropriate.