C++ rq_set_fifo_time函数代码示例

static void
zen_merged_requests(struct request_queue *q, struct request *req,
                    struct request *next)
{
	/*
	 * if next expires before rq, assign its expire time to arq
	 * and move into next position (next will be deleted) in fifo
	 */
	if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
		if (time_before(rq_fifo_time(next), rq_fifo_time(req))) {
			list_move(&req->queuelist, &next->queuelist);
			rq_set_fifo_time(req, rq_fifo_time(next));
		}
	}

	/* next request is gone */
	rq_fifo_clear(next);
}

/* 
   This function does 3 tasks:
   1 check if next expires before req, is so set expire time of req to be the expire time of next
   2 delete next from async fifo queue
   3 check if merged req size >= bundle_size; if so, delete req from async fifo queue, reinit and insert it to bundle queue
 */
static void
flash_merged_requests(struct request_queue *q, struct request *req,
			 struct request *next)
{
	struct flash_data *fd = q->elevator->elevator_data;
	// const int data_type = !rq_is_sync(req);
	// FIXME:
	const int data_type = rq_data_dir(req);

	/*
	 * if next expires before rq, assign its expire time to rq
	 * and move into next position (next will be deleted) in fifo
	 */
	// TODO: why need to check if async queue is empty here?
	if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
		if (time_before(rq_fifo_time(next), rq_fifo_time(req))) {
			list_move(&req->queuelist, &next->queuelist);
			rq_set_fifo_time(req, rq_fifo_time(next));
		}
	}

	/* delete next */
	rq_fifo_clear(next);
	
	/* task 3 only kick into bundle queue if req is async */
	if(req->__data_len >= fd->bundle_size && data_type == 1)
	{
		/* did both delete and init */
		rq_fifo_clear(req); 
		list_add_tail(&req->queuelist, &fd->bundle_list);
		
		#ifdef DEBUG_FLASH
		printk("req of type %d of size %d is inserted to bundle queue\n", data_type, req->__data_len);
		#endif
	}

}

/*
 * row_add_request() - Add request to the scheduler
 * @q:	requests queue
 * @rq:	request to add
 *
 */
static void row_add_request(struct request_queue *q,
			    struct request *rq)
{
	struct row_data *rd = (struct row_data *)q->elevator->elevator_data;
	struct row_queue *rqueue = RQ_ROWQ(rq);
	s64 diff_ms;
	bool queue_was_empty = list_empty(&rqueue->fifo);

	list_add_tail(&rq->queuelist, &rqueue->fifo);
	rd->nr_reqs[rq_data_dir(rq)]++;
	rqueue->nr_req++;
	rq_set_fifo_time(rq, jiffies); /* for statistics*/

	if (rq->cmd_flags & REQ_URGENT) {
		WARN_ON(1);
		blk_dump_rq_flags(rq, "");
		rq->cmd_flags &= ~REQ_URGENT;
	}

	if (row_queues_def[rqueue->prio].idling_enabled) {
		if (rd->rd_idle_data.idling_queue_idx == rqueue->prio &&
		    hrtimer_active(&rd->rd_idle_data.hr_timer)) {
			if (hrtimer_try_to_cancel(
				&rd->rd_idle_data.hr_timer) >= 0) {
				row_log_rowq(rd, rqueue->prio,
				    "Canceled delayed work on %d",
				    rd->rd_idle_data.idling_queue_idx);
				rd->rd_idle_data.idling_queue_idx =
					ROWQ_MAX_PRIO;
			}
		}
		diff_ms = ktime_to_ms(ktime_sub(ktime_get(),
				rqueue->idle_data.last_insert_time));
		if (unlikely(diff_ms < 0)) {
			pr_err("%s(): time delta error: diff_ms < 0",
				__func__);
			rqueue->idle_data.begin_idling = false;
			return;
		}
		if (diff_ms < rd->rd_idle_data.freq_ms) {
			rqueue->idle_data.begin_idling = true;
			row_log_rowq(rd, rqueue->prio, "Enable idling");
		} else {
			rqueue->idle_data.begin_idling = false;
			row_log_rowq(rd, rqueue->prio, "Disable idling (%ldms)",
				(long)diff_ms);
		}

		rqueue->idle_data.last_insert_time = ktime_get();
	}
	if (row_queues_def[rqueue->prio].is_urgent &&
	    !rd->pending_urgent_rq && !rd->urgent_in_flight) {
		/* Handle High Priority queues */
		if (rqueue->prio < ROWQ_REG_PRIO_IDX &&
		    rd->last_served_ioprio_class != IOPRIO_CLASS_RT &&
		    queue_was_empty) {
			row_log_rowq(rd, rqueue->prio,
				"added (high prio) urgent request");
			rq->cmd_flags |= REQ_URGENT;
			rd->pending_urgent_rq = rq;
		} else  if (row_rowq_unserved(rd, rqueue->prio)) {
			/* Handle Regular priotity queues */
			row_log_rowq(rd, rqueue->prio,
				"added urgent request (total on queue=%d)",
				rqueue->nr_req);
			rq->cmd_flags |= REQ_URGENT;
			rd->pending_urgent_rq = rq;
		}
	} else
		row_log_rowq(rd, rqueue->prio,
			"added request (total on queue=%d)", rqueue->nr_req);
}