cfq-iosched: improve sync vs async workloads (3ed9a296) · Commits · e / devices / android_kernel_teracube_2e

block/cfq-iosched.c

+18 −13

Original line number	Diff line number	Diff line
		@@ -96,6 +96,7 @@ struct cfq_data {
		struct hlist_head *cfq_hash;

		int rq_in_driver;
		int sync_flight;
		int hw_tag;

		/*
		@@ -911,11 +912,15 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
		*/
		static void cfq_dispatch_insert(request_queue_t q, struct request rq)
		{
		struct cfq_data *cfqd = q->elevator->elevator_data;
		struct cfq_queue *cfqq = RQ_CFQQ(rq);

		cfq_remove_request(rq);
		cfqq->dispatched++;
		elv_dispatch_sort(q, rq);

		if (cfq_cfqq_sync(cfqq))
		cfqd->sync_flight++;
		}

		/*
		@@ -1100,27 +1105,24 @@ static int cfq_dispatch_requests(request_queue_t *q, int force)
		while ((cfqq = cfq_select_queue(cfqd)) != NULL) {
		int max_dispatch;

		if (cfqd->busy_queues > 1) {
		/*
		* So we have dispatched before in this round, if the
		* next queue has idling enabled (must be sync), don't
		* allow it service until the previous have completed.
		*/
		if (cfqd->rq_in_driver && cfq_cfqq_idle_window(cfqq) &&
		dispatched)
		max_dispatch = cfqd->cfq_quantum;
		if (cfq_class_idle(cfqq))
		max_dispatch = 1;

		if (cfqq->dispatched >= max_dispatch) {
		if (cfqd->busy_queues > 1)
		break;
		if (cfqq->dispatched >= cfqd->cfq_quantum)
		if (cfqq->dispatched >= 4 * max_dispatch)
		break;
		}

		if (cfqd->sync_flight && !cfq_cfqq_sync(cfqq))
		break;

		cfq_clear_cfqq_must_dispatch(cfqq);
		cfq_clear_cfqq_wait_request(cfqq);
		del_timer(&cfqd->idle_slice_timer);

		max_dispatch = cfqd->cfq_quantum;
		if (cfq_class_idle(cfqq))
		max_dispatch = 1;

		dispatched += __cfq_dispatch_requests(cfqd, cfqq, max_dispatch);
		}

		@@ -1767,6 +1769,9 @@ static void cfq_completed_request(request_queue_t q, struct request rq)
		cfqd->rq_in_driver--;
		cfqq->dispatched--;

		if (cfq_cfqq_sync(cfqq))
		cfqd->sync_flight--;

		if (!cfq_class_idle(cfqq))
		cfqd->last_end_request = now;