Commit 7278c9c1 authored Dec 17, 2010 by Gui Jianfeng Committed by Jens Axboe Dec 17, 2010

cfq-iosched: don't check cfqg in choose_service_tree()



When cfq_choose_cfqg() is called in select_queue(), there must be at least one
backlogged CFQ queue waiting for dispatching, hence there must be at least one
backlogged CFQ group on service tree. So we never call choose_service_tree()
with cfqg == NULL.

Signed-off-by: Gui Jianfeng <guijianfeng@cn.fujitsu.com>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

parent a8adbe37

block/cfq-iosched.c

+0 −6

Original line number	Diff line number	Diff line
		@@ -2103,12 +2103,6 @@ static void choose_service_tree(struct cfq_data cfqd, struct cfq_group cfqg)
		unsigned group_slice;
		enum wl_prio_t original_prio = cfqd->serving_prio;

		if (!cfqg) {
		cfqd->serving_prio = IDLE_WORKLOAD;
		cfqd->workload_expires = jiffies + 1;
		return;
		}

		/* Choose next priority. RT > BE > IDLE */
		if (cfq_group_busy_queues_wl(RT_WORKLOAD, cfqd, cfqg))
		cfqd->serving_prio = RT_WORKLOAD;