From d58b85e1e891cd842d6e183f5d94d06a4fd0122c Mon Sep 17 00:00:00 2001 From: Vivek Goyal Date: Fri, 10 Jul 2009 10:20:30 +0200 Subject: cfq-iosched: no need to keep track of busy_rt_queues o Get rid of busy_rt_queues infrastructure. Looks like it is redundant. o Once an RT queue gets request it will preempt any of the BE or IDLE queues immediately. Otherwise this queue will be put on service tree and scheduler will anyway select this queue before any of the BE or IDLE queue. Hence looks like there is no need to keep track of how many busy RT queues are currently on service tree. Signed-off-by: Vivek Goyal Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 23 ----------------------- 1 file changed, 23 deletions(-) (limited to 'block') diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 93693bf6083e..ca0d7e71324b 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -134,11 +134,6 @@ struct cfq_data { struct rb_root prio_trees[CFQ_PRIO_LISTS]; unsigned int busy_queues; - /* - * Used to track any pending rt requests so we can pre-empt current - * non-RT cfqq in service when this value is non-zero. - */ - unsigned int busy_rt_queues; int rq_in_driver[2]; int sync_flight; @@ -653,8 +648,6 @@ static void cfq_add_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) BUG_ON(cfq_cfqq_on_rr(cfqq)); cfq_mark_cfqq_on_rr(cfqq); cfqd->busy_queues++; - if (cfq_class_rt(cfqq)) - cfqd->busy_rt_queues++; cfq_resort_rr_list(cfqd, cfqq); } @@ -678,8 +671,6 @@ static void cfq_del_cfqq_rr(struct cfq_data *cfqd, struct cfq_queue *cfqq) BUG_ON(!cfqd->busy_queues); cfqd->busy_queues--; - if (cfq_class_rt(cfqq)) - cfqd->busy_rt_queues--; } /* @@ -1184,20 +1175,6 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd) if (cfq_slice_used(cfqq) && !cfq_cfqq_must_dispatch(cfqq)) goto expire; - /* - * If we have a RT cfqq waiting, then we pre-empt the current non-rt - * cfqq. - */ - if (!cfq_class_rt(cfqq) && cfqd->busy_rt_queues) { - /* - * We simulate this as cfqq timed out so that it gets to bank - * the remaining of its time slice. - */ - cfq_log_cfqq(cfqd, cfqq, "preempt"); - cfq_slice_expired(cfqd, 1); - goto new_queue; - } - /* * The active queue has requests and isn't expired, allow it to * dispatch. -- cgit v1.2.2