From 3586e917f2c7df769d173c4ec99554cb40a911e5 Mon Sep 17 00:00:00 2001 From: Gui Jianfeng Date: Thu, 26 Nov 2009 09:14:11 +0100 Subject: [PATCH] cfq: Make use of service count to estimate the rb_key offset For the moment, different workload cfq queues are put into different service trees. But CFQ still uses "busy_queues" to estimate rb_key offset when inserting a cfq queue into a service tree. I think this isn't appropriate, and it should make use of service tree count to do this estimation. This patch is for for-2.6.33 branch. Signed-off-by: Gui Jianfeng Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 1bcbd8c7989..467981e19d7 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -600,11 +600,15 @@ cfq_find_next_rq(struct cfq_data *cfqd, struct cfq_queue *cfqq, static unsigned long cfq_slice_offset(struct cfq_data *cfqd, struct cfq_queue *cfqq) { + struct cfq_rb_root *service_tree; + + service_tree = service_tree_for(cfqq_prio(cfqq), cfqq_type(cfqq), cfqd); + /* * just an approximation, should be ok. */ - return (cfqd->busy_queues - 1) * (cfq_prio_slice(cfqd, 1, 0) - - cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); + return service_tree->count * (cfq_prio_slice(cfqd, 1, 0) - + cfq_prio_slice(cfqd, cfq_cfqq_sync(cfqq), cfqq->ioprio)); } /*