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

Gui Jianfeng
2010-12-14T06:32:11Z

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>
---
block/cfq-iosched.c | 6 ------
1 files changed, 0 insertions(+), 6 deletions(-)

diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 9b186fd..c19d015 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -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;
--
1.6.5.2