Re: [PATCH 11/24] io-controller: Introduce group idling

From: Gui Jianfeng
Date: Thu Aug 27 2009 - 21:15:54 EST


Vivek Goyal wrote:
...
> @@ -2201,13 +2362,44 @@ void elv_ioq_completed_request(struct request_queue *q, struct request *rq)
> * mean seek distance, give them a chance to run instead
> * of idling.
> */
> - if (elv_ioq_slice_used(ioq) || elv_ioq_class_idle(ioq))
> + if (elv_ioq_slice_used(ioq) || elv_ioq_class_idle(ioq)) {
> + /*
> + * This is the last empty queue in the group and it
> + * has consumed its slice. If we expire it right away
> + * group might loose its share. Wait for an extra
> + * group_idle period for a request before queue
> + * expires.
> + */
> + if (elv_iog_should_idle(ioq)) {
> + elv_iog_arm_slice_timer(q, iog, 1);
> + goto done;
> + }
> +

Hi Vivek,

I think we shouldn't arm idle timer on iog again, if it's already on.

Signed-off-by: Gui Jianfeng <guijianfeng@xxxxxxxxxxxxxx>
---
block/elevator-fq.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/block/elevator-fq.c b/block/elevator-fq.c
index a4161c2..04f646f 100644
--- a/block/elevator-fq.c
+++ b/block/elevator-fq.c
@@ -3116,7 +3116,8 @@ void elv_ioq_completed_request(struct request_queue *q, struct request *rq)
* group_idle period for a request before queue
* expires.
*/
- if (elv_iog_should_idle(ioq)) {
+ if (elv_iog_should_idle(ioq) &&
+ !elv_iog_wait_busy(iog)) {
elv_iog_arm_slice_timer(q, iog, 1);
goto done;
}
--
1.5.4.rc3



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