Re: [PATCH 0/4] cfq-iosched: policy fixes

[Jens Axboe <jens.axboe@oracle.com>]

On Tue, Nov 24 2009, Corrado Zoccolo wrote:
> Hi Jens,
> I've collected some bugfixes to the for-2.6.33 branch.
> Excluding the NCQ policy fix, that I'm resending with improved changelog,
> the bugs were found by Vivek while investingating performance drops
> or unfairness while testing cgroups. Nevertheless, those fixes have
> general impact, so they should go in before cgroup code is merged:
> * no-idle preemption logic was both under/over preempting.
>    it should preempt only if the active queue is idling due to
>    no-idle service tree empty
> * seeky queues with large depth could steal too much bandwidth to
>    low depth ones, so they will be marked as idling, and have exclusive
>    access to disk for their time share
> * the idling logic had some corner cases in which idling was not enabled,
>   even if it should have been, caused by rq_noidle and rq_in_driver checks.
>   Those were adjusted to better match the original intention.

Thanks Corrado, applied all 4!

-- 
Jens Axboe