Re: [PATCH] cfq-iosched: reduce write depth only if sync was delayed

From: Jeff Moyer
Date: Mon Dec 07 2009 - 09:13:11 EST


Jens Axboe <jens.axboe@xxxxxxxxxx> writes:

> On Sun, Dec 06 2009, Corrado Zoccolo wrote:
>> Hi Jeff,
>> I remember you saw large performance drop on your SAN for sequential
>> writes with low_latency=1. Can you test if Shaohua's and this patch
>> fix allow to recover some bandwidth? I think that enabling the queue
>> depth ramp up only if a sync request was delayed should disable it for
>> fast hardware like yours, so you should not be seeing the slowdown any
>> more.
>
> I queued this up for post inclusion into 2.6.33, with the time_after()
> fixed.
>
> The patch was word-wrapped, btw.

So in what branch can I find this fix? Once I know that I can queue up
some tests.

Cheers,
Jeff
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