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From: Tao Ma <tm@tao.ma>
To: Christoph Hellwig <hch@infradead.org>
Cc: Shaohua Li <shaohua.li@intel.com>,
	lkml <linux-kernel@vger.kernel.org>,
	Jens Axboe <jaxboe@fusionio.com>,
	Maxim Patlasov <maxim.patlasov@gmail.com>,
	Vivek Goyal <vgoyal@redhat.com>,
	Corrado Zoccolo <czoccolo@gmail.com>
Subject: Re: [patch]cfq-iosched: delete deep seeky queue idle logic
Date: Fri, 16 Sep 2011 22:50:17 +0800	[thread overview]
Message-ID: <4E736229.4080300@tao.ma> (raw)
In-Reply-To: <20110916140809.GA7026@infradead.org>

On 09/16/2011 10:08 PM, Christoph Hellwig wrote:
> On Fri, Sep 16, 2011 at 05:54:51PM +0800, Tao Ma wrote:
>> This year's FAST has a paper named "A Scheduling Framework That Makes
>> Any Disk Schedulers Non-Work-Conserving Solely Based on Request
>> Characteristics". It has described this situation and suggests a new
>> scheduler named "stream scheduler" to resolve this. But I am not sure
>> whether CFQ can work like that or not.
> 
> As usual I suspect the best thing is to just use noop for these kinds of
> cases.  E.g. when you use xfs with the filestreams options you'll get
> patterns pretty similar to that in the initial post  - that is
> intentional as it is generally use to place them into different areas
> of a complex RAID array.  Any scheduler "smarts" will just help to break these
> I/O streams.
yeah, actually the paper does show that the performance of cfq is worse
than noop in this case. ;) See section 3.4 if you are interested.

Thanks
Tao

      reply	other threads:[~2011-09-16 14:50 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-16  3:09 [patch]cfq-iosched: delete deep seeky queue idle logic Shaohua Li
2011-09-16  6:04 ` Corrado Zoccolo
2011-09-16  6:40   ` Shaohua Li
2011-09-16 19:25     ` Corrado Zoccolo
2011-09-21 11:16       ` Shaohua Li
2011-09-23 13:24         ` Vivek Goyal
2011-09-25  7:34           ` Corrado Zoccolo
2011-09-27 13:08             ` Vivek Goyal
2011-09-26  0:51           ` Shaohua Li
2011-09-27 13:11             ` Vivek Goyal
     [not found]         ` <CADX3swq0qURdi7VYLAVbsAmX5psPrzq-uvbqANsnLkHO0xcOMQ@mail.gmail.com>
2011-09-26  0:55           ` Shaohua Li
2011-09-27  6:07             ` Corrado Zoccolo
2011-09-27  6:33               ` Shaohua Li
2011-09-28  7:09                 ` Corrado Zoccolo
2011-09-16 13:24   ` Vivek Goyal
2011-09-16 13:37   ` Vivek Goyal
2011-09-16  9:54 ` Tao Ma
2011-09-16 14:08   ` Christoph Hellwig
2011-09-16 14:50     ` Tao Ma [this message]

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