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
prev parent 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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