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From: Ric Wheeler <rwheeler@redhat.com>
To: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>,
	Matthew Wilcox <matthew@wil.cx>,
	Boaz Harrosh <bharrosh@panasas.com>,
	linux-scsi@vger.kernel.org
Subject: Re: [DO NOT APPLY] sd take advantage of rotation speed
Date: Mon, 28 Jul 2008 09:36:26 -0400	[thread overview]
Message-ID: <488DCB5A.9080105@redhat.com> (raw)
In-Reply-To: <yq1d4m575je.fsf@sermon.lab.mkp.net>

Martin K. Petersen wrote:
>>>>>> "Jens" == Jens Axboe <jens.axboe@oracle.com> writes:
>>>>>>             
>
> Jens> Uhm, but it IS "a blatant layering violation", it's doing things
> Jens> from the wrong side up :-)
>
> I also disagree with mucking with the elevator directly in sd.c.
>
> The whole point of my I/O hints work is to expose the I/O topology in
> a generic fashion so that upper layers can take advantage of them.
>
> I'll post a new batch of those patches shortly...
>
>   

One other thought - is there a way to give non-rotational devices also 
some indication of latency? (FLASH is slower than enterprise SSD is 
slower than DRAM ramdisk for example)?

ric


  parent reply	other threads:[~2008-07-28 13:38 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-06-19 16:03 [DO NOT APPLY] sd take advantage of rotation speed Matthew Wilcox
2008-06-19 17:12 ` Mike Anderson
2008-06-19 18:10   ` Matthew Wilcox
2008-06-22 12:16 ` Boaz Harrosh
2008-06-22 13:19   ` Matthew Wilcox
2008-06-22 13:27     ` Boaz Harrosh
2008-06-22 13:38 ` James Bottomley
2008-06-22 14:03   ` Matthew Wilcox
2008-06-22 14:41     ` Martin K. Petersen
2008-06-22 18:44       ` Matthew Wilcox
2008-06-25  2:06         ` Martin K. Petersen
2008-06-22 17:26     ` James Bottomley
2008-06-25 13:47 ` Jens Axboe
2008-06-25 13:57   ` Jens Axboe
2008-06-25 14:24   ` Ric Wheeler
2008-06-25 16:25     ` Boaz Harrosh
2008-06-25 16:57       ` Jens Axboe
2008-06-25 17:20         ` Matthew Wilcox
2008-06-25 17:26           ` Jens Axboe
2008-06-25 17:34             ` Matthew Wilcox
2008-06-25 17:43               ` James Bottomley
2008-06-25 17:53                 ` Matthew Wilcox
2008-06-25 18:01                   ` Jens Axboe
2008-06-25 18:06                   ` James Bottomley
2008-06-25 17:59               ` Jens Axboe
2008-06-25 18:06             ` Martin K. Petersen
2008-06-25 18:12               ` Jens Axboe
2008-07-28 13:36               ` Ric Wheeler [this message]
2008-07-28 14:10                 ` James Bottomley
2008-07-28 14:31                 ` Martin K. Petersen
2008-07-31 21:00                   ` Grant Grundler
2008-07-31 21:19                     ` Andrew Patterson
2008-07-31 22:26                     ` Ric Wheeler
2008-07-31 23:44                       ` Grant Grundler

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