Flexible I/O Tester development
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From: Jens Axboe <axboe@kernel.dk>
To: Werner Fischer <devlists@wefi.net>
Cc: Jeff Moyer <jmoyer@redhat.com>,
	"fio@vger.kernel.org" <fio@vger.kernel.org>
Subject: Re: Linux I/O stack design question
Date: Thu, 08 Sep 2011 14:39:25 +0200	[thread overview]
Message-ID: <4E68B77D.10400@kernel.dk> (raw)
In-Reply-To: <1315231292.2140.62.camel@werner-t410>

On 2011-09-05 16:01, Werner Fischer wrote:
> On Don, 2011-09-01 at 15:13 -0600, Jens Axboe wrote:
>> [...]
>> I mean that every device should plug in at the same place. There are
>> definite up and down sides to plugging in at the stacking level and
>> bypassing the IO scheduler. So you have to weight the pros and cons
>> before doing that. We need to fix this. Drivers doing that lose out on
>> other features in the name of a bit more performance, that's just not
>> acceptable.
> 
> I have updated the diagram according to all of your hints:
> http://www.thomas-krenn.com/de/wikiDE/images/0/07/Linux-IO-Stack.png
> 
> I had also some off-list discussion with Florian Haas, who convinced me
> that the file systems are below of the page cache. I hope this is now
> correct.

Not sure I'd agree with that, I'd place the page cache between the fs
and the storage layer.

-- 
Jens Axboe


  reply	other threads:[~2011-09-08 12:39 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-01 12:33 Linux I/O stack design question Werner Fischer
2011-09-01 14:19 ` Jeff Moyer
2011-09-01 20:14   ` Werner Fischer
2011-09-01 20:17     ` Jens Axboe
2011-09-01 20:27       ` Werner Fischer
2011-09-01 21:13         ` Jens Axboe
2011-09-05 14:01           ` Werner Fischer
2011-09-08 12:39             ` Jens Axboe [this message]
2011-09-12  6:36               ` Werner Fischer
2011-09-27 14:06                 ` Martin Steigerwald
2012-03-06 10:46                   ` Announce: Linux I/O stack diagram (was: Re: Linux I/O stack design question) Werner Fischer

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