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From: Jeff Moyer <jmoyer@redhat.com>
Subject: Re: direct-io regression [Was: How to track down abysmal performance
	ata - raid1 - crypto - vg/lv - xfs]
References: <20100804073546.GA7494@comet.dominikbrodowski.net>
	<20100804085039.GA11671@infradead.org>
	<20100804091317.GA27779@isilmar-3.linta.de>
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	<20100804073546.GA7494@comet.dominikbrodowski.net>
	<201008041116.09822@zmi.at>
	<20100804102526.GB13766@isilmar-3.linta.de>
	<15446.1280953986@localhost>
	<20100805093100.GA3001@comet.dominikbrodowski.net>
	<20100805113240.GA29846@think>
Date: Thu, 05 Aug 2010 14:58:37 -0400
In-Reply-To: <20100805113240.GA29846@think> (Chris Mason's message of "Thu, 5
	Aug 2010 07:32:40 -0400")
Message-ID: <x49tyn8c2ea.fsf@segfault.boston.devel.redhat.com>
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To: Chris Mason <chris.mason@oracle.com>
Cc: Michael Monnerie <michael.monnerie@is.it-management.at>, linux-raid@vger.kernel.org, Valdis.Kletnieks@vt.edu, linux-kernel@vger.kernel.org, Dominik Brodowski <linux@dominikbrodowski.net>, xfs@oss.sgi.com, Christoph Hellwig <hch@infradead.org>, dm-devel@redhat.com, josef@redhat.com

Chris Mason <chris.mason@oracle.com> writes:

> But, I'm surprised your drive is doing 8K dio reads at 16MB/s, that
> seems a little high.  

I'm not sure why you think that.  We're talking about a plain old SATA
disk, right?  I can get 40-50MB/s on my systems for 8KB O_DIRECT reads.
What am I missing?

Cheers,
Jeff

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