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Re: [Xen-devel] VT is comically slow

To: Rik van Riel <riel@xxxxxxxxxx>
Subject: Re: [Xen-devel] VT is comically slow
From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date: Mon, 3 Jul 2006 09:58:01 +0100
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On 3 Jul 2006, at 09:48, Rik van Riel wrote:

Looking at it a bit more closely, it appears that postgresql
doing disk IO from inside a fully virtualized domain totally
kills the CPU.

It gets so bad that a simple "dmesg" takes 10-20 seconds to start,
and after that it spews data maybe 7 or 8 lines every other second.
Actually slower than serial console...

This is totally unusable :(

Might you be emulating PIO? That would certainly suck. The device model is supposed to support (virtual) DMA though.

 -- Keir

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