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Re: [Xen-devel] TPR write optimization (even improves 2003 sp2)

To: James Harper <james.harper@xxxxxxxxxxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] TPR write optimization (even improves 2003 sp2)
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Wed, 07 Jan 2009 08:57:05 +0000
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On 07/01/2009 02:59, "James Harper" <james.harper@xxxxxxxxxxxxxxxx> wrote:

> Is there such a facility available under Intel CPU's, other than the
> latest 'flex priority' stuff which I am about to read up on?

The LOCK MOV CR0 trick doesn't work on Intel CPUs. You should have space to
patch in a JMP instruction though, and then you can shadow the TPR value and
only do actual writes when the value changes.

 -- Keir



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