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Re: [Xen-devel] [RFC] [PATCH] use "reliable" tsc properly when available

To: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>, "Xen-Devel (E-mail)" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [RFC] [PATCH] use "reliable" tsc properly when available, but verify
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Tue, 29 Sep 2009 18:17:34 +0100
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On 29/09/2009 16:51, "Dan Magenheimer" <dan.magenheimer@xxxxxxxxxx> wrote:

> This proposed patch is really only important for Phase
> II, but given all the confusion around whether tsc is
> reliable/safe/constant/nonstop on various machines,
> I think it might be good to get code into Xen --
> sooner rather than later -- that "measures" this
> so we can confirm if the promises made by processor
> and system vendors are (or are not) being delivered.
> 
> Does that make more sense?

That makes it a nice-to-have. But not nice enough to have all CPUs groove
off for 2ms every once in a while, imo.

 -- Keir



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