From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jeremy Fitzhardinge <jeremy@goop.org>
Subject: Re: [PATCH] replace rdtsc emulation-vs-native xen boot
	option with per-domain (hypervisor part)
Date: Mon, 28 Sep 2009 16:10:05 -0700
Message-ID: <4AC1424D.8070008@goop.org>
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To: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: "Xen-Devel (E-mail)" <xen-devel@lists.xensource.com>, Keir Fraser <keir.fraser@eu.citrix.com>
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On 09/28/09 15:43, Dan Magenheimer wrote:
> PV ones too.  An app doesn't have any idea (and doesn't
> and shouldn't care) if it is running on a PV or HVM domain.
>   

Well, it shouldn't be enabled by default.  That slows down all rdtsc
operations for the benefit of very niche applications.  The Xen
clocksource assumes that rdtsc is fast, unemulated and in need of
correction.

If someone really needs an artificial tsc, then they can enable the
option for themselves.

    J