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Re: [Xen-devel] Time goes backwards in dom0 in xen-unstable

To: "Tian, Kevin" <kevin.tian@xxxxxxxxx>, Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>, "Xen-Devel (E-mail)" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] Time goes backwards in dom0 in xen-unstable
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Wed, 15 Apr 2009 10:18:53 +0100
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On 15/04/2009 08:51, "Tian, Kevin" <kevin.tian@xxxxxxxxx> wrote:

> We revised our plan here, after realizing not-negligible effort to
> enable RTC emulation. Instead we want to turn to an alternative
> that hpet broadcast is always enabled once available (current
> situation is to always give up if no MSI delivery support), and
> then disable it on the fly (disable HPET interrupt and reduce
> max_cstate to a level not requiring broadcast) once detecting
> user trying to enable UIE/PIE/AIE on RTC. That way is far
> simpler and makes cpuidle really available on most platforms
> with HPET (true for most with VT support), in the meantime
> not breaking occasional usage on RTC interrupt.
> Will you accept such patch which handles mostly about policy? :-)
> We'll try to send it out today.

It's got a better chance than RTC emulation. I'll certainly consider it.

 -- Keir

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