Message-ID: <47267832.1060003@zytor.com>
Date: Mon, 29 Oct 2007 17:17:54 -0700
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Glauber de Oliveira Costa <gcosta@redhat.com>
CC: linux-kernel@vger.kernel.org, tglx@linutronix.de, rusty@rustcorp.com.au,
       jeremy@goop.org, --cc@redhat.com, mingo@elte.hu, avi@quramnet.com,
       kvm-devel@lists.sourceforge.net,
       Glauber de Oliveira Costa <glauber@t60.localdomain>
Subject: Re: [PATCH] raise tsc clocksource rating
References: <11936994092607-git-send-email-gcosta@redhat.com>
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Glauber de Oliveira Costa wrote:
> From: Glauber de Oliveira Costa <glauber@t60.localdomain>
> 
> tsc is very good time source (when it does not have drifts, does not
> change it's frequency, i.e. when it works), so it should have its rating
> raised to a value greater than, or equal 400.
> 
> Since it's being a tendency among paravirt clocksources to use values
> around 400, we should declare tsc as even better: So we use 500.
> 
> This patch also touches the comments on clocksource.h, which suggests
> that 499 would be a limit on the rating values.
> 
> Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>

Are you sure these paravirt sources don't intentionally trump the TSC?

	-hpa

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