linux-kernel - Re: AMD X2 unsynced TSC fix?

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Date:	Fri, 27 Oct 2006 18:08:22 -0400
From:	Lee Revell <rlrevell@...-job.com>
To:	Chris Friesen <cfriesen@...tel.com>
Cc:	Andi Kleen <ak@...e.de>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	john stultz <johnstul@...ibm.com>
Subject: Re: AMD X2 unsynced TSC fix?

On Fri, 2006-10-27 at 15:48 -0600, Chris Friesen wrote:
> Lee Revell wrote:
> 
> > What exactly does that AMD patch do?
> 
> "...by periodically adjusting the core time-stamp-counters, so that they 
> are synchronized."
> 
> It sounds like they just periodically write a new value to the TSC. 
> Presumably they set the "slower" one equal to the "faster" one.
> 
> You'd likely still have windows where time might run backwards, but it 
> would be better than nothing.

The patch also apparently changes boot params to make the OS use the
ACPI PM timer, so it must not be a complete solution.

Lee

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