[Xen-devel] Re: Bizarre pv kernel ultra-high frequency rdtsc?!?

To:	Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>, Jeremy Fitzhardinge <jeremy@xxxxxxxx>
Subject:	[Xen-devel] Re: Bizarre pv kernel ultra-high frequency rdtsc?!?
From:	Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date:	Sat, 21 Nov 2009 21:45:24 +0000
Cc:	"Xen-Devel \(E-mail\)" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date:	Sat, 21 Nov 2009 13:45:50 -0800
Envelope-to:	www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to:	<fae586af-0866-42b3-b309-4927042317c7@default>
List-help:	<mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id:	Xen developer discussion <xen-devel.lists.xensource.com>
List-post:	<mailto:xen-devel@lists.xensource.com>
List-subscribe:	<http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe:	<http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Sender:	xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index:	AcpqO5Lnv7L6gkH7SlW2z3wkyWp7hgAuFtXO
Thread-topic:	Bizarre pv kernel ultra-high frequency rdtsc?!?
User-agent:	Microsoft-Entourage/12.23.0.091001

On 20/11/2009 23:45, "Dan Magenheimer" <dan.magenheimer@xxxxxxxxxx> wrote:

> -        _u.tsc_timestamp     = t->stime_local_stamp;
> -        _u.system_time       = t->stime_local_stamp;
> +        _u.tsc_timestamp     = t->stime_local_stamp - BIG_OFFSET;
> +        _u.system_time       = t->stime_local_stamp - BIG_OFFSET;

Ah, the line above is the bug. You should be subtracting BIG_OFFSET from
_u.tsc_timestamp only. Leave _u.system_time as it is. That'll fix all your
observed problems.

 -- Keir

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

WARNING - OLD ARCHIVES

xen-devel

[Xen-devel] Re: Bizarre pv kernel ultra-high frequency rdtsc?!?