Re: xen 2: bogus microtime value

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Sat, Apr 28, 2007 at 06:53:20PM +0900, fukumoto%imasy.or.jp@localhost wrote:
> I'm trying to setup xen 2, but having problem.  One problem filed as
> kern/36188.  To track the problem, I tried ktrace/kdump, and I noticed
> the timestamp of kdump -T is bogus.  I looked into the
> sys/arch/xen/xen/clock.c, and apparently some offset attempt seems to
> be made when XEN_CLOCK_DEBUG is turned on.  When I recompiled
> XEN2_DOM0 with XEN_CLOCK_DEBUG, dmesg is filled with "xen_microtime:
> unexpectedly large tv_usec 6445854" and so on.
> 
> So, is this something expected, or bug?  Kernel is netbsd-4, xenkernel
> is xen-2.0.7 from pkgsrc.

I don't remember the details exatly (I think they are in port-xen archives),
but I think the xen-2 hypervisor interface doesn't allow for precise
microtime support. Xen-3 is better in this area.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--