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From: Keir Fraser <keir.fraser@eu.citrix.com>
To: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>,
	Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>
Subject: Re: xen tsc problems?
Date: Tue, 13 Jul 2010 18:48:19 +0100	[thread overview]
Message-ID: <C8626573.1A92C%keir.fraser@eu.citrix.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1007131647300.21432@kaball-desktop>

On 13/07/2010 18:39, "Stefano Stabellini" <Stefano.Stabellini@eu.citrix.com>
wrote:

> I started to wonder why the guest is seeing such a big tsc warp when xen
> is seeing 0, so I added more tracing and eventually I found out that the
> value of v->arch.hvm_vcpu.stime_offset is significantly different
> between the two vcpus and the difference increases after the scaling.
> Then I added timer_mode=1 to my vm config file and the problem went
> away.
> I think that delay_for_missed_ticks shouldn't cause tsc scew in
> the guest.

Well, timer_mode=1 is the default and I doubt in all seriousness that the
other modes get any use or testing.

 -- Keir

  reply	other threads:[~2010-07-13 17:48 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-07-13 14:37 xen tsc problems? Stefano Stabellini
2010-07-13 14:43 ` Keir Fraser
2010-07-13 15:37   ` Dan Magenheimer
2010-07-13 17:39     ` Stefano Stabellini
2010-07-13 17:48       ` Keir Fraser [this message]
2010-07-13 18:06         ` Dan Magenheimer
2010-07-13 18:14           ` Stefano Stabellini
2010-07-13 18:59             ` Keir Fraser
2010-07-13 19:32               ` Dan Magenheimer
2010-07-13 18:12         ` Keir Fraser

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