From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bernhard Schmidt <berni@birkenwald.de>
Subject: Re: Clock jumps
Date: Fri, 28 May 2010 00:12:10 +0200
Message-ID: <4BFEEE3A.1010403@birkenwald.de>
References: <loom.20100524T171038-56@post.gmane.org> <20100525062100.GP22163@redhat.com> <4BFD5616.6070302@cora.nwra.com> <4D7E210A-4694-4B6E-B721-6024CE96ABC0@suse.de> <htmdsk$9kn$1@dough.gmane.org> <4BFEE9F3.8040200@redhat.com>
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Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org
To: Zachary Amsden <zamsden@redhat.com>
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On 27.05.2010 23:53, Zachary Amsden wrote:

Hello Zachary,

> I have server side fixes for this kvm-clock which seem to give me a
> stable clock on this machine, but for true SMP stability, you will need
> Glauber's guest side changes to kvmclock as well. It is impossible to
> guarantee strictly monotonic clocksource across multiple CPUs when
> frequency is dynamically changing (and also because of the C1E idle
> problems).

Is all this relevant only when the host is on TSC? Because I have seen 
these jumps when the host was on HPET and the guests were using kvm-clock.

Anyway, can you send me both patches? I'd like to try it, but I have 
completely lost track where the up-to-date patches are.

Bernhard