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From: Bernhard Schmidt <berni@birkenwald.de>
To: Zachary Amsden <zamsden@redhat.com>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: Clock jumps
Date: Fri, 28 May 2010 00:12:10 +0200	[thread overview]
Message-ID: <4BFEEE3A.1010403@birkenwald.de> (raw)
In-Reply-To: <4BFEE9F3.8040200@redhat.com>

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

  reply	other threads:[~2010-05-27 22:12 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <loom.20100524T171038-56@post.gmane.org>
2010-05-25  6:21 ` Clock jumps Gleb Natapov
2010-05-26 17:10   ` Orion Poplawski
2010-05-26 17:31     ` Alexander Graf
2010-05-26 17:50       ` Orion Poplawski
2010-05-26 22:55       ` Orion Poplawski
2010-05-27 18:32       ` Bernhard Schmidt
2010-05-27 19:08         ` john stultz
2010-05-27 21:48           ` Bernhard Schmidt
2010-05-28  0:00             ` john stultz
2010-05-28  0:33               ` Bernhard Schmidt
2010-05-28  0:46                 ` john stultz
2010-05-27 21:53         ` Zachary Amsden
2010-05-27 22:12           ` Bernhard Schmidt [this message]
2010-05-27 22:20             ` Zachary Amsden
2010-05-27 22:22             ` Zachary Amsden
2010-06-02 22:54       ` Orion Poplawski

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