Message-ID: <4BCC829A.6000803@goop.org>
Date: Mon, 19 Apr 2010 09:19:38 -0700
From: Jeremy Fitzhardinge <jeremy@goop.org>
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To: Glauber Costa <glommer@redhat.com>
CC: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, avi@redhat.com,
       Marcelo Tosatti <mtosatti@redhat.com>,
       Zachary Amsden <zamsden@redhat.com>
Subject: Re: [PATCH 1/5] Add a global synchronization point for pvclock
References: <1271356648-5108-1-git-send-email-glommer@redhat.com> <1271356648-5108-2-git-send-email-glommer@redhat.com> <4BC8CA52.4090703@goop.org> <20100419142624.GE14158@mothafucka.localdomain>
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On 04/19/2010 07:26 AM, Glauber Costa wrote:
>> Is the problem that the tscs are starting out of sync, or that they're
>> drifting relative to each other over time?  Do the problems become worse
>> the longer the uptime?  How large are the offsets we're talking about here?
>>     
> The offsets usually seem pretty small, under a microsecond. So I don't think
> it has anything to do with tscs starting out of sync. Specially because the
> delta-based calculation has the exact purpose of handling that case.
>   

So you think they're drifting out of sync from an initially synced
state?  If so, what would bound the drift?

    J
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