Subject: Re: [PATCH 0/3] Improve TSC as a clocksource under VMware
From: Alok Kataria <akataria@vmware.com>
Reply-To: akataria@vmware.com
To: Andi Kleen <andi@firstfloor.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>, LKML <linux-kernel@vger.kernel.org>,
       the arch/x86 maintainers <x86@kernel.org>,
       Daniel Hecht <dhecht@vmware.com>
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Content-Type: text/plain
Organization: VMware INC.
Date: Tue, 21 Oct 2008 14:41:56 -0700
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On Tue, 2008-10-21 at 12:47 -0700, Alok Kataria wrote:
> On Tue, 2008-10-21 at 12:27 -0700, Andi Kleen wrote:
> > On Tue, Oct 21, 2008 at 12:10:36PM -0700, Alok Kataria wrote:
> > > On Tue, 2008-10-21 at 11:15 -0700, Andi Kleen wrote:

> > When the margin changes then it likely won't be good enough for
> > gettimeofday(). There are a couple of testers for monotonity around,
> > would such a system with shifting marging surive running them
> > for a few days?
> 
> I meant, the margin changes when you are running different flavors of
> the build, or running different user configurations (from overcommitment
> POV). Once a system is booted the margin won't vary, apart from the
> bootup stage which will always have some extreme states. In all our
> internal testing that has been done, 

> we have never noticed time drift is
> withing the NTP threshold when its compared to the host system, under
> varying load. 
> 

oops... i meant the time drift is _always_ within the NTP threshold.


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