From mboxrd@z Thu Jan  1 00:00:00 1970
From: Nivedita Singhvi <niv@us.ibm.com>
Subject: Re: [PATCH] per-cpu timer changes
Date: Thu, 26 May 2005 11:03:52 -0700
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	<20050526173457.GA4725@us.ibm.com>
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To: Don Fry <brazilnut@us.ibm.com>
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Don Fry wrote:

> The time going backwards was only occasionally, and it was a BIG jump
> backwards.  I tracked it down yesterday to a problem with doing 32-bit
> arithmetic in Linux on the tsc values.  For some reason, every 5-20
> minutes xen seems to pause for about 5 seconds.  This causes the tsc to
> wrap if only 32-bits are used, and the 'time went backwards' message is

What happens when there is activity on the system? Do you
still see the pause? 5 seconds is an inordinately long time,
and will impact networking if it happens during normal
workloads too..

thanks,
Nivedita