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Re: [Xen-devel] [PATCH] per-cpu timer changes

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..


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