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Date: Fri, 28 Jul 2006 14:47:01 +0100
From: Brian Candler <B.Candler@pobox.com>
To: John Baldwin <jhb@freebsd.org>
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Cc: freebsd-current@freebsd.org, Oliver Fromme <olli@lurza.secnetix.de>
Subject: Re: vmstat's entries type
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On Fri, Jul 28, 2006 at 09:28:36AM -0400, John Baldwin wrote:
> 	lock incl counter
> 	jnc 1f
> 	lock incl counter+4
> 1:

That looks safe to me. How expensive is a forward jump like that, i.e. do
you get a pipeline bubble?

The 'polling' argument says just do

    lock incl counter

and poll all counters every 5 minutes, looking for a wrap. I think that's
almost certainly going to be cheaper, as long as you can keep track of where
all these counters are located.

Regards,

Brian.