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To: "Matthew D. Fuller" <fullermd@over-yonder.net>
In-reply-to: Your message of "Mon, 05 Dec 2005 13:47:56 CST."
	<20051205194756.GG90806@over-yonder.net> 
Date: Mon, 05 Dec 2005 12:43:19 -0800
From: "Kevin Oberman" <oberman@es.net>
Message-Id: <20051205204319.787065D04@ptavv.es.net>
Cc: kama <kama@pvp.se>, freebsd-stable@freebsd.org,
	Peter Jeremy <PeterJeremy@optushome.com.au>
Subject: Re: cpu-timer rate 
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> Date: Mon, 5 Dec 2005 13:47:56 -0600
> From: "Matthew D. Fuller" <fullermd@over-yonder.net>
> 
> On Mon, Dec 05, 2005 at 10:15:52AM -0800 I heard the voice of
> Kevin Oberman, and lo! it spake thus:
> > > From: "Matthew D. Fuller" <fullermd@over-yonder.net>
> > > 
> > > Because the rate is always twice hz.
> > 
> > While I will concede that I have no explanation, but on all of my
> > systems rate = HZ +/-1. I have never seen a case where rate/2 = HZ.
> 
> Well, OK, it always is when you're using the LAPIC timer, which I
> think is on 6.x and up (with the APIC enabled, of course).  When
> you're using irq0, it just runs at hz.

That would explain it. While most of the systems in question are V6 or
V7, none is multi-processor and, being conservative, I don't run APIC
on any of them. (An exception is my -current system, but it locks up on
boot with APIC enabled.)

Maybe I should try it some time just to see what happens. ;-)

Thanks.
-- 
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman@es.net			Phone: +1 510 486-8634