From owner-freebsd-stable@FreeBSD.ORG  Sat Nov 29 16:02:50 2003
Return-Path: <owner-freebsd-stable@FreeBSD.ORG>
Delivered-To: freebsd-stable@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id 1E1BA16A4CE; Sat, 29 Nov 2003 16:02:50 -0800 (PST)
Received: from critter.freebsd.dk (critter.freebsd.dk [212.242.86.163])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id 56C9A43FAF; Sat, 29 Nov 2003 16:02:48 -0800 (PST)
	(envelope-from phk@phk.freebsd.dk)
Received: from critter.freebsd.dk (localhost [127.0.0.1])
	by critter.freebsd.dk (8.12.10/8.12.10) with ESMTP id hAU02lgS021273;
	Sun, 30 Nov 2003 01:02:47 +0100 (CET)
	(envelope-from phk@phk.freebsd.dk)
To: "Marc G. Fournier" <scrappy@hub.org>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Sat, 29 Nov 2003 19:30:18 -0400."
             <20031129192903.U99096@ganymede.hub.org> 
Date: Sun, 30 Nov 2003 01:02:47 +0100
Message-ID: <21272.1070150567@critter.freebsd.dk>
cc: stable@FreeBSD.org
cc: current@FreeBSD.org
cc: 'Kris Kennaway' <kris@obsecurity.org>
Subject: Re: Corrected gettimeofday() test code 
X-BeenThere: freebsd-stable@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Production branch of FreeBSD source code
	<freebsd-stable.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>,
	<mailto:freebsd-stable-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-stable>
List-Post: <mailto:freebsd-stable@freebsd.org>
List-Help: <mailto:freebsd-stable-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>,
	<mailto:freebsd-stable-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 30 Nov 2003 00:02:50 -0000

In message <20031129192903.U99096@ganymede.hub.org>, "Marc G. Fournier" writes:
>On Sat, 29 Nov 2003, Don Bowman wrote:
>
>> For this config (below), kern.timecounter.method=0 reproduces the
>> problem, kern.timecounter.method=1 does not.
>
>Can anyone comment on what effect setting method to 1 has on the system?
>Like, would one notice a degradation in performance?

Setting it to 1 forces the timecounter to update every HZ.

You can say that 0 was an optimization which it seems may not be
safe on certain hardware combinations...

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.