From owner-freebsd-current@FreeBSD.ORG  Fri Oct 28 20:12:10 2005
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
X-Original-To: current@freebsd.org
Delivered-To: freebsd-current@FreeBSD.ORG
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 57C2116A41F
	for <current@freebsd.org>; Fri, 28 Oct 2005 20:12:10 +0000 (GMT)
	(envelope-from cswiger@mac.com)
Received: from pi.codefab.com (pi.codefab.com [199.103.21.227])
	by mx1.FreeBSD.org (Postfix) with ESMTP id E800343D48
	for <current@freebsd.org>; Fri, 28 Oct 2005 20:12:09 +0000 (GMT)
	(envelope-from cswiger@mac.com)
Received: from localhost (localhost [127.0.0.1])
	by pi.codefab.com (Postfix) with ESMTP id 273895DAC;
	Fri, 28 Oct 2005 16:12:09 -0400 (EDT)
Received: from pi.codefab.com ([127.0.0.1])
	by localhost (pi.codefab.com [127.0.0.1]) (amavisd-new, port 10024)
	with ESMTP id 90651-07; Fri, 28 Oct 2005 16:12:08 -0400 (EDT)
Received: from [192.168.1.3] (pool-68-161-122-227.ny325.east.verizon.net
	[68.161.122.227])
	(using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits))
	(No client certificate requested)
	by pi.codefab.com (Postfix) with ESMTP id 14EEE5C46;
	Fri, 28 Oct 2005 16:12:08 -0400 (EDT)
Message-ID: <43628618.6080004@mac.com>
Date: Fri, 28 Oct 2005 16:12:08 -0400
From: Chuck Swiger <cswiger@mac.com>
Organization: The Courts of Chaos
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US;
	rv:1.7.12) Gecko/20050915
X-Accept-Language: en-us, en
MIME-Version: 1.0
To: John-Mark Gurney <gurney_j@resnet.uoregon.edu>
References: <4361F057.4030904@pp.nic.fi> <30622.1130493370@critter.freebsd.dk>
	<20051028200007.GP4115@funkthat.com>
In-Reply-To: <20051028200007.GP4115@funkthat.com>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: amavisd-new at codefab.com
Cc: Poul-Henning Kamp <phk@phk.freebsd.dk>, current@freebsd.org
Subject: Re: Timers and timing, was: MySQL Performance 6.0rc1
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>, 
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 28 Oct 2005 20:12:10 -0000

John-Mark Gurney wrote:
> Poul-Henning Kamp wrote this message on Fri, Oct 28, 2005 at 11:56 +0200:
[ ... ]
>               time(): 0.65022
>       gettimeofday(): 0.60886
> hydrogen,ttypa,/tmp,503#sysctl kern.timecounter.hardware=ACPI-fast
> kern.timecounter.hardware: TSC -> ACPI-fast
[ ... ]
>               time(): 1.33242
>       gettimeofday(): 1.33421
> 
> I was quite impressed by the speed up using the TSC over ACPI-fast...

Yes, but the frightening code in sys/i386/isa/clock.c suggests that the TSC and 
SMP do not play nice together, and neither does power-management stuff.

-- 
-Chuck