From owner-freebsd-acpi@FreeBSD.ORG Thu Apr 30 21:41:23 2009 Return-Path: Delivered-To: freebsd-acpi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id BFD82106567E; Thu, 30 Apr 2009 21:41:23 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id 902F38FC22; Thu, 30 Apr 2009 21:41:23 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from bigwig.baldwin.cx (66.111.2.69.static.nyinternet.net [66.111.2.69]) by cyrus.watson.org (Postfix) with ESMTPSA id 4507146B09; Thu, 30 Apr 2009 17:41:23 -0400 (EDT) Received: from jhbbsd.hudson-trading.com (unknown [209.249.190.8]) by bigwig.baldwin.cx (Postfix) with ESMTPA id 294918A023; Thu, 30 Apr 2009 17:41:22 -0400 (EDT) From: John Baldwin To: freebsd-acpi@freebsd.org Date: Thu, 30 Apr 2009 08:46:41 -0400 User-Agent: KMail/1.9.7 References: <200904270150.31912.pieter@degoeje.nl> <7d6fde3d0904261927s1a67cf85jc982c1a68e30e081@mail.gmail.com> In-Reply-To: <7d6fde3d0904261927s1a67cf85jc982c1a68e30e081@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200904300846.41576.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0.1 (bigwig.baldwin.cx); Thu, 30 Apr 2009 17:41:22 -0400 (EDT) X-Virus-Scanned: clamav-milter 0.95 at bigwig.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-0.6 required=4.2 tests=AWL,BAYES_00, DATE_IN_PAST_06_12,RDNS_NONE autolearn=no version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on bigwig.baldwin.cx Cc: acpi , freebsd-performance@freebsd.org, freebsd-hackers@freebsd.org, Pieter de Goeje Subject: Re: ACPI-fast default timecounter, but HPET 83% faster X-BeenThere: freebsd-acpi@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: ACPI and power management development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 30 Apr 2009 21:41:24 -0000 On Sunday 26 April 2009 10:27:42 pm Garrett Cooper wrote: > I'm seeing similar results. > > [root@orangebox /usr/home/gcooper]# dmesg | grep 'Timecounter "' > Timecounter "i8254" frequency 1193182 Hz quality 0 > Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000 > Timecounter "HPET" frequency 14318180 Hz quality 900 > [root@orangebox /usr/home/gcooper]# ./cgt > 1369355 > [root@orangebox /usr/home/gcooper]# sysctl > kern.timecounter.hardware="ACPI-fast" > kern.timecounter.hardware: HPET -> ACPI-fast > [root@orangebox /usr/home/gcooper]# ./cgt > 772289 > > Why's the default ACPI-fast? For power-saving functionality or because > of the `quality' factor? What is the criteria that determines the > `quality' of a clock as what's being reported above (I know what > determines the quality of a clock visually from a oscilloscope =])? I suspect that the quality of the HPET driver is lower simply because no one had measured it previously and HPET is newer and less "proven". -- John Baldwin