From owner-freebsd-current@FreeBSD.ORG Fri Aug 15 23:57:01 2003 Return-Path: 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 C325B37B401 for ; Fri, 15 Aug 2003 23:57:01 -0700 (PDT) Received: from stork.mail.pas.earthlink.net (stork.mail.pas.earthlink.net [207.217.120.188]) by mx1.FreeBSD.org (Postfix) with ESMTP id 2A5C143FB1 for ; Fri, 15 Aug 2003 23:57:01 -0700 (PDT) (envelope-from tlambert2@mindspring.com) Received: from user-2ivflb5.dialup.mindspring.com ([165.247.213.101] helo=mindspring.com) by stork.mail.pas.earthlink.net with asmtp (SSLv3:RC4-MD5:128) (Exim 3.33 #1) id 19nuze-0003Wj-00; Fri, 15 Aug 2003 23:56:55 -0700 Message-ID: <3F3DD57F.5848FD64@mindspring.com> Date: Fri, 15 Aug 2003 23:55:59 -0700 From: Terry Lambert X-Mailer: Mozilla 4.79 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Thorsten Greiner References: <11229.1060970608@critter.freebsd.dk> <1060978640.603.11.camel@localhost> <20030815205047.GA719@tybalt> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-ELNK-Trace: b1a02af9316fbb217a47c185c03b154d40683398e744b8a4dec075ab57d3ce0dded3fb48c7c5959393caf27dac41a8fd350badd9bab72f9c350badd9bab72f9c cc: Poul-Henning Kamp cc: freebsd-current@FreeBSD.org cc: MATOBA Hirozumi cc: nate@root.org Subject: Re: clock works slowly when I change CPU speed X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 16 Aug 2003 06:57:02 -0000 Thorsten Greiner wrote: > * Bob Fleck [2003-08-15 22:46]: > > So, what should be done to restore the proper behavior of the > > timekeeping on these systems? > > $ dmesg | grep counter > Timecounter "i8254" frequency 1193182 Hz > Timecounter "ACPI-fast" frequency 3579545 Hz > Timecounter "TSC" frequency 1595302164 Hz > $ sysctl -w kern.timecounter.hardware=i8254 > > Fixes the problem for me. I suspect you should set this in > /etc/sysctl.conf to enable it permanently. I suspect that systems where ACPI indicates that the clock speed may change as a result of power management events should set this automatically so people don't have to hack up their system with sysctl's just to get things to work, when it's well known that the system selecting TSC by default on systems with a variable processor speed will experience problems otherwise. I'm guessing what changes in the patches is that the default for preferred clock changed to the wrong thing. -- Terry