From owner-freebsd-stable@FreeBSD.ORG Sat Dec 22 15:59:29 2007 Return-Path: Delivered-To: stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id EE97616A468 for ; Sat, 22 Dec 2007 15:59:29 +0000 (UTC) (envelope-from smithi@nimnet.asn.au) Received: from gaia.nimnet.asn.au (nimbin.lnk.telstra.net [139.130.45.143]) by mx1.freebsd.org (Postfix) with ESMTP id 82D3213C4CC for ; Sat, 22 Dec 2007 15:59:27 +0000 (UTC) (envelope-from smithi@nimnet.asn.au) Received: from localhost (smithi@localhost) by gaia.nimnet.asn.au (8.8.8/8.8.8R1.5) with SMTP id CAA14515; Sun, 23 Dec 2007 02:59:08 +1100 (EST) (envelope-from smithi@nimnet.asn.au) Date: Sun, 23 Dec 2007 02:59:08 +1100 (EST) From: Ian Smith To: Claus Guttesen In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: stable@freebsd.org, User Ota Subject: Re: SMP on FreeBSD 6.x and 7.0: Worth doing? freenx@deweyonline.com X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 22 Dec 2007 15:59:30 -0000 On Sat, 22 Dec 2007, Claus Guttesen wrote: > > > I have noticed an entry in GENERIC called > > > > > > device cpufreq > > > > > > Could this have any influence on the performance (on FreeBSD)? > > > > > > I saw this device late in the 7.0 release-process and I since I'm > > > accustomed to comment out any devices and options I don't need I have > > > commented this out as well. So I haven't performed any tests with and > > > without this device. > > > > > > > Cpufreq is for CPU frequency scaling. In the linux world, the cpufreq > > daemon allows you to control your cpu speed and voltage using power > > profiles and such, which makes it a definite power saving tool for > > laptops. The cpufreq driver is already included with the Linux kernel, > > so I'm going to assume that they've just implemented the cpufreq driver > > in the kernel recently :) > > > > If enabled, it probably would have an impact on performance, however I > > have lost the ability to test such a function since my laptop decides > > not to POST anymore. > > Yes, I did figure out what the purpose of this device was. :-) My > point was that this could lead to lower benchmarks on servers if > GENERIC is used. http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/i386/conf/GENERIC ======================= Revision 1.473: download - view: text, markup, annotated - select for diffs Sun Jul 1 21:47:45 2007 UTC (5 months, 3 weeks ago) by njl Branches: MAIN Diff to: previous 1.472: preferred, colored Changes since revision 1.472: +3 -0 lines Add cpufreq(4) to GENERIC. It does not change the frequency by default, so systems should be relatively unaffected. Users can then simply enable powerd(8) in rc.conf to take advantage of it. Approved by: re ======================= FWIW, both my 5.5-STABLE APM laptop and 6.1-RELEASE GENERIC ACPI laptop show cpu/cpufreq in kernel (kldstat -v) so it's been there a long while. cheers, Ian