From owner-cvs-all@FreeBSD.ORG Tue Feb 1 15:29:14 2005 Return-Path: Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 33E7916A4CF; Tue, 1 Feb 2005 15:29:14 +0000 (GMT) Received: from srv1.cosmo-project.de (srv1.cosmo-project.de [213.83.6.106]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1109043D6D; Tue, 1 Feb 2005 15:29:13 +0000 (GMT) (envelope-from ticso@cicely12.cicely.de) Received: from cicely5.cicely.de (cicely5.cicely.de [10.1.1.7]) (authenticated bits=0)j11FT6wh023724 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=OK); Tue, 1 Feb 2005 16:29:10 +0100 (CET) (envelope-from ticso@cicely12.cicely.de) Received: from cicely12.cicely.de (cicely12.cicely.de [IPv6:3ffe:400:8d0:301::12]) by cicely5.cicely.de (8.12.10/8.12.10) with ESMTP id j11FS5U3012093 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 1 Feb 2005 16:28:06 +0100 (CET) (envelope-from ticso@cicely12.cicely.de) Received: from cicely12.cicely.de (localhost [127.0.0.1]) by cicely12.cicely.de (8.12.11/8.12.11) with ESMTP id j11FS4OS032692; Tue, 1 Feb 2005 16:28:04 +0100 (CET) (envelope-from ticso@cicely12.cicely.de) Received: (from ticso@localhost) by cicely12.cicely.de (8.12.11/8.12.11/Submit) id j11FS4YR032691; Tue, 1 Feb 2005 16:28:04 +0100 (CET) (envelope-from ticso) Date: Tue, 1 Feb 2005 16:28:04 +0100 From: Bernd Walter To: John Baldwin Message-ID: <20050201152803.GC31822@cicely12.cicely.de> References: <200501312307.j0VN7gxm080740@repoman.freebsd.org> <200502010649.33768.jhb@FreeBSD.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200502010649.33768.jhb@FreeBSD.org> X-Operating-System: FreeBSD cicely12.cicely.de 5.2-CURRENT alpha User-Agent: Mutt/1.5.6i X-Spam-Status: No, hits=-4.9 required=3.0 tests=BAYES_00 autolearn=ham version=2.64 X-Spam-Report: * -4.9 BAYES_00 BODY: Bayesian spam probability is 0 to 1% * [score: 0.0000] X-Spam-Checker-Version: SpamAssassin 2.64 (2004-01-11) on cicely12.cicely.de cc: cvs-src@FreeBSD.org cc: Bernd Walter cc: src-committers@FreeBSD.org cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/alpha/alpha machdep.c src/sys/alpha/include cpuconf.h src/sys/alpha/pci lca.c lcareg.h X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: ticso@cicely.de List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 01 Feb 2005 15:29:14 -0000 On Tue, Feb 01, 2005 at 06:49:33AM -0500, John Baldwin wrote: > On Monday 31 January 2005 06:07 pm, Bernd Walter wrote: > > ticso 2005-01-31 23:07:42 UTC > > > > FreeBSD src repository > > > > Modified files: > > sys/alpha/alpha machdep.c > > sys/alpha/include cpuconf.h > > sys/alpha/pci lca.c lcareg.h > > Log: > > add cpu_idle support for 21066A based lca systems > > > > Revision Changes Path > > 1.229 +9 -1 src/sys/alpha/alpha/machdep.c > > 1.14 +1 -0 src/sys/alpha/include/cpuconf.h > > 1.21 +29 -0 src/sys/alpha/pci/lca.c > > 1.4 +2 -0 src/sys/alpha/pci/lcareg.h > > What exactly are the writes to this register doing btw? Also, is there any > reason we shouldn't just be using the PAL call that waits for the next > interrupt instead? It reduces clock speed until the next interrupt on 21066A CPUs and is a nop on plain 21066 CPUs. Would the PAL call work for SMP systems? AFAIK no alpha CPU has native halt support so there is not much magic that PAL can do for us. What I've found out about this case is that alpha CPUs automaticaly reduce power on unused parts and running just a tight loop, that works without memory access, for a few microsecsonds might be more efficient do do it ourself than calling PAL, which must be doing something similar. At least I think it is possible to reduce idle power consumption from the current situation either way. -- B.Walter BWCT http://www.bwct.de bernd@bwct.de info@bwct.de