Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752275AbXBFSQo (ORCPT ); Tue, 6 Feb 2007 13:16:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752270AbXBFSQn (ORCPT ); Tue, 6 Feb 2007 13:16:43 -0500 Received: from colin.muc.de ([193.149.48.1]:4266 "EHLO mail.muc.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751258AbXBFSQn (ORCPT ); Tue, 6 Feb 2007 13:16:43 -0500 Date: 6 Feb 2007 19:16:41 +0100 Date: Tue, 6 Feb 2007 19:16:41 +0100 From: Andi Kleen To: Arjan van de Ven Cc: Rusty Russell , Zachary Amsden , Linux Kernel Mailing List , Andrew Morton , Jeremy Fitzhardinge , Chris Wright Subject: Re: [PATCH 0/11] VMI / Paravirt bugfixes for 2.6.21 Message-ID: <20070206181641.GA35903@muc.de> References: <200702060352.l163q87K000713@zach-dev.vmware.com> <1170736029.29293.31.camel@localhost.localdomain> <45C809F9.2090905@vmware.com> <1170738676.29293.35.camel@localhost.localdomain> <1170752856.7324.5.camel@laptopd505.fenrus.org> <20070206122514.GA47229@muc.de> <1170765952.7324.15.camel@laptopd505.fenrus.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1170765952.7324.15.camel@laptopd505.fenrus.org> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1370 Lines: 35 On Tue, Feb 06, 2007 at 01:45:52PM +0100, Arjan van de Ven wrote: > On Tue, 2007-02-06 at 13:25 +0100, Andi Kleen wrote: > > > hmm stolen time could even be useful without virtualization; to a large > > > degree, if cpufreq reduces the speed of your cpu you have "stolen > > > cycles" that way... I wonder if this concept can be used for that as > > > well... > > > > > I don't see the point, frankly. > > I mean for showing the sysadmin that his system has spare capacity left. > > right now top shows 50% in use (at say 600Mhz) while the 2.8Ghz > processor obviously isn't even nearly half loaded. Not necessarily. You have no guarantee that it will go much faster at full frequency. e.g. if the workload is memory bound then core frequency won't affect it much. Also if you're using automatic frequency scaling (which probably the far majority of users do) then if anything keeps the system busy for some time it will scale up anyways. This means even at 50% load you will be likely running at full speed already. I suspect there will be that many variables that automatic adjustment is probably not useful. -Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/