Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932193AbXBWKah (ORCPT ); Fri, 23 Feb 2007 05:30:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932197AbXBWKah (ORCPT ); Fri, 23 Feb 2007 05:30:37 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:57391 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932193AbXBWKag (ORCPT ); Fri, 23 Feb 2007 05:30:36 -0500 Date: Fri, 23 Feb 2007 11:22:53 +0100 From: Ingo Molnar To: "Michael K. Edwards" Cc: Alan , Evgeniy Polyakov , Ulrich Drepper , linux-kernel@vger.kernel.org, Linus Torvalds , Arjan van de Ven , Christoph Hellwig , Andrew Morton , Zach Brown , "David S. Miller" , Suparna Bhattacharya , Davide Libenzi , Jens Axboe , Thomas Gleixner Subject: Re: [patch 00/13] Syslets, "Threadlets", generic AIO support, v3 Message-ID: <20070223102253.GA22870@elte.hu> References: <20070221211355.GA7302@elte.hu> <20070221233111.GB5895@elte.hu> <45DCD9E5.2010106@redhat.com> <20070222074044.GA4158@elte.hu> <20070222113148.GA3781@2ka.mipt.ru> <20070222125931.GB25788@elte.hu> <20070223003018.0d244576@lxorguk.ukuu.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.0.3 -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 998 Lines: 24 * Michael K. Edwards wrote: > On 2/22/07, Alan wrote: > > We don't use the FPU in the kernel except in very weird cases where > > it makes an enormous performance difference. The threadlets also > > have the same page tables so they have the same %cr3 so its very > > cheap to switch, basically a predicted jump and some register loads > > Do you not understand that real user code touches FPU state at > unpredictable (to the kernel) junctures? Maybe not in a database or a > web server, but in the GUIs and web-based monitoring applications that > are 99% of the potential customers for kernel AIO? > I have no idea what a %cr3 is, [...] then please stop wasting Alan's time ... Ingo - 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/