Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753534AbZA0IF3 (ORCPT ); Tue, 27 Jan 2009 03:05:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752152AbZA0IFU (ORCPT ); Tue, 27 Jan 2009 03:05:20 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:49002 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752138AbZA0IFT (ORCPT ); Tue, 27 Jan 2009 03:05:19 -0500 Date: Tue, 27 Jan 2009 08:59:12 +0100 From: Ingo Molnar To: Jeremy Fitzhardinge Cc: Zachary Amsden , Nick Piggin , Linux Kernel Mailing List , Linus Torvalds , "hpa@zytor.com" , "jeremy@xensource.com" , "chrisw@sous-sol.org" , "rusty@rustcorp.com.au" , Andrew Morton , Xen-devel Subject: Re: lmbench lat_mmap slowdown with CONFIG_PARAVIRT Message-ID: <20090127075912.GA6551@elte.hu> References: <20090120112634.GA20858@elte.hu> <20090120140324.GA26424@elte.hu> <49763806.5090009@goop.org> <20090120205653.GA19710@elte.hu> <20090121072718.GN24891@wotan.suse.de> <4977A051.8050203@goop.org> <1232663311.16317.176.camel@bodhitayantram.eng.vmware.com> <4978F6C6.3090003@goop.org> <1232664907.16317.182.camel@bodhitayantram.eng.vmware.com> <49790BCC.1040807@goop.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49790BCC.1040807@goop.org> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 930 Lines: 27 * Jeremy Fitzhardinge wrote: >>> Also, I just posted patches to get rid of all pvops calls when >>> fetching or setting flags in a pte, which I hope will help. >> >> Sounds like it will help. > > ...but apparently not. ping? This is a very serious paravirt_ops slowdown affecting the native kernel's performance to the tune of 5-10% in certain workloads. It's been about 2 years ago that paravirt_ops went upstream, when you told us that something like this would never happen, that paravirt_ops is designed so flexibly that it will never hinder the native kernel - and if it does it will be easy to fix it. Now is the time to fulfill that promise. 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/