From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758554AbXFZPL4 (ORCPT ); Tue, 26 Jun 2007 11:11:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757447AbXFZPLe (ORCPT ); Tue, 26 Jun 2007 11:11:34 -0400 Received: from mtagate8.uk.ibm.com ([195.212.29.141]:46981 "EHLO mtagate8.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756725AbXFZPLb (ORCPT ); Tue, 26 Jun 2007 11:11:31 -0400 Date: Tue, 26 Jun 2007 11:11:25 -0400 From: Muli Ben-Yehuda To: Arjan van de Ven Cc: Andi Kleen , Andrew Morton , "Keshavamurthy, Anil S" , linux-kernel@vger.kernel.org, gregkh@suse.de, suresh.b.siddha@intel.com, ashok.raj@intel.com, davem@davemloft.net, clameter@sgi.com Subject: Re: [Intel IOMMU 00/10] Intel IOMMU support, take #2 Message-ID: <20070626151125.GD8274@rhun.ibm.com> References: <20070619213701.219910000@askeshav-devel.jf.intel.com> <20070625234550.058635cb.akpm@linux-foundation.org> <200706260912.45838.ak@suse.de> <20070626111324.GB4320@rhun.ibm.com> <46812ADF.3060609@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46812ADF.3060609@linux.intel.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 26, 2007 at 08:03:59AM -0700, Arjan van de Ven wrote: > Muli Ben-Yehuda wrote: > >How much? we have numbers (to be presented at OLS later this week) > >that show that on bare-metal an IOMMU can cost as much as 15%-30% more > >CPU utilization for an IO intensive workload (netperf). It will be > >interesting to see comparable numbers for VT-d. > > for VT-d it is a LOT less. I'll let anil give you his data :) Looking forward to it. Note that this is on a large SMP machine with Gigabit ethernet, with netperf TCP stream. Comparing numbers for other benchmarks on other machines is ... less than useful, but the numbers themeselves are interesting. Cheers, Muli