From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161621AbXDYG5T (ORCPT ); Wed, 25 Apr 2007 02:57:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161625AbXDYG5T (ORCPT ); Wed, 25 Apr 2007 02:57:19 -0400 Received: from ns1.suse.de ([195.135.220.2]:39102 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161621AbXDYG5S (ORCPT ); Wed, 25 Apr 2007 02:57:18 -0400 From: Andi Kleen Organization: SUSE Linux Products GmbH, Nuernberg, GF: Markus Rex, HRB 16746 (AG Nuernberg) To: "H. Peter Anvin" Subject: Re: [Intel IOMMU][patch 8/8] Preserve some Virtual Address when devices cannot address entire range. Date: Wed, 25 Apr 2007 08:55:48 +0200 User-Agent: KMail/1.9.6 Cc: David Miller , ashok.raj@intel.com, linux-kernel@vger.kernel.org, akpm@osdl.org, gregkh@suse.de, muli@il.ibm.com, asit.k.mallick@intel.com, suresh.b.siddha@intel.com, anil.s.keshavamurthy@intel.com, arjan@linux.intel.com, shaohua.li@intel.com References: <200704242312.54738.ak@suse.de> <200704250003.57968.ak@suse.de> <462EAB13.4040104@zytor.com> In-Reply-To: <462EAB13.4040104@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200704250855.49242.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 25 April 2007 03:12:51 H. Peter Anvin wrote: > You can probably find almost any possible bitmask if you look long > enough. Hardware vendors are notorious for this kind of "optimizations". The nice thing is if this was solved in the IOMMU code then we could drop (or not initialize) GFP_DMA on systems with that hardware. I guess GFP_DMA32 would still need to stay for the graphics devices though. Not sure how much difference it would make though, but at least Christoph Lameter seems to think it would. -Andi