From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262381AbUBXSOi (ORCPT ); Tue, 24 Feb 2004 13:14:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262363AbUBXSOh (ORCPT ); Tue, 24 Feb 2004 13:14:37 -0500 Received: from mx1.redhat.com ([66.187.233.31]:22754 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S262381AbUBXSNp (ORCPT ); Tue, 24 Feb 2004 13:13:45 -0500 Date: Tue, 24 Feb 2004 10:13:40 -0800 From: "David S. Miller" To: Andi Kleen Cc: torvalds@osdl.org, linux-kernel@vger.kernel.org Subject: Re: IOMMUs was Re: Intel vs AMD x86-64 Message-Id: <20040224101340.47341f28.davem@redhat.com> In-Reply-To: References: <20040223134853.5947a414.davem@redhat.com.suse.lists.linux.kernel> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; sparc-unknown-linux-gnu) X-Face: "_;p5u5aPsO,_Vsx"^v-pEq09'CU4&Dc1$fQExov$62l60cgCc%FnIwD=.UF^a>?5'9Kn[;433QFVV9M..2eN.@4ZWPGbdi<=?[:T>y?SD(R*-3It"Vj:)"dP Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 24 Feb 2004 15:06:47 +0100 Andi Kleen wrote: > One side effect of this is that the IOMMU TLB flush strategy is a bit > dumb, because it has to do config space accesses for it. This can be costly, but if you flush the IOMMU like sparc64 does (basically it's similar to how KMAPs are flushed on x86), the cost gets real low because then you only flush the whole iommu once every time you walk the whole mapping table of the iommu. I'm sure you've probably thought of this already, just mentioning it in case you haven't.