Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964869AbVLISpm (ORCPT ); Fri, 9 Dec 2005 13:45:42 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932515AbVLISpl (ORCPT ); Fri, 9 Dec 2005 13:45:41 -0500 Received: from mx1.redhat.com ([66.187.233.31]:51881 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S932513AbVLISpl (ORCPT ); Fri, 9 Dec 2005 13:45:41 -0500 Date: Fri, 9 Dec 2005 13:45:17 -0500 From: Dave Jones To: Daniel J Blueman Cc: tripperda@nvidia.com, Linux Kernel , ak@suse.de, jgarzik@pobox.com Subject: Re: PAT status? Message-ID: <20051209184517.GB7473@redhat.com> Mail-Followup-To: Dave Jones , Daniel J Blueman , tripperda@nvidia.com, Linux Kernel , ak@suse.de, jgarzik@pobox.com References: <6278d2220512080737t30a83011k11e88e85c0974a11@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6278d2220512080737t30a83011k11e88e85c0974a11@mail.gmail.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1416 Lines: 33 On Thu, Dec 08, 2005 at 03:37:43PM +0000, Daniel J Blueman wrote: > Terence Ripperda wrote: > > Hi Jeff, > > > > I unfortunately haven't had much time to look at the status of the PAT > > code I had been working on. there are really 2 steps to the code: > > > > the first is enabling and configuring the PAT registers. this then > > allows a page table entry define that can be passed to traditional > > interfaces, such as remap_page_range or change_page_attr. this is > > pretty simple and we've been using a similar interface in our driver > > for some time now. > > Presumably, the aliasing will only bite where eg the X server sets up > MTRRs and PAT is used for the region also. For x86_64 and IA32, the > Intel IA32 system guides tell us that strong store ordering (ie > write-through) takes precendence over weaker store ordering (eg > write-combining), so we should be safe. For processors with known > errata with PAT etc, we can disable PAT support. > > Would it be useful to get a rough patch covering point #1 onto LKML > for discussion? http://lwn.net/Articles/135883/ is Terrence's last patch rediffed against 2.6.12 patch. Dave - 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/