Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751494AbZJWAM2 (ORCPT ); Thu, 22 Oct 2009 20:12:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751324AbZJWAM1 (ORCPT ); Thu, 22 Oct 2009 20:12:27 -0400 Received: from mga11.intel.com ([192.55.52.93]:5405 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751080AbZJWAM1 (ORCPT ); Thu, 22 Oct 2009 20:12:27 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.44,608,1249282800"; d="scan'208";a="506390646" Subject: Re: [RFC Patch] use MTRR for write combining if PAT is not available From: Suresh Siddha Reply-To: Suresh Siddha To: Jesse Barnes Cc: Eric Anholt , Thomas Schlichter , Ingo Molnar , Jan Beulich , Jeremy Fitzhardinge , Robert Hancock , Henrique de Moraes Holschuh , "Pallipadi, Venkatesh" , Tejun Heo , "x86@kernel.org" , Yinghai Lu , Thomas Gleixner , Arjan van de Ven , "dri-devel@lists.sourceforge.net" , Ingo Molnar , "linux-kernel@vger.kernel.org" , Thomas Hellstrom , "H. Peter Anvin" In-Reply-To: <20091023081047.4d8abc29@jbarnes-x200> References: <1394846127@web.de> <4ADF32A0020000780001B20A@vpn.id2.novell.com> <20091021173514.GA32227@elte.hu> <200910212201.36578.thomas.schlichter@web.de> <1256205210.2530.28.camel@sbs-t61> <1256225689.32075.6.camel@gaiman.anholt.net> <1256248050.2546.9.camel@sbs-t61> <20091023081047.4d8abc29@jbarnes-x200> Content-Type: text/plain Organization: Intel Corp Date: Thu, 22 Oct 2009 17:11:57 -0700 Message-Id: <1256256717.2534.6.camel@sbs-t61> Mime-Version: 1.0 X-Mailer: Evolution 2.26.3 (2.26.3-1.fc11) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 974 Lines: 24 On Thu, 2009-10-22 at 16:10 -0700, Jesse Barnes wrote: > On Thu, 22 Oct 2009 14:47:30 -0700 > Suresh Siddha wrote: > > > On Thu, 2009-10-22 at 08:34 -0700, Eric Anholt wrote: > > > Can we just not create the _wc sysfs entry if we don't have PAT? I > > > don't think there's userland relying on its presence as opposed to > > > the non-_wc entry. > > > > Yes indeed. Jesse do you see an issue with this? This is simple and > > clean. Thanks Eric. > > Yeah, I think that will be fine. In fact, older versions of > libpciaccess will behave better if we do it that way (iirc it only > allocates an MTRR if the resource_wc file doesn't exist or fails to get > mapped). Eric, care to send the patch? -- 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/