Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757469AbYHTO0q (ORCPT ); Wed, 20 Aug 2008 10:26:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753488AbYHTO0i (ORCPT ); Wed, 20 Aug 2008 10:26:38 -0400 Received: from smtpq2.groni1.gr.home.nl ([213.51.130.201]:43902 "EHLO smtpq2.groni1.gr.home.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753348AbYHTO0h (ORCPT ); Wed, 20 Aug 2008 10:26:37 -0400 Message-ID: <48AC29CA.1060203@keyaccess.nl> Date: Wed, 20 Aug 2008 16:27:22 +0200 From: Rene Herman User-Agent: Thunderbird 2.0.0.16 (X11/20080707) MIME-Version: 1.0 To: Ingo Molnar CC: Venki Pallipadi , Dave Airlie , "Li, Shaohua" , Yinghai Lu , Andreas Herrmann , Arjan van de Ven , "dri-users@lists.sourceforge.net" , Linux Kernel , "Siddha, Suresh B" , Thomas Gleixner , "H. Peter Anvin" , Dave Jones Subject: Re: AGP and PAT (induced?) problem (on AMD family 6) References: <48972EA8.8040001@keyaccess.nl> <20080815142218.GC12954@elte.hu> <48A59FAC.7050605@keyaccess.nl> <48AA9C3B.5030309@keyaccess.nl> <20080819102633.GE6722@elte.hu> <48AAD680.7020508@keyaccess.nl> <20080819190757.GA17470@linux-os.sc.intel.com> <20080820100440.GE28492@elte.hu> <48ABF6DC.8070305@keyaccess.nl> In-Reply-To: <48ABF6DC.8070305@keyaccess.nl> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Score: -1.0 (-) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2045 Lines: 47 On 20-08-08 12:50, Rene Herman wrote: > On 20-08-08 12:04, Ingo Molnar wrote: > >> * Venki Pallipadi wrote: >> >>>> I'd really like a reply from the AGP or PAT side right about now. >>> Hmm. Looks like there are more than 16000 entries in the PAT list! >> >> hm, btw., why is that? > > Because 64M of AGP memory divided by 4K pages is 16K. That is, the > underlying problem seems to be AGP drivers using order 0 allocations. > I'm looking. > > Do note also that this means that Venki's change would not constitite a > correct/final fix. Sure, caching the last entry speeds up traversing a > 16K entry list but the issue is that there shouldn't be a 16K entry > list. Through AGP, or maybe even by coalescing entries in the PAT list > if that's at all possible (I guess it's not really). > > Even if such a more fundamental fix isn't (easily) available, the PAT > code already comments that the list, which is sorted by ->start value, > is expected to be short, and should be turned into an rbtree if it isn't > which might be slightly less of a bandaid. > > Dave Airlie (as the MAINTAINERS entry) can't be arsed to answer email it > seems so I've added Dave Jones for a possible comment from the AGP side. > If I'm reading this right upto now, still many AGP driver (among which > my amd-k7-agp) are affected. This was based on a wrong reading; I was looking at the GATT allocation. I'm giving up looking until someone can tell me whether or not those 16K entries are expected though. I have just one AGP card in a PAT capable machine. How many entries in /debug/x86/pat_memtype_list are there on other AGP systems with Option "AGPSize" "64" in their xorg.conf:"Device" section (and their AGP aperture set to 64M or bigger in the BIOS)? Rene. -- 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/