Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758114AbZDPQ6Q (ORCPT ); Thu, 16 Apr 2009 12:58:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756058AbZDPQ57 (ORCPT ); Thu, 16 Apr 2009 12:57:59 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:44502 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756035AbZDPQ56 (ORCPT ); Thu, 16 Apr 2009 12:57:58 -0400 Date: Thu, 16 Apr 2009 18:56:40 +0200 From: Ingo Molnar To: Linus Torvalds Cc: Jesse Barnes , Yinghai Lu , Andrew Morton , Thomas Gleixner , "H. Peter Anvin" , "linux-kernel@vger.kernel.org" , linux-pci@vger.kernel.org, yannick.roehlly@free.fr Subject: Re: [PATCH] x86/pci: make pci_mem_start to be aligned only -v3 Message-ID: <20090416165640.GA13927@elte.hu> References: <200904101913.n3AJDhMm018684@demeter.kernel.org> <49DFABCC.3070001@kernel.org> <49E00E9F.8030605@kernel.org> <49E4F6D6.6030709@kernel.org> <49E4F71F.10107@kernel.org> <49E52A7A.4070607@kernel.org> <49E52D3F.1090206@kernel.org> <20090416093152.6605612d@hobbes> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1541 Lines: 40 * Linus Torvalds wrote: > On Thu, 16 Apr 2009, Jesse Barnes wrote: > > > > Any comments on this one, Linus? Should I include your ack? > > I'm not ready to ack it, no. I don't think the suggested patch is very > clean or necessarily sensible as-is. It seems very ad-hoc. > > I was literally thinking of something like > "round up from the last RAM by X" > "round up from the last reserved region by Y" > "pick the bigger of the two" > > with helper functions for the two cases and comments along the > lines of why we do it. Something that was a bit more obvious about > what it's doing and why. That's sensible - but i'd also like to inject hpa's add-on idea: if we do that then we should do it _explicitly_ and _visibly_, by injecting an artificial e820 reservation range to all expected "vulnerable" holes we cannot fully trust. We'd do that after all the fixed resources are allocated, but before dynamic PCI allocations. That prevents the PCI layer from dynamically allocating anything into that protective zone, and documents it as well (and makes it visible in boot logs, etc.) - instead of just a silent rule somewhere that no-one will really see if it breaks. Or would this be a bad idea for some obvious reason i missed? Ingo -- 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/