Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755526AbaFKN64 (ORCPT ); Wed, 11 Jun 2014 09:58:56 -0400 Received: from qmta10.emeryville.ca.mail.comcast.net ([76.96.30.17]:50022 "EHLO qmta10.emeryville.ca.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752172AbaFKN6y (ORCPT ); Wed, 11 Jun 2014 09:58:54 -0400 Date: Wed, 11 Jun 2014 08:58:51 -0500 (CDT) From: Christoph Lameter To: Luiz Capitulino cc: Yinghai Lu , Tejun Heo , Andrew Morton , Andi Kleen , Rik van Riel , Yasuaki Ishimatsu , Linux MM , Linux Kernel Mailing List , "stable@vger.kernel.org" Subject: Re: [PATCH] x86: numa: drop ZONE_ALIGN In-Reply-To: <20140611092337.35794bc0@redhat.com> Message-ID: References: <20140608181436.17de69ac@redhat.com> <20140609150353.75eff02b@redhat.com> <20140611092337.35794bc0@redhat.com> Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 11 Jun 2014, Luiz Capitulino wrote: > > The zone should not cross the 8M boundary? > > Yes, but the question is: why? zones need to be aligned so that the huge pages order and other page orders allocated from the page allocator are at their "natural alignment". Otherwise huge pages cannot be mapped properly and various I/O devices may encounter issues if they rely on the natural alignment. > My current thinking, after discussing this with David, is to just page > align the memory range. This should fix the hyperv-triggered bug in 2.6.32 > and seems to be the right thing for upstream too. You need to make sure that the page orders can be allocated at their proper boundaries. -- 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/