Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757447Ab1BJX6D (ORCPT ); Thu, 10 Feb 2011 18:58:03 -0500 Received: from rcsinet10.oracle.com ([148.87.113.121]:19370 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757335Ab1BJX6B (ORCPT ); Thu, 10 Feb 2011 18:58:01 -0500 Message-ID: <4D547B74.1030302@kernel.org> Date: Thu, 10 Feb 2011 15:57:40 -0800 From: Yinghai Lu User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.16) Gecko/20101125 SUSE/3.0.11 Thunderbird/3.0.11 MIME-Version: 1.0 To: Jeremy Fitzhardinge CC: "H. Peter Anvin" , Stefano Stabellini , "linux-kernel@vger.kernel.org" , "tglx@linutronix.de" , "x86@kernel.org" , Konrad Rzeszutek Wilk , Jan Beulich Subject: Re: [PATCH] x86/mm/init: respect memblock reserved regions when destroying mappings References: <4D4A3782.3050702@zytor.com> <4D4ADFAD.7060507@zytor.com> <4D4CA568.70907@goop.org> <4D4E4E0D.2080806@zytor.com> <4D4EF553.6000000@kernel.org> <4D50343E.1020906@kernel.org> <4D504161.2060900@kernel.org> <4D506A85.9030802@goop.org> <4D50B4B5.4050505@kernel.org> <4D519AAA.8070309@zytor.com> <4D547962.8040403@goop.org> In-Reply-To: <4D547962.8040403@goop.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Source-IP: acsmt355.oracle.com [141.146.40.155] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090203.4D547B7A.01BC,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1151 Lines: 26 On 02/10/2011 03:48 PM, Jeremy Fitzhardinge wrote: > On 02/08/2011 11:34 AM, H. Peter Anvin wrote: >> On 02/07/2011 07:12 PM, Yinghai Lu wrote: >>> why punishing native path with those checking? >>> >> What happens if you end up with a reserved range in an unfortunate place >> on real hardware? > > Yes, exactly. The reserved region code isn't very useful if you can't > rely on it to reserve stuff. assume context is under: moving cleanup_highmap() down after brk is concluded, and check memblock_reserved there. one case for that: native path, bootloader could put initrd under 512M. and it is with memblock reserved. if we check those range with memblock_reserved, initial kernel mapping will not be cleaned up. or worse if we are checking if there is any range from __pa(_brk_end) to 512M is with memblock reserved to decide if we need to clean-up highmap. it will skip for whole range. Yinghai -- 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/