From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754398AbbJIPIn (ORCPT ); Fri, 9 Oct 2015 11:08:43 -0400 Received: from mga01.intel.com ([192.55.52.88]:13732 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753615AbbJIPIm (ORCPT ); Fri, 9 Oct 2015 11:08:42 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.17,658,1437462000"; d="scan'208";a="823045337" Subject: Re: [PATCH][RFC] mm: Introduce kernelcore=reliable option To: Xishi Qiu , Kamezawa Hiroyuki References: <1444402599-15274-1-git-send-email-izumi.taku@jp.fujitsu.com> <561762DC.3080608@huawei.com> <561787DA.4040809@jp.fujitsu.com> <5617989E.9070700@huawei.com> Cc: Taku Izumi , linux-kernel@vger.kernel.org, linux-mm@kvack.org, tony.luck@intel.com, mel@csn.ul.ie, akpm@linux-foundation.org, Mel Gorman , Ingo Molnar , zhongjiang@huawei.com From: Dave Hansen Message-ID: <5617D878.5060903@intel.com> Date: Fri, 9 Oct 2015 08:08:40 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <5617989E.9070700@huawei.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/09/2015 03:36 AM, Xishi Qiu wrote: > I mean the mirrored region can not at the middle or end of the zone, > BIOS should report the memory like this, > > e.g. > BIOS > node0: 0-4G mirrored, 4-8G mirrored, 8-16G non-mirrored > node1: 16-24G mirrored, 24-32G non-mirrored > > OS > node0: DMA DMA32 are both mirrored, NORMAL(4-8G), MOVABLE(8-16G) > node1: NORMAL(16-24G), MOVABLE(24-32G) I understand if the mirrored regions are always at the start of the zone today, but is that somehow guaranteed going forward on all future hardware? I think it's important to at least consider what we would do if DMA32 turned out to be non-reliable.