Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750893AbbLQFC1 (ORCPT ); Thu, 17 Dec 2015 00:02:27 -0500 Received: from mgwym04.jp.fujitsu.com ([211.128.242.43]:28732 "EHLO mgwym04.jp.fujitsu.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750714AbbLQFC0 (ORCPT ); Thu, 17 Dec 2015 00:02:26 -0500 X-SecurityPolicyCheck: OK by SHieldMailChecker v2.3.2 X-SHieldMailCheckerPolicyVersion: FJ-ISEC-20150223 X-SHieldMailCheckerMailID: fa1fb89a3b394649a3ca925e20792f43 Subject: Re: [PATCH v3 2/2] mm: Introduce kernelcore=mirror option To: Xishi Qiu References: <1449631109-14756-1-git-send-email-izumi.taku@jp.fujitsu.com> <1449631177-14863-1-git-send-email-izumi.taku@jp.fujitsu.com> <56679FDC.1080800@huawei.com> <3908561D78D1C84285E8C5FCA982C28F39F7F4CD@ORSMSX114.amr.corp.intel.com> <5668D1FA.4050108@huawei.com> <56691819.3040105@huawei.com> <566A9AE1.7020001@huawei.com> <56722258.6030800@huawei.com> <567223A7.9090407@jp.fujitsu.com> <56723E8B.8050201@huawei.com> Cc: "Izumi, Taku" , "Luck, Tony" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "akpm@linux-foundation.org" , "mel@csn.ul.ie" , "Hansen, Dave" , "matt@codeblueprint.co.uk" From: Kamezawa Hiroyuki Message-ID: <567241BE.5030806@jp.fujitsu.com> Date: Thu, 17 Dec 2015 14:01:50 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <56723E8B.8050201@huawei.com> Content-Type: text/plain; charset=iso-2022-jp Content-Transfer-Encoding: 7bit X-TM-AS-MML: disable Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2575 Lines: 85 On 2015/12/17 13:48, Xishi Qiu wrote: > On 2015/12/17 10:53, Kamezawa Hiroyuki wrote: > >> On 2015/12/17 11:47, Xishi Qiu wrote: >>> On 2015/12/17 9:38, Izumi, Taku wrote: >>> >>>> Dear Xishi, >>>> >>>> Sorry for late. >>>> >>>>> -----Original Message----- >>>>> From: Xishi Qiu [mailto:qiuxishi@huawei.com] >>>>> Sent: Friday, December 11, 2015 6:44 PM >>>>> To: Izumi, Taku/泉 拓 >>>>> Cc: Luck, Tony; linux-kernel@vger.kernel.org; linux-mm@kvack.org; akpm@linux-foundation.org; Kamezawa, Hiroyuki/亀澤 寛 >>>>> 之; mel@csn.ul.ie; Hansen, Dave; matt@codeblueprint.co.uk >>>>> Subject: Re: [PATCH v3 2/2] mm: Introduce kernelcore=mirror option >>>>> >>>>> On 2015/12/11 13:53, Izumi, Taku wrote: >>>>> >>>>>> Dear Xishi, >>>>>> >>>>>>> Hi Taku, >>>>>>> >>>>>>> Whether it is possible that we rewrite the fallback function in buddy system >>>>>>> when zone_movable and mirrored_kernelcore are both enabled? >>>>>> >>>>>> What does "when zone_movable and mirrored_kernelcore are both enabled?" mean ? >>>>>> >>>>>> My patchset just provides a new way to create ZONE_MOVABLE. >>>>>> >>>>> >>>>> Hi Taku, >>>>> >>> >>> Hi Taku, >>> >>> We can NOT specify kernelcore= "nn[KMG]" and "mirror" at the same time. >>> So when we use "mirror", in fact, the movable zone is a new zone. I think it is >>> more appropriate with this name "mirrored zone", and also we can rewrite the >>> fallback function in buddy system in this case. >> >> kernelcore ="mirrored zone" ? > > No, it's zone_names[MAX_NR_ZONES] > How about "Movable", -> "Non-mirrored"? > That will break many user apps. I think we don't have enough reason. >> >> BTW, let me confirm. >> >> ZONE_NORMAL = mirrored >> ZONE_MOVABLE = not mirrored. >> > > Yes, > >> so, the new zone is "not-mirrored" zone. >> >> Now, fallback function is >> >> movable -> normal -> DMA. >> >> As Tony requested, we may need a knob to stop a fallback in "movable->normal", later. >> > > If the mirrored memory is small and the other is large, > I think we can both enable "non-mirrored -> normal" and "normal -> non-mirrored". Size of mirrored memory can be configured by software(EFI var). So, having both is just overkill and normal->non-mirroed fallback is meaningless considering what the feature want to guarantee. Thanks, -Kame -- 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/