From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DBF23C433E7 for ; Fri, 28 Aug 2020 01:59:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BEA5920848 for ; Fri, 28 Aug 2020 01:59:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728370AbgH1B7e (ORCPT ); Thu, 27 Aug 2020 21:59:34 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:51654 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727124AbgH1B7e (ORCPT ); Thu, 27 Aug 2020 21:59:34 -0400 Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id AD070D3F16C2953E7244; Fri, 28 Aug 2020 09:59:31 +0800 (CST) Received: from [127.0.0.1] (10.174.176.220) by DGGEMS410-HUB.china.huawei.com (10.3.19.210) with Microsoft SMTP Server id 14.3.487.0; Fri, 28 Aug 2020 09:59:21 +0800 Subject: Re: [PATCH v11 5/5] kdump: update Documentation about crashkernel To: Dave Young , References: <20200801130856.86625-1-chenzhou10@huawei.com> <20200801130856.86625-6-chenzhou10@huawei.com> <20200808100239.GB60590@dhcp-128-65.nay.redhat.com> <96d0da23-d484-7f66-1680-07b4b5984831@huawei.com> <20200810060355.GB6988@dhcp-128-65.nay.redhat.com> <2e6aebf9-3765-5d8c-933c-698442db1d52@huawei.com> <20200819120301.GA13727@dhcp-128-65.nay.redhat.com> CC: , , , , , , , , , , , , , , , , , , , , From: chenzhou Message-ID: Date: Fri, 28 Aug 2020 09:59:19 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <20200819120301.GA13727@dhcp-128-65.nay.redhat.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.176.220] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Catalin, On 2020/8/19 20:03, Dave Young wrote: > On 08/18/20 at 03:07pm, chenzhou wrote: >> >> On 2020/8/10 14:03, Dave Young wrote: >>> Hi, >>> >>>>> Previously I remember we talked about to use similar logic as X86, but I >>>>> remember you mentioned on some arm64 platform there could be no low >>>>> memory at all. Is this not a problem now for the fallback? Just be >>>>> curious, thanks for the update, for the common part looks good. >>>> Hi Dave, >>>> >>>> Did you mean this discuss: https://lkml.org/lkml/2019/12/27/122? >>> I meant about this reply instead :) >>> https://lkml.org/lkml/2020/1/16/616 >> Hi Dave, >> >> Sorry for not repley in time, I was on holiday last week. > Hi, no problem, thanks for following up. > >> The platform James mentioned may exist for which have no devices and need no low memory. >> For our arm64 server platform, there are some devices and need low memory. >> >> I got it. For the platform with no low memory, reserving crashkernel will always fail. >> How about like this: > I think the question should leave to Catalin or James, I have no > suggestion about this:) Any suggestions about this? Thanks, Chen Zhou > >> diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c >> index a8e34d97a894..4df18c7ea438 100644 >> --- a/arch/arm64/mm/init.c >> +++ b/arch/arm64/mm/init.c >> @@ -147,7 +147,7 @@ static void __init reserve_crashkernel(void) >> } >> memblock_reserve(crash_base, crash_size); >> >> - if (crash_base >= CRASH_ADDR_LOW_MAX) { >> + if (memstart_addr < CRASH_ADDR_LOW_MAX && crash_base >= CRASH_ADDR_LOW_MAX) { >> const char *rename = "Crash kernel (low)"; >> >> if (reserve_crashkernel_low()) { >> >> >> Thanks, >> Chen Zhou >> >>> Thanks >>> Dave >>> >>> >>> . >>> >> > > . >