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=-6.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 E0312C433E1 for ; Wed, 19 Aug 2020 12:04:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A88AF205CB for ; Wed, 19 Aug 2020 12:04:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="N89EMM+D" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728344AbgHSMEA (ORCPT ); Wed, 19 Aug 2020 08:04:00 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:26330 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728358AbgHSMDk (ORCPT ); Wed, 19 Aug 2020 08:03:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1597838618; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=m9+0bAxLuUQbDhStzV9Q7LQwgzKpdo+DUCTWFOEtQPc=; b=N89EMM+Df1NfsAsDtGUcT8iRMU8piiaEhhvDKpiicSe1fCElL8tu9sbyCq9l3ShYfBjSoh uqFMYi3sqFAN9vBKCYH77qd7TWrHx5EgAxAp6BCjlGm+GNkDzrhyWNdPZKm5NPPY7T7IP+ 0aFKlm/yKU1V8PamcAPzoDRdqxBMI2c= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-569-9z5gyIZuP6iSl37NVFxRVQ-1; Wed, 19 Aug 2020 08:03:16 -0400 X-MC-Unique: 9z5gyIZuP6iSl37NVFxRVQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E754A801AE5; Wed, 19 Aug 2020 12:03:12 +0000 (UTC) Received: from dhcp-128-65.nay.redhat.com (ovpn-13-194.pek2.redhat.com [10.72.13.194]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D5C947A421; Wed, 19 Aug 2020 12:03:04 +0000 (UTC) Date: Wed, 19 Aug 2020 20:03:01 +0800 From: Dave Young To: chenzhou Cc: catalin.marinas@arm.com, will@kernel.org, james.morse@arm.com, tglx@linutronix.de, mingo@redhat.com, bhe@redhat.com, corbet@lwn.net, John.P.donnelly@oracle.com, prabhakar.pkin@gmail.com, bhsharma@redhat.com, horms@verge.net.au, robh+dt@kernel.org, arnd@arndb.de, nsaenzjulienne@suse.de, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-doc@vger.kernel.org, guohanjun@huawei.com, xiexiuqi@huawei.com, huawei.libin@huawei.com, wangkefeng.wang@huawei.com Subject: Re: [PATCH v11 5/5] kdump: update Documentation about crashkernel Message-ID: <20200819120301.GA13727@dhcp-128-65.nay.redhat.com> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2e6aebf9-3765-5d8c-933c-698442db1d52@huawei.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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:) > > 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 > > > > > > . > > > >