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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A55A1C433F5 for ; Wed, 15 Dec 2021 03:44:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=AkZU6HjhUKM4IX1jOoiDoMkrImCpTYdtaizruLT6FcM=; b=aVknVE5W4x+qI2 lZHuwGSf97rstw4C+9FNdsfUPuah+k4sR7oR8IcP+AiHBAhjordwHK8iOASs+LUr9Tvj65BLmf42i OzJrRmC5hgppD+EFiuW1kXv+GCI7PWuzASLBy9Fku1PySVZsGT56qDRgjZjww9k7LgYuEjYUHtBid DkWA1Y4wZG8EtnOlQQFRf4N2zPY90IHfSVpUsMgxgMIe/pW5ZgtjQUqPY+VdSk29VYLSSmavGvp1w +ZrXVGL2axB/6yUTbQroxBX3EChP35/jXfigmqVJRmvhDUBgk2oB1w0RxRF2+HAY7N6DBjzLXAlfW dJITTbdI4dpe8MJKD54A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mxLBi-00GYOG-64; Wed, 15 Dec 2021 03:42:42 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mxLBc-00GYMa-LR for linux-arm-kernel@lists.infradead.org; Wed, 15 Dec 2021 03:42:39 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1639539755; 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=UKPN2S3SXVfn+2YMA0tbS8ft/AvqrEmCxTbCDiXtIYc=; b=OB6jIeZg7igrmT646CQBfuL77xopiC7vabLYRN3JayT64abSNfnk/5eQv495J26Uv+wJfe R3n/SQsu/54Da28pDSdJ5cbY3bEEvRhbCbv/mf+iuA7Sb/eod4D0VLGEfBUzqG7sVC34Jh 4CfQNldSS09EjvKy0Hygz1sc2c0w1I4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-191-0POoudTmOk2yvbrwSVZmvw-1; Tue, 14 Dec 2021 22:42:31 -0500 X-MC-Unique: 0POoudTmOk2yvbrwSVZmvw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id AEA6C1006AA0; Wed, 15 Dec 2021 03:42:28 +0000 (UTC) Received: from localhost (ovpn-12-120.pek2.redhat.com [10.72.12.120]) by smtp.corp.redhat.com (Postfix) with ESMTPS id ED62E752D7; Wed, 15 Dec 2021 03:42:21 +0000 (UTC) Date: Wed, 15 Dec 2021 11:42:19 +0800 From: Baoquan He To: Borislav Petkov , Catalin Marinas Cc: Zhen Lei , Thomas Gleixner , Ingo Molnar , x86@kernel.org, "H . Peter Anvin" , linux-kernel@vger.kernel.org, Dave Young , Vivek Goyal , Eric Biederman , kexec@lists.infradead.org, Will Deacon , linux-arm-kernel@lists.infradead.org, Rob Herring , Frank Rowand , devicetree@vger.kernel.org, Jonathan Corbet , linux-doc@vger.kernel.org, Randy Dunlap , Feng Zhou , Kefeng Wang , Chen Zhou Subject: Re: [PATCH v17 02/10] x86: kdump: make the lower bound of crash kernel reservation consistent Message-ID: <20211215034219.GB10336@MiWiFi-R3L-srv> References: <20211210065533.2023-1-thunder.leizhen@huawei.com> <20211210065533.2023-3-thunder.leizhen@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211214_194236_835299_51E29EB4 X-CRM114-Status: GOOD ( 20.18 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 12/14/21 at 07:24pm, Catalin Marinas wrote: > On Tue, Dec 14, 2021 at 08:07:58PM +0100, Borislav Petkov wrote: > > On Fri, Dec 10, 2021 at 02:55:25PM +0800, Zhen Lei wrote: > > > From: Chen Zhou > > > > > > The lower bounds of crash kernel reservation and crash kernel low > > > reservation are different, use the consistent value CRASH_ALIGN. > > > > A big WHY is missing here to explain why the lower bound of the > > allocation range needs to be 16M and why was 0 wrong? > > I asked the same here: > > https://lore.kernel.org/r/20210224143547.GB28965@arm.com > > IIRC Baoquan said that there is a 1MB reserved for x86 anyway in the > lower part, so that's equivalent in practice to starting from > CRASH_ALIGN. Yeah, even for i386, there's area reserved by BIOS inside low 1M. Considering the existing alignment CRASH_ALIGN which is 16M, we definitely have no chance to get memory starting from 0. So starting from 16M can skip the useless memblock searching, and make the crashkernel low reservation consisten with crashkernel reservation on allocation code. > > Anyway, I agree the commit log should describe this. Yes, totally. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel