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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 744A5C433FE for ; Tue, 14 Dec 2021 19:24:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237399AbhLNTY1 (ORCPT ); Tue, 14 Dec 2021 14:24:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46066 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234275AbhLNTY0 (ORCPT ); Tue, 14 Dec 2021 14:24:26 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6CC2C06173E; Tue, 14 Dec 2021 11:24:25 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id BD7ABCE1A82; Tue, 14 Dec 2021 19:24:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20F59C34604; Tue, 14 Dec 2021 19:24:17 +0000 (UTC) Date: Tue, 14 Dec 2021 19:24:14 +0000 From: Catalin Marinas To: Borislav Petkov Cc: Zhen Lei , Thomas Gleixner , Ingo Molnar , x86@kernel.org, "H . Peter Anvin" , linux-kernel@vger.kernel.org, Dave Young , Baoquan He , 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: References: <20211210065533.2023-1-thunder.leizhen@huawei.com> <20211210065533.2023-3-thunder.leizhen@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. Anyway, I agree the commit log should describe this. -- Catalin