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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 411C4C433EF for ; Sat, 7 May 2022 18:50:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242301AbiEGSyS (ORCPT ); Sat, 7 May 2022 14:54:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50404 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241402AbiEGSyS (ORCPT ); Sat, 7 May 2022 14:54:18 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A2798DF06; Sat, 7 May 2022 11:50:30 -0700 (PDT) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 2A4CE6142F; Sat, 7 May 2022 18:50:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6CE0BC385A5; Sat, 7 May 2022 18:50:25 +0000 (UTC) Date: Sat, 7 May 2022 19:50:21 +0100 From: Catalin Marinas To: Baoquan He Cc: Zhen Lei , Thomas Gleixner , Ingo Molnar , Borislav Petkov , 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 , John Donnelly , Dave Kleikamp Subject: Re: [PATCH v24 3/6] arm64: kdump: Reimplement crashkernel=X Message-ID: References: <20220506114402.365-1-thunder.leizhen@huawei.com> <20220506114402.365-4-thunder.leizhen@huawei.com> <20220506231032.GA122876@MiWiFi-R3L-srv> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220506231032.GA122876@MiWiFi-R3L-srv> Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Sat, May 07, 2022 at 07:10:32AM +0800, Baoquan He wrote: > On 05/06/22 at 07:43pm, Zhen Lei wrote: > ...... > > @@ -118,8 +162,7 @@ static void __init reserve_crashkernel(void) > > if (crash_base) > > crash_max = crash_base + crash_size; > > > > - /* Current arm64 boot protocol requires 2MB alignment */ > > - crash_base = memblock_phys_alloc_range(crash_size, SZ_2M, > > + crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN, > > crash_base, crash_max); > > if (!crash_base) { > > pr_warn("cannot allocate crashkernel (size:0x%llx)\n", > > @@ -127,6 +170,11 @@ static void __init reserve_crashkernel(void) > > return; > > } > > > > There's corner case missed, e.g > 1) ,high and ,low are specified, CONFIG_ZONE_DMA|DMA32 is not enabled; > 2) ,high and ,low are specified, the whole system memory is under 4G. My view of ,low is that it should only used to override the default ZONE_DMA allocation if that one is not suitable. If no ZONE_DMA exists or everything is ZONE_DMA, ignore it altogether. That's a specialist case for people that know more about the memory layout, otherwise crashkernel=X works in most case with crashkernel=X,high as an alternative to allow high allocation. > I would suggest merging this series, Lei can add this corner case > handling on top. Since this is a newly added support, we don't have > to make it one step. Doing step by step can make reviewing easier. I agree. -- Catalin