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 D440CC433EF for ; Thu, 17 Mar 2022 02:39:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356113AbiCQCkP (ORCPT ); Wed, 16 Mar 2022 22:40:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48300 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238395AbiCQCkN (ORCPT ); Wed, 16 Mar 2022 22:40:13 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id BC7CC1FCE7 for ; Wed, 16 Mar 2022 19:38:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1647484737; 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=Fga/72Dz+15Gl8xsajyVRcIv8c/wbF3mEbmhMrQvjPo=; b=DjY4VN/o+LtBDyN9mdom9QOqYqgaLKgs3fTyHoMoKpmFLzTNz0MoBTmH0ylssMema/8etZ gkSqNFZznjM0ELedkT52VS32dyGECzlbE8Wr/KQaV8MTC70e+zxvVOpQty9v4m2m50EZPV B/HWkYoGMKcUePG5Ltp60A5ji6mPMsk= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-523-zswabLVJNkCXL775ojlI1g-1; Wed, 16 Mar 2022 22:38:52 -0400 X-MC-Unique: zswabLVJNkCXL775ojlI1g-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id E0F33185A79C; Thu, 17 Mar 2022 02:38:50 +0000 (UTC) Received: from localhost (ovpn-13-190.pek2.redhat.com [10.72.13.190]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BF137111CD50; Thu, 17 Mar 2022 02:38:41 +0000 (UTC) Date: Thu, 17 Mar 2022 10:38:38 +0800 From: Baoquan He To: Zhen Lei Cc: 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, Catalin Marinas , 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 v21 3/5] arm64: kdump: reimplement crashkernel=X Message-ID: References: <20220227030717.1464-1-thunder.leizhen@huawei.com> <20220227030717.1464-4-thunder.leizhen@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220227030717.1464-4-thunder.leizhen@huawei.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/27/22 at 11:07am, Zhen Lei wrote: > From: Chen Zhou > > There are following issues in arm64 kdump: > 1. We use crashkernel=X to reserve crashkernel below 4G, which > will fail when there is no enough low memory. > 2. If reserving crashkernel above 4G, in this case, crash dump > kernel will boot failure because there is no low memory available ~~ change it to "get boot failure" or "fail to boot" > for allocation. > > To solve these issues, change the behavior of crashkernel=X and > introduce crashkernel=X,[high,low]. crashkernel=X tries low allocation > in DMA zone, and fall back to high allocation if it fails. > We can also use "crashkernel=X,high" to select a region above DMA zone, > which also tries to allocate at least 256M in DMA zone automatically. > "crashkernel=Y,low" can be used to allocate specified size low memory. > > Signed-off-by: Chen Zhou > Co-developed-by: Zhen Lei > Signed-off-by: Zhen Lei