Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757676AbcDEKXh (ORCPT ); Tue, 5 Apr 2016 06:23:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48664 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751433AbcDEKXg (ORCPT ); Tue, 5 Apr 2016 06:23:36 -0400 Reply-To: xlpang@redhat.com Subject: Re: [PATCH v2] s390/kexec: Consolidate crash_map/unmap_reserved_pages() and arch_kexec_protect(unprotect)_crashkres() References: <1459840199-19920-1-git-send-email-xlpang@redhat.com> <20160405111316.2fa4772c@holzheu> To: Michael Holzheu Cc: linux-kernel@vger.kernel.org, kexec@lists.infradead.org, akpm@linux-foundation.org, ebiederm@xmission.com, Minfei Huang , Vivek Goyal , Baoquan He , Heiko Carstens From: Xunlei Pang Message-ID: <57039223.7020903@redhat.com> Date: Tue, 5 Apr 2016 18:23:31 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <20160405111316.2fa4772c@holzheu> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1359 Lines: 35 On 2016/04/05 at 17:13, Michael Holzheu wrote: > Hello Xunlei, > > On Tue, 5 Apr 2016 15:09:59 +0800 > Xunlei Pang wrote: >> Commit 3f625002581b ("kexec: introduce a protection mechanism >> for the crashkernel reserved memory") is a similar mechanism >> for protecting the crash kernel reserved memory to previous >> crash_map/unmap_reserved_pages() implementation, the new one >> is more generic in name and cleaner in code (besides, some >> arch may not be allowed to unmap the pgtable). >> >> Therefore, this patch consolidates them, and uses the new >> arch_kexec_protect(unprotect)_crashkres() to replace former >> crash_map/unmap_reserved_pages() which by now has been only >> used by S390. >> >> The consolidation work needs the crash memory to be mapped >> initially, so get rid of S390 crash kernel memblock removal >> in reserve_crashkernel(). Oops, the final paragraph of the changelog should be changed to: The consolidation work needs the crash memory to be mapped initially, this is done in machine_kdump_pm_init() which is run after reserve_crashkernel(). Once kdump kernel is loaded, the new arch_kexec_protect_crashkres() implemented for S390 will actually unmap the pgtable like before. > If you fix this comment, I am fine with your patch. > > Acked-by: Michael Holzheu > Thanks, Xunlei