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 X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 74699C433DF for ; Thu, 2 Jul 2020 09:43:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4FDE620760 for ; Thu, 2 Jul 2020 09:43:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="MKguYWN9" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728120AbgGBJnh (ORCPT ); Thu, 2 Jul 2020 05:43:37 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:29698 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726555AbgGBJnh (ORCPT ); Thu, 2 Jul 2020 05:43:37 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1593683016; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Ug+Cs+5MidriBBruTqDP+Dk7+JNAduJmDfJrU4PFZh0=; b=MKguYWN9aMdz6/j/fv3uGLhVmexm29R2QqNDXoIk8P0Um/abponBvo4lgG3GrTFdEdFcUy AtVopWSwEea0AGLTzeao9bz63YfKm1rRIyZU6Lhuc+1eY27N5YPr7+1faL4N9EtSlMryNh 5jS5JZQmcmrq6auLu+IVojj81Win1Gw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-292-naC7fyKDMcq4qvGOvA9KGw-1; Thu, 02 Jul 2020 05:43:32 -0400 X-MC-Unique: naC7fyKDMcq4qvGOvA9KGw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 89553804001; Thu, 2 Jul 2020 09:43:30 +0000 (UTC) Received: from localhost.localdomain (ovpn-12-175.pek2.redhat.com [10.72.12.175]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3827D5C1B0; Thu, 2 Jul 2020 09:43:24 +0000 (UTC) Subject: Re: [PATCH v3 3/3] printk: use the lockless ringbuffer To: John Ogness , Petr Mladek Cc: Peter Zijlstra , Sergey Senozhatsky , Sergey Senozhatsky , Steven Rostedt , Linus Torvalds , Greg Kroah-Hartman , Andrea Parri , Thomas Gleixner , Paul McKenney , kexec@lists.infradead.org, linux-kernel@vger.kernel.org References: <20200618144919.9806-1-john.ogness@linutronix.de> <20200618144919.9806-4-john.ogness@linutronix.de> <87zh8imgs5.fsf@jogness.linutronix.de> From: lijiang Message-ID: <585a6a1b-931c-1034-e2cc-da2c4381751e@redhat.com> Date: Thu, 2 Jul 2020 17:43:22 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <87zh8imgs5.fsf@jogness.linutronix.de> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2020年07月02日 17:02, John Ogness 写道: > On 2020-07-02, lijiang wrote: >> About the VMCOREINFO part, I made some tests based on the kernel patch >> v3, the makedumpfile and crash-utility can work as expected with your >> patch(userspace patch), but, unfortunately, the vmcore-dmesg(kexec-tools) >> can't correctly read the printk ring buffer information, and get the >> following error: >> >> "Missing the log_buf symbol" >> >> The kexec-tools(vmcore-dmesg) should also have a similar patch, just like >> in the makedumpfile and crash-utility. > > Yes, a patch for this is needed (as well as for any other related > software floating around the internet). > > I have no RFC patches for vmcore-dmesg. Looking at the code, I think it > would be quite straight forward to port the makedumpfile patch. I will Yes, it should be a similar patch. > try to make some time for this. > That would be nice. Thank you, John Ogness. > I do not want to patch any other software for this. I think with 3 > examples (crash, makedumpfile, vmcore-dmesg), others should be able to It's good enough to have the patch for the makedumpfile, crash and vmcore-dmesg, which can ensure the kdump(userspace) work well. Thanks. Lianbo > implement the changes to their software without needing my help. > > John Ogness >