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=-2.5 required=3.0 tests=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 4D5E7C433E0 for ; Thu, 2 Jul 2020 13:32:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2161120780 for ; Thu, 2 Jul 2020 13:32:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729344AbgGBNcf (ORCPT ); Thu, 2 Jul 2020 09:32:35 -0400 Received: from mx2.suse.de ([195.135.220.15]:37896 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729119AbgGBNcf (ORCPT ); Thu, 2 Jul 2020 09:32:35 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id F0F89BC6C; Thu, 2 Jul 2020 13:32:33 +0000 (UTC) Date: Thu, 2 Jul 2020 15:31:10 +0200 From: Petr Mladek To: lijiang Cc: John Ogness , 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 Subject: Re: [PATCH v3 3/3] printk: use the lockless ringbuffer Message-ID: <20200702133110.GE14288@alley> References: <20200618144919.9806-1-john.ogness@linutronix.de> <20200618144919.9806-4-john.ogness@linutronix.de> <87zh8imgs5.fsf@jogness.linutronix.de> <585a6a1b-931c-1034-e2cc-da2c4381751e@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <585a6a1b-931c-1034-e2cc-da2c4381751e@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 2020-07-02 17:43:22, lijiang wrote: > 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. I agree that this three are the most important ones and should be enough. Thanks a lot for working on it and testing it. Best Regards, Petr