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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 7E1E4C18E5B for ; Mon, 16 Mar 2020 18:35:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 50F9B20679 for ; Mon, 16 Mar 2020 18:35:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732355AbgCPSfV (ORCPT ); Mon, 16 Mar 2020 14:35:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:33180 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731967AbgCPSfV (ORCPT ); Mon, 16 Mar 2020 14:35:21 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4C38620674; Mon, 16 Mar 2020 18:35:19 +0000 (UTC) Date: Mon, 16 Mar 2020 14:35:17 -0400 From: Steven Rostedt To: Eugeniu Rosca Cc: linux-kernel@vger.kernel.org, Petr Mladek , Sergey Senozhatsky , Ingo Molnar , Thomas Gleixner , Peter Zijlstra , Jisheng Zhang , Valdis Kletnieks , Sebastian Andrzej Siewior , Andrew Gabbasov , Dirk Behme , Eugeniu Rosca Subject: Re: [RFC PATCH 0/3] Fix quiet console in pre-panic scenarios Message-ID: <20200316143517.651abbeb@gandalf.local.home> In-Reply-To: <20200315170903.17393-1-erosca@de.adit-jv.com> References: <20200315170903.17393-1-erosca@de.adit-jv.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 15 Mar 2020 18:09:00 +0100 Eugeniu Rosca wrote: > Dear community, > > The motivation behind this seris is to save days/weeks, if not months, > of debugging efforts for users who: > > * experience an issue like softlockup/hardlockup/hung task/oom, whose > reproduction is not clear and whose occurrence rate is very low > * are constrained to use a low loglevel value (1,2,3) in production > * mostly rely on console logs to debug the issue post-mortem > (e.g. saved to persistent storage via e.g. pstore) > > As pointed out in the last patch from this series, under the above > circumstances, users might simply lack any relevant logs during > post-mortem analysis. > > Why this series is marked as RFC is because: > * There are several possible approaches to turn console verbosity on > and off. Current series employs the 'ignore_loglevel' functionality, > but an alternative way is to use the 'console_loglevel' variable. The > latter is more intrusive, hence the former has been chosen as v1. > * Manipulating 'ignore_loglevel' might be seen as an abuse, especially > because it breaks the expectation of users who assume the system to > be dead silent after passing loglevel=0 on kernel command line. > > Thank you for your comments! I don't see any issues with this patch set. What do others think? Acked-by: Steven Rostedt (VMware) [ Note, I only acked, and did not give a deep review of it ] -- Steve > > Eugeniu Rosca (3): > printk: convert ignore_loglevel to atomic_t > printk: add console_verbose_{start,end} > watchdog: Turn console verbosity on when reporting softlockup > > include/linux/printk.h | 10 ++++++++++ > kernel/printk/printk.c | 30 ++++++++++++++++++++++++++---- > kernel/watchdog.c | 4 ++++ > 3 files changed, 40 insertions(+), 4 deletions(-) >