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=-2.2 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 2299DC2D0FA for ; Wed, 13 May 2020 14:04:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A71A320659 for ; Wed, 13 May 2020 14:04:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388836AbgEMOEE (ORCPT ); Wed, 13 May 2020 10:04:04 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:55136 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388325AbgEMOED (ORCPT ); Wed, 13 May 2020 10:04:03 -0400 Received: from fsav302.sakura.ne.jp (fsav302.sakura.ne.jp [153.120.85.133]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 04DE3MOo098927; Wed, 13 May 2020 23:03:22 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav302.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav302.sakura.ne.jp); Wed, 13 May 2020 23:03:22 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav302.sakura.ne.jp) Received: from [192.168.1.9] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 04DE3LDg098920 (version=TLSv1.2 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 13 May 2020 23:03:21 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Subject: Re: [PATCH] printk: Add loglevel for "do not print to consoles". To: Steven Rostedt Cc: Petr Mladek , Sergey Senozhatsky , Michal Hocko , linux-kernel@vger.kernel.org, Dmitry Safonov , Yafang Shao References: <20200427062117.GC486@jagdpanzerIV.localdomain> <4dae86af-1d9a-f5a8-cff6-aa91ec038a79@i-love.sakura.ne.jp> <20200428121828.GP28637@dhcp22.suse.cz> <20200428154532.GU28637@dhcp22.suse.cz> <20200429142106.GG28637@dhcp22.suse.cz> <20200513062652.GM413@jagdpanzerIV.localdomain> <20200513100413.GH17734@linux-b0ei> <20564555-7b84-f716-5dcd-978f76ad459a@i-love.sakura.ne.jp> <20200513094642.56bf50f7@gandalf.local.home> From: Tetsuo Handa Message-ID: <355d1700-4d33-4604-4187-27fd994bf473@i-love.sakura.ne.jp> Date: Wed, 13 May 2020 23:03:19 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200513094642.56bf50f7@gandalf.local.home> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/05/13 22:46, Steven Rostedt wrote: > On Wed, 13 May 2020 20:03:53 +0900 > Tetsuo Handa wrote: > >> I think that basically only oops (e.g. WARN()/BUG()/panic()) messages worth >> printing to consoles and the rest messages do not worth printing to consoles. >> Existing KERN_$LOGLEVEL is too rough-grained. > > And this statement is exactly why I believe you are wrong. > > Because *I* think messages to the console is more important than messages > to the logs. Several of my servers are only monitored by the console. I > seldom look at the logs on those machines. As a technical staff at a support center, I can never monitor the consoles of customer's servers. I can examine only syslog messages saved as /var/log/messages . > > This is a policy decision, and must be made by user space. Your use case is > not applicable to everyone else's use case. And should not be set in stone > by the kernel. My proposal does not set in stone by the kernel. My proposal is gives users a chance to control whether to print to consoles. On 2020/05/13 22:55, Steven Rostedt wrote: > On Wed, 13 May 2020 20:03:53 +0900 > Tetsuo Handa wrote: > >> I think that basically only oops (e.g. WARN()/BUG()/panic()) messages worth >> printing to consoles and the rest messages do not worth printing to consoles. >> Existing KERN_$LOGLEVEL is too rough-grained. > > Why don't you look into having a "noconsole" command line option that will > not print anything to the consoles but oops messages. I can't force customers to use "noconsole" command line option. That's a too rough-grained boolean. > > Sounds more like what you would like, and something that perhaps would be > acceptable by the larger community.