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 040C4C2D0F8 for ; Wed, 13 May 2020 07:59:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D317020740 for ; Wed, 13 May 2020 07:59:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729668AbgEMH7a (ORCPT ); Wed, 13 May 2020 03:59:30 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:60598 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729026AbgEMH73 (ORCPT ); Wed, 13 May 2020 03:59:29 -0400 Received: from fsav102.sakura.ne.jp (fsav102.sakura.ne.jp [27.133.134.229]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 04D7wmll060488; Wed, 13 May 2020 16:58:48 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav102.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav102.sakura.ne.jp); Wed, 13 May 2020 16:58:48 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav102.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 04D7wmvC060483 (version=TLSv1.2 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 13 May 2020 16:58:48 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Subject: Re: [PATCH] printk: Add loglevel for "do not print to consoles". To: Sergey Senozhatsky Cc: Michal Hocko , Petr Mladek , Steven Rostedt , linux-kernel@vger.kernel.org, Dmitry Safonov , Yafang Shao References: <20200425004609.GE8982@jagdpanzerIV.localdomain> <842ff40b-a232-6098-4333-996a3033b30a@i-love.sakura.ne.jp> <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> From: Tetsuo Handa Message-ID: Date: Wed, 13 May 2020 16:58:48 +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: <20200513062652.GM413@jagdpanzerIV.localdomain> 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 15:26, Sergey Senozhatsky wrote: > Yes, but this looks like it's the consumer of the messages who > decides what to filter and what not to. rsyslog, dmesg, etc. > will have different filtering policies. It's not like the kernel > decides what to hide and what to show. If would compare this to > NO_CONSOLES, then NO_CONSOLES does a different thing after all. I just showed an example that changing dump_tasks() messages from KERN_INFO to KERN_DEBUG is not an option. If dump_tasks() were using KERN_DEBUG, the consumer of the messages will have to receive all KERN_DEBUG messages, which needlessly contains uninterested messages. If dump_tasks() allows use of NO_CONSOLES (via e.g. sysctl switch), the consumer does not need to receive KERN_DEBUG messages. What is wrong with adding NO_CONSOLES ?