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,URIBL_BLOCKED,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 0D484C55186 for ; Fri, 24 Apr 2020 16:35:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC255206D7 for ; Fri, 24 Apr 2020 16:35:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728518AbgDXQfA (ORCPT ); Fri, 24 Apr 2020 12:35:00 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:55531 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726793AbgDXQe4 (ORCPT ); Fri, 24 Apr 2020 12:34:56 -0400 Received: from fsav106.sakura.ne.jp (fsav106.sakura.ne.jp [27.133.134.233]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 03OGYIuD058791; Sat, 25 Apr 2020 01:34:18 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav106.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav106.sakura.ne.jp); Sat, 25 Apr 2020 01:34:18 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav106.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 03OGYIWV058787 (version=TLSv1.2 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Sat, 25 Apr 2020 01:34:18 +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 , linux-kernel@vger.kernel.org, Dmitry Safonov , Michal Hocko , Yafang Shao References: <20200424024239.63607-1-penguin-kernel@I-love.SAKURA.ne.jp> <20200424092816.62a61b1d@gandalf.local.home> <579fbe97-9aae-2b67-03ff-01291b9cbb7d@i-love.sakura.ne.jp> <20200424103131.7987f890@gandalf.local.home> <7ec0b0a3-39ae-0f1c-b8c2-e1e9e60f1223@i-love.sakura.ne.jp> <20200424114225.5a3bab7e@gandalf.local.home> <20200424122146.163b1680@gandalf.local.home> From: Tetsuo Handa Message-ID: <78c4a174-bc44-8baa-e731-8e36b62df29f@i-love.sakura.ne.jp> Date: Sat, 25 Apr 2020 01:34:15 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200424122146.163b1680@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 2020/04/25 1:21, Steven Rostedt wrote: > On Sat, 25 Apr 2020 01:10:15 +0900 > Tetsuo Handa wrote: > >> KERN_NO_CONSOLES is a mechanism for implementing user decided policy. As long as >> userspace can control whether to use KERN_NO_CONSOLES (e.g. sysctl), there should >> be no problem with adding KERN_NO_CONSOLES (i.e. this patch) to the kernel side. > > How would you define what gets "KERN_NO_CONSOLES"? Is it going to be a > sysctl switch? Yes. See https://lkml.kernel.org/r/c95dfafb-fe9c-19d7-8d42-bcd7d0946867@i-love.sakura.ne.jp . > > Also, how does one control the log level of prints with KERN_NO_CONSOLES? I couldn't understand the question. KERN_NO_CONSOLES is just a flag for not to call call_console_drivers(). Messages printed with printk(KERN_$LOGLEVEL KERN_NO_CONSOLES ...) will be read by userspace syslog daemon and be filtered based on KERN_$LOGLEVEL.