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=-7.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 14452C433ED for ; Mon, 12 Apr 2021 12:50:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E02FC61261 for ; Mon, 12 Apr 2021 12:50:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241496AbhDLMuY (ORCPT ); Mon, 12 Apr 2021 08:50:24 -0400 Received: from smtp-good-out-4.t-2.net ([93.103.246.70]:58932 "EHLO smtp-good-out-4.t-2.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238534AbhDLMuX (ORCPT ); Mon, 12 Apr 2021 08:50:23 -0400 X-Greylist: delayed 483 seconds by postgrey-1.27 at vger.kernel.org; Mon, 12 Apr 2021 08:50:22 EDT Received: from smtp-1.t-2.net (smtp-1.t-2.net [IPv6:2a01:260:1:4::1e]) by smtp-good-out-4.t-2.net (Postfix) with ESMTP id 4FJpK41DD6z1VPs; Mon, 12 Apr 2021 14:42:00 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=t-2.net; s=smtp-out-2; t=1618231320; bh=an0I2Pi77+7RFQeYVkdJg3pvIoAezOsYDpfl+GxO9Q0=; h=Subject:From:To:Cc:Date:In-Reply-To:References; b=r3XN6zbfILHQ+PiBr06WKJ3LmzmL/v92jsxQW7h6stnXhR4VYzk42A+hzdfadJRu4 cYnYIR3wqM+XRq6W+aFY5A6jZZT3KA1Z9DrboBzULiBanHqpP8ApipR0e7irrufr/U +rwCPbJm4x9A/Lna4BH+6k9HKxndqsD1F54jvsAw= Received: from localhost (localhost [127.0.0.1]) by smtp-1.t-2.net (Postfix) with ESMTP id 4FJpK413JKzTmgvW; Mon, 12 Apr 2021 14:42:00 +0200 (CEST) X-Virus-Scanned: amavisd-new at t-2.net Received: from smtp-1.t-2.net ([127.0.0.1]) by localhost (smtp-1.t-2.net [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id z6KjXUtJEyly; Mon, 12 Apr 2021 14:41:59 +0200 (CEST) Received: from hpg3.u2up.net (89-212-91-172.static.t-2.net [89.212.91.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp-1.t-2.net (Postfix) with ESMTPS; Mon, 12 Apr 2021 14:41:28 +0200 (CEST) Message-ID: Subject: Re: How to handle concurrent access to /dev/ttyprintk ? From: Samo =?UTF-8?Q?Poga=C4=8Dnik?= To: Tetsuo Handa Cc: Petr Mladek , Jiri Slaby , Sergey Senozhatsky , Steven Rostedt , John Ogness , linux-kernel@vger.kernel.org, Greg Kroah-Hartman Date: Mon, 12 Apr 2021 14:41:27 +0200 In-Reply-To: References: <20210403041444.4081-1-penguin-kernel@I-love.SAKURA.ne.jp> <3c15d32f-c568-7f6f-fa7e-af4deb9b49f9@i-love.sakura.ne.jp> <051b550c-1cdd-6503-d2b7-0877bf0578fc@i-love.sakura.ne.jp> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dne 12.04.2021 (pon) ob 19:39 +0900 je Tetsuo Handa napisal(a): > What is the intended usage of /dev/ttyprintk ? > The intended use of 'ttyprintk' is to redirect console to /dev/ttyprintk via the TIOCCONS ioctl. After successfull redirection, all console messages get "merged" with kernel messages and as such automatically processed (stored/transferred) by the syslog service for example. best regards, Samo