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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 902EDC433F5 for ; Fri, 18 Feb 2022 09:00:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232960AbiBRJBK convert rfc822-to-8bit (ORCPT ); Fri, 18 Feb 2022 04:01:10 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:54198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231462AbiBRJBI (ORCPT ); Fri, 18 Feb 2022 04:01:08 -0500 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.86.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 38A531867C4 for ; Fri, 18 Feb 2022 01:00:51 -0800 (PST) Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-117-Paf7cxtnMtCmxTJ17km-zA-1; Fri, 18 Feb 2022 09:00:48 +0000 X-MC-Unique: Paf7cxtnMtCmxTJ17km-zA-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) by AcuMS.aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) with Microsoft SMTP Server (TLS) id 15.0.1497.28; Fri, 18 Feb 2022 09:00:46 +0000 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.028; Fri, 18 Feb 2022 09:00:46 +0000 From: David Laight To: 'Petr Mladek' , John Ogness CC: Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , "linux-kernel@vger.kernel.org" , "Greg Kroah-Hartman" , Jiri Slaby , "Paul E. McKenney" , "Josh Triplett" , Mathieu Desnoyers , Lai Jiangshan , Joel Fernandes , Corey Minyard , Kees Cook , Christian Brauner , Daniel Bristot de Oliveira , Andy Shevchenko , Peter Zijlstra , Daniel Lezcano , "Rafael J. Wysocki" , Mark Brown , Josef Bacik , "Eric W. Biederman" , "Shawn Guo" , Matti Vaittinen , Andrew Morton , Wang Qing , Tejun Heo , Randy Dunlap , Alexander Potapenko , Stephen Boyd , Nicholas Piggin , "rcu@vger.kernel.org" Subject: RE: [PATCH printk v1 09/13] printk: add functions to allow direct printing Thread-Topic: [PATCH printk v1 09/13] printk: add functions to allow direct printing Thread-Index: AQHYI/0/7XPqOu2p+UeF1AvHpJcIY6yZAzcg Date: Fri, 18 Feb 2022 09:00:46 +0000 Message-ID: References: <20220207194323.273637-1-john.ogness@linutronix.de> <20220207194323.273637-10-john.ogness@linutronix.de> In-Reply-To: Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Mon 2022-02-07 20:49:19, John Ogness wrote: > > Once kthread printing is introduced, console printing will no longer > > occur in the context of the printk caller. However, there are some > > special contexts where it is desirable for the printk caller to > > directly print out kernel messages. Yes - most of them. It is going to be pretty impossible to do 'hard' kernel debugging if printk get deferred. Typically there already is a deferral method. The prints aren't done by the kernel, but by syslogd. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)