Received: by 2002:ac2:5a04:0:0:0:0:0 with SMTP id q4csp942153lfn; Fri, 18 Feb 2022 01:12:45 -0800 (PST) X-Google-Smtp-Source: ABdhPJzt88601RZ40S3zh0BYh455njAe2ZvgllOHM4/mz5ZanfdI5yBsFXMRL3JcXEGa75mubtWb X-Received: by 2002:a17:907:7815:b0:6ce:5242:1280 with SMTP id la21-20020a170907781500b006ce52421280mr5644663ejc.217.1645175565310; Fri, 18 Feb 2022 01:12:45 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1645175565; cv=none; d=google.com; s=arc-20160816; b=C865MSil/VWcwhunKHqlBvCQ8X3L+mlYrGOIKX4JA3yv7swgvJh4RcCS1f0JpPnkrV MmKguln3c99PqdakZpW+pSRovAfMmCP10oPqgRA4L/LOV2Hjhm4Ak3iUSRQNnHma86+1 e6Nw5EDAowAsHwe/D6+1SQ57hTG1Z7Ni9XnHAMVcFS1tkUP0NushQs6hf9WL2S7D5SGA gX7mlTeMJmjjTFh7NsXjcCypSzmNFE/RlLFiPeU1CO0ReuKYw2d3LrOCBe5U1Os+Ehq4 RZzw0aW4GR1wxE/DUFO4YnSVpCRlNbHND5UvzGo/DbCz1O+TfefKzLQwgm0+Bi3qxv5q VjFA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:content-language :mime-version:accept-language:in-reply-to:references:message-id:date :thread-index:thread-topic:subject:cc:to:from; bh=zOPsnz7VVlMG4d/mzK9BVIvv78CrUU2cniACuBNDCC8=; b=ROLRIskM5mjgnTXFeeqyf+O0Dl6+f64F+FUBCkoog6HGQUWMl8Qxkq+p/GDQ9gF4Rm zwrZIS2JOOJNkaoKqzN7Cw+z2HJekmH+9TH8jUslX21DsXKpPRvJOeUVNE+81IDl7H5h NZKZ7gbazEs0id+/CfzH8GvAjGiLrwp97BMdO9u7JOHLq5iM8BZ9JlGPp452UTX+pqcB IqzjVHOC24KyhjUSEhMaCwzVUnUaAyB6I6dPQgd5Eiol0hH86/BUHj5q3VgolLwDxUP6 VCG1/zPbNa5ElL+uAIn2jnMKYtq5tn5pVQnxcAL7OG638rVc7xTQb08og+LXJRqEb3QN IMuQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=aculab.com Return-Path: Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id g12si6912557edz.238.2022.02.18.01.12.21; Fri, 18 Feb 2022 01:12:45 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=aculab.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232952AbiBRJBJ convert rfc822-to-8bit (ORCPT + 99 others); Fri, 18 Feb 2022 04:01:09 -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 X-Spam-Status: No, score=-2.6 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net 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)