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 1EA41C00144 for ; Mon, 1 Aug 2022 15:45:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233004AbiHAPp1 convert rfc822-to-8bit (ORCPT ); Mon, 1 Aug 2022 11:45:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47690 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232660AbiHAPpT (ORCPT ); Mon, 1 Aug 2022 11:45:19 -0400 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 CD1FF5F8E for ; Mon, 1 Aug 2022 08:45:17 -0700 (PDT) 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-139-bxhUQFspMBSGjvyo25nw2A-1; Mon, 01 Aug 2022 16:45:14 +0100 X-MC-Unique: bxhUQFspMBSGjvyo25nw2A-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 15.0.1497.36; Mon, 1 Aug 2022 16:45:13 +0100 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.036; Mon, 1 Aug 2022 16:45:13 +0100 From: David Laight To: 'Petr Mladek' , Linus Torvalds CC: Sergey Senozhatsky , Steven Rostedt , John Ogness , "Andy Shevchenko" , Rasmus Villemoes , Sebastian Andrzej Siewior , Thomas Gleixner , Jan Kara , Peter Zijlstra , "linux-kernel@vger.kernel.org" Subject: RE: [GIT PULL] printk for 5.20 Thread-Topic: [GIT PULL] printk for 5.20 Thread-Index: AQHYpbiurCjhEtlBF0OMnCiDcM8gDa2aL60w Date: Mon, 1 Aug 2022 15:45:13 +0000 Message-ID: <16ef8dbc4bdf4120b046ebacaf1f3cf2@AcuMS.aculab.com> References: 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 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 > - Completely disable printing on consoles with CONFIG_RT. They break > RT guarantees. They are too slow to be called with raw spinlocks. > They can't be called with normal spinlocks in an atomic context because > RT spinlocks might sleep. It is going to get fixed by the kthreads and > atomic consoles. In the meantime, the debugging of CONFIG_RT kernel > will be possible only by the user space kernel log readers. SYSV used to be like that if you were running syslogd. Used to make debugging some issues completely impossible. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)