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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 4FCAFC433DF for ; Thu, 20 Aug 2020 08:49:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 26F922078B for ; Thu, 20 Aug 2020 08:49:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726846AbgHTItn convert rfc822-to-8bit (ORCPT ); Thu, 20 Aug 2020 04:49:43 -0400 Received: from eu-smtp-delivery-151.mimecast.com ([207.82.80.151]:49013 "EHLO eu-smtp-delivery-151.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725852AbgHTItl (ORCPT ); Thu, 20 Aug 2020 04:49:41 -0400 Received: from AcuMS.aculab.com (156.67.243.126 [156.67.243.126]) (Using TLS) by relay.mimecast.com with ESMTP id uk-mta-288-d7-TPSH4OvWJ7EFK_h5PYw-1; Thu, 20 Aug 2020 09:49:36 +0100 X-MC-Unique: d7-TPSH4OvWJ7EFK_h5PYw-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) by AcuMS.aculab.com (fd9f:af1c:a25b:0:43c:695e:880f:8750) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Thu, 20 Aug 2020 09:49:35 +0100 Received: from AcuMS.Aculab.com ([fe80::43c:695e:880f:8750]) by AcuMS.aculab.com ([fe80::43c:695e:880f:8750%12]) with mapi id 15.00.1347.000; Thu, 20 Aug 2020 09:49:35 +0100 From: David Laight To: 'Joe Perches' , John Ogness , Linus Torvalds CC: Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Greg Kroah-Hartman , Thomas Gleixner , Sergey Senozhatsky , "linux-kernel@vger.kernel.org" Subject: RE: [RFC PATCH 1/5] printk: implement pr_cont_t Thread-Topic: [RFC PATCH 1/5] printk: implement pr_cont_t Thread-Index: AQHWdomYXzVvufyPxEOt+PNltcCbQKlAmzJg///2oQCAAB0uoA== Date: Thu, 20 Aug 2020 08:49:35 +0000 Message-ID: <389a62f178d2482b9525f499b82e92df@AcuMS.aculab.com> References: <20200819232632.13418-1-john.ogness@linutronix.de> <20200819232632.13418-2-john.ogness@linutronix.de> <29b6120680fbfb51936bb9100b2c9bb78385aef0.camel@perches.com> In-Reply-To: <29b6120680fbfb51936bb9100b2c9bb78385aef0.camel@perches.com> Accept-Language: en-GB, en-US Content-Language: 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: 0.001 X-Mimecast-Originator: aculab.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joe Perches > Sent: 20 August 2020 09:00 > > On Thu, 2020-08-20 at 07:44 +0000, David Laight wrote: > > I've no idea how you'd 'size' the number of buffers. > > I believe they are static and assume no more than 10 > simultaneous uses of printk_begin What I meant was how you'd work out whether 10 was in any way appropriate. ISTM it is either 'too many' or 'nowhere near enough' depending on exactly what the system is doing. And if code 'leaks' them you are in deep doo-doos. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)