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=-0.8 required=3.0 tests=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 CFBD9C43331 for ; Thu, 5 Sep 2019 21:10:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F043E206DF for ; Thu, 5 Sep 2019 21:10:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404032AbfIEVKz (ORCPT ); Thu, 5 Sep 2019 17:10:55 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:44656 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726936AbfIEVKz (ORCPT ); Thu, 5 Sep 2019 17:10:55 -0400 Received: from localhost ([127.0.0.1] helo=vostro.local) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1i5z1Z-00024X-Hf; Thu, 05 Sep 2019 23:10:37 +0200 From: John Ogness To: Steven Rostedt Cc: Thomas Gleixner , Peter Zijlstra , Petr Mladek , Andrea Parri , Sergey Senozhatsky , Sergey Senozhatsky , Brendan Higgins , Linus Torvalds , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, "contact\@linuxplumbersconf.org" , Theodore Ts'o Subject: Re: [RFC PATCH v4 0/9] printk: new ringbuffer implementation References: <20190807222634.1723-1-john.ogness@linutronix.de> <20190904123531.GA2369@hirez.programming.kicks-ass.net> <20190905130513.4fru6yvjx73pjx7p@pathway.suse.cz> <20190905143118.GP2349@hirez.programming.kicks-ass.net> <20190905121101.60c78422@oasis.local.home> Date: Thu, 05 Sep 2019 23:10:34 +0200 In-Reply-To: <20190905121101.60c78422@oasis.local.home> (Steven Rostedt's message of "Thu, 5 Sep 2019 12:11:01 -0400") Message-ID: <87ef0u4fg5.fsf@linutronix.de> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019-09-05, Steven Rostedt wrote: >>> But per the above argument of needing the CPU serialization >>> _anyway_, I don't see a compelling reason not to use it. >>> >>> It is simple, it works. Let's use it. >>> >>> If you really fancy a multi-writer buffer, you can always switch to >>> one later, if you can convince someone it actually brings benefits >>> and not just head-aches. >> >> Can we please grab one of the TBD slots at kernel summit next week, >> sit down in a room and hash that out? >> > > We should definitely be able to find a room that will be available > next week. FWIW, on Monday at 12:45 I am giving a talk[0] on the printk rework. I'll be dedicating a few slides to presenting the lockless multi-writer design, but will also talk about the serialized CPU approach from RFCv1. John Ogness [0] https://www.linuxplumbersconf.org/event/4/contributions/290/