Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756048AbZGHVFe (ORCPT ); Wed, 8 Jul 2009 17:05:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754584AbZGHVF0 (ORCPT ); Wed, 8 Jul 2009 17:05:26 -0400 Received: from tomts13.bellnexxia.net ([209.226.175.34]:59247 "EHLO tomts13-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754551AbZGHVFZ (ORCPT ); Wed, 8 Jul 2009 17:05:25 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AjkFAHGiVEpMQWU3/2dsb2JhbACBUdAghAgF Date: Wed, 8 Jul 2009 17:05:22 -0400 From: Mathieu Desnoyers To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton , Thomas Gleixner , Peter Zijlstra , Frederic Weisbecker , Steven Rostedt , "Paul E. McKenney" Subject: Re: [PATCH 2/3] ring-buffer: make lockless Message-ID: <20090708210522.GA17430@Krystal> References: <20090708201312.222046866@goodmis.org> <20090708201445.696220393@goodmis.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <20090708201445.696220393@goodmis.org> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 16:22:28 up 130 days, 16:48, 4 users, load average: 0.89, 0.98, 0.77 User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1110 Lines: 29 * Steven Rostedt (rostedt@goodmis.org) wrote: > From: Steven Rostedt > > This patch converts the ring buffers into a completely lockless > buffer recording system. The read side still takes locks since > we still serialize readers. But the writers are the ones that > must be lockless (those can happen in NMIs). Hi Steven, Have you started modeling this scheme with Promela as I previously discussed with you ? Paul McKenney did a lot of nice papers on the topic, and given the complexity level of this lockless buffering algorithm, I'd be much more comfortable if it was formally verified. The idea here is to make sure we don't start an endless bug-chasing hunt as trace buffers gets more exposure to various workloads. Thanks, Mathieu -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/