From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754039AbZD2HWh (ORCPT ); Wed, 29 Apr 2009 03:22:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752154AbZD2HW2 (ORCPT ); Wed, 29 Apr 2009 03:22:28 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:55500 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750834AbZD2HW1 (ORCPT ); Wed, 29 Apr 2009 03:22:27 -0400 Date: Wed, 29 Apr 2009 09:22:08 +0200 From: Ingo Molnar To: Andrew Morton Cc: Stephen Rothwell , Steven Rostedt , linux-kernel@vger.kernel.org, Frederic Weisbecker Subject: Re: [PATCH 5/5] ring-buffer: fix printk output Message-ID: <20090429072208.GA22129@elte.hu> References: <20090429044814.138790038@goodmis.org> <20090429045908.394874083@goodmis.org> <20090428222024.8db50539.akpm@linux-foundation.org> <20090429054359.GA6148@elte.hu> <20090428225541.9ca61a12.akpm@linux-foundation.org> <20090429060955.GD6148@elte.hu> <20090428232000.6c3d4ce1.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090428232000.6c3d4ce1.akpm@linux-foundation.org> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Andrew Morton wrote: > On Wed, 29 Apr 2009 08:09:55 +0200 Ingo Molnar wrote: > > > > > * Andrew Morton wrote: > > > > > On Wed, 29 Apr 2009 07:43:59 +0200 Ingo Molnar wrote: > > > > > > > > > > > * Andrew Morton wrote: > > > > > > > > > On Wed, 29 Apr 2009 00:48:19 -0400 Steven Rostedt wrote: > > > > > > > > > > > - printk_once(KERN_WARNING "Tracing recursion: depth[%d]:" > > > > > > + printk_once(KERN_WARNING "Tracing recursion: depth[%ld]:" > > > > > > > > > > hrmph. I didn't know that printk_once() existed, and I should > > > > > have known. I wonder how many other people don't know. > > > > > > > > Was posted to linux-next@vger.kernel.org. > > > > > > Well no wonder I didn't know about it. > > > > I (too?) think it's counter-productive that the linux-next list is > > split out of lkml. I constantly fall into that trap: i get a > > bugreport against one of our trees, i see that there's vger in the > > Cc: list and mistake it for being Cc:-ed to lkml (all our trees are > > developed on lkml and most of the bugreports come Cc:-ed to lkml) > > but in reality it's Cc:-ed to linux-next which has a much smaller > > audience. (which audience apparently does not even include you) > > > > If this email list fragmentation and the resoluting loss of > > information bothers you too then please ask Stephen to move > > linux-next mails to lkml (i've Cc:-ed Stephen) - it's not like it's > > actually something separate ... today's linux-next messages are > > tomorrow's lkml messages. Moving linux-next mails to lkml would > > nicely improve the S/N ratio on lkml. > > > > eh. Just auto-add lkml to tipbot-commit emails? Yeah - the tip-commits-bot already has such a feature and we are making use of it - but this commit predates it. So it was posted to linux-next and the tip-commits list. My larger point remains, about possibly embedding linux-next into lkml. I couldnt think of a single linux-next mail that isnt relevant to lkml. It's all about commits that are destined for upstream in 0-2.5 months. > printk_once() is racy on smp and preempt btw ;) Like WARN_ONCE() and WARN_ON_ONCE(). It's really an "oh crap" facility, not for normal kernel messages. Do we want to complicate them with locking and preemption - or should we just concentrate on getting the "oh crap" message out to the syslog (before it's possibly too late to get anything out)? I have no strong opinion about it - but i tend to like the simpler method most. printk + stack dumps themselves arent atomic to begin with. Ingo