From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754263Ab0C3PF4 (ORCPT ); Tue, 30 Mar 2010 11:05:56 -0400 Received: from mail.openrapids.net ([64.15.138.104]:48268 "EHLO blackscsi.openrapids.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751813Ab0C3PFy (ORCPT ); Tue, 30 Mar 2010 11:05:54 -0400 Date: Tue, 30 Mar 2010 11:05:51 -0400 From: Mathieu Desnoyers To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, Randy Dunlap , Eric Dumazet , Rusty Russell , Tejun Heo , Ingo Molnar , Andrew Morton , Linus Torvalds , Greg Kroah-Hartman , Steven Rostedt , stable Subject: Re: [PATCH] lockdep fix incorrect percpu usage Message-ID: <20100330150551.GA22312@Krystal> References: <20100330033425.GD7683@Krystal> <1269938876.5109.510.camel@twins> <20100330134555.GA20673@Krystal> <1269959111.5258.142.camel@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1269959111.5258.142.camel@laptop> X-Editor: vi X-Info: http://www.efficios.com X-Operating-System: Linux/2.6.26-2-686 (i686) X-Uptime: 11:03:39 up 66 days, 17:40, 9 users, load average: 0.90, 0.71, 0.73 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 * Peter Zijlstra (peterz@infradead.org) wrote: > On Tue, 2010-03-30 at 09:45 -0400, Mathieu Desnoyers wrote: > > * Peter Zijlstra (peterz@infradead.org) wrote: > > > On Mon, 2010-03-29 at 23:34 -0400, Mathieu Desnoyers wrote: > > > > Should use per_cpu_ptr() to obfuscate the per cpu pointers (RELOC_HIDE is needed > > > > for per cpu pointers). > > > > > > > > git blame points to commit: > > > > > > > > lockdep.c: commit 8e18257d29238311e82085152741f0c3aa18b74d > > > > > > > > But it's really just moving the code around. But it's enough to say that the > > > > problems appeared before Jul 19 01:48:54 2007, which brings us back to 2.6.23. > > > > > > > > So it should be applied to stable 2.6.23.x to 2.6.33.x (or whichever of these > > > > stable branches are still maintained) and to mainline 2.6.34-rc2. > > > > > > well, definately not to mainline, since that code is utterly busted in > > > mainline due to recent per-cpu changes. > > > > How recent ? I'm based on > > > > commit f57d4e859a8acd63f878cd0534ec4b990b1710dc > > Merge: 0528faa... eed6351... > > Author: Ingo Molnar > > Date: Mon Mar 29 18:56:00 2010 +0200 > > > > from -tip and I see the problem there, both in module.c and lockdep.c. > > Yeah, its basically been busted since the early merge window period, > hopefully Tejun's patches will make it in soon: > > http://lkml.org/lkml/2010/3/10/79 I see. These patches are "on their way" to mainline, so it's better not to create conflicts. So the lockdep patch should only be applied to -stable, but separate module.c patch should apply to both -stable and mainline. Am I correct ? Thanks, Mathieu > > > -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com