Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755355AbZGHRXN (ORCPT ); Wed, 8 Jul 2009 13:23:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754100AbZGHRW7 (ORCPT ); Wed, 8 Jul 2009 13:22:59 -0400 Received: from mx2.redhat.com ([66.187.237.31]:55920 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754075AbZGHRW7 (ORCPT ); Wed, 8 Jul 2009 13:22:59 -0400 Date: Wed, 8 Jul 2009 13:22:48 -0400 From: Dave Jones To: Peter Zijlstra Cc: Joao Correia , LKML , =?iso-8859-1?Q?Am=E9rico?= Wang Subject: Re: [PATCH 1/3] Increase lockdep limits: MAX_STACK_TRACE_ENTRIES Message-ID: <20090708172248.GB2521@redhat.com> Mail-Followup-To: Dave Jones , Peter Zijlstra , Joao Correia , LKML , =?iso-8859-1?Q?Am=E9rico?= Wang References: <1246980836.9777.5.camel@twins> <1246981444.9777.11.camel@twins> <1246982101.9777.15.camel@twins> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1246982101.9777.15.camel@twins> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2663 Lines: 63 On Tue, Jul 07, 2009 at 05:55:01PM +0200, Peter Zijlstra wrote: > On Tue, 2009-07-07 at 16:50 +0100, Joao Correia wrote: > > > >> Yes. Anything 2.6.31 forward triggers this immediatly during init > > >> process, at random places. > > > > > > Not on my machines it doesn't.. so I suspect its something weird in > > > your .config or maybe due to some hardware you have that I don't that > > > triggers different drivers or somesuch. > > > > I am not the only one reporting this, and it happens, for example, > > with a stock .config from a Fedora 11 install. > > > > It may, of course, be a funny driver interaction yes, but other than > > stripping the box piece by piece, how would one go about debugging > > this otherwise? > > One thing to do is stare (or share) at the output > of /proc/lockdep_chains and see if there's some particularly large > chains in there, or many of the same name or something. I don't see any long chains, just lots of them. 29065 lines on my box that's hitting MAX_STACK_TRACE_ENTRIES > /proc/lockdep_stats might also be interesting, mine reads like: lock-classes: 1518 [max: 8191] direct dependencies: 7142 [max: 16384] indirect dependencies: 97905 all direct dependencies: 753706 dependency chains: 6201 [max: 32768] dependency chain hlocks: 16665 [max: 163840] in-hardirq chains: 1380 in-softirq chains: 589 in-process chains: 4232 stack-trace entries: 262144 [max: 262144] combined max dependencies: 3449006070 hardirq-safe locks: 1008 hardirq-unsafe locks: 364 softirq-safe locks: 838 softirq-unsafe locks: 322 irq-safe locks: 1043 irq-unsafe locks: 364 hardirq-read-safe locks: 0 hardirq-read-unsafe locks: 48 softirq-read-safe locks: 0 softirq-read-unsafe locks: 48 irq-read-safe locks: 0 irq-read-unsafe locks: 48 uncategorized locks: 104 unused locks: 0 max locking depth: 9 max recursion depth: 10 debug_locks: 0 Dave -- 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/