From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762219AbZFOPTl (ORCPT ); Mon, 15 Jun 2009 11:19:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756191AbZFOPTd (ORCPT ); Mon, 15 Jun 2009 11:19:33 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:59240 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753811AbZFOPTd (ORCPT ); Mon, 15 Jun 2009 11:19:33 -0400 Date: Mon, 15 Jun 2009 17:19:18 +0200 From: Ingo Molnar To: Alan Cox Cc: Peter Zijlstra , linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] Debug bits for the tty ldisc problem Message-ID: <20090615151918.GA27094@elte.hu> References: <20090615153015.4036.76588.stgit@t61.ukuu.org.uk> <1245076796.6800.488.camel@laptop> <20090615161439.507fb04b@lxorguk.ukuu.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090615161439.507fb04b@lxorguk.ukuu.org.uk> User-Agent: Mutt/1.5.18 (2008-05-17) 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=3.2.5 -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 * Alan Cox wrote: > On Mon, 15 Jun 2009 16:39:56 +0200 > Peter Zijlstra wrote: > > > On Mon, 2009-06-15 at 16:32 +0100, Alan Cox wrote: > > > I'm not 100% sure the close one is > > > safe for locking but as the lock detector has been busted since 2.6.30 its a > > > bit hard to be sure. > > > > Would you have some specifics? > > I stuck it in bugzilla basically it blows up with a > > BUG: MAX_STACK_TRACE_ENTRIES too low! turning off the locking > correctness validator. > > and has done for ages. It's hitting a simple limit. Please try the patch below - it quadruples the value printed in the warning (the number of entries) - does that get your system going? Lock validation is getting more and more popular, covering now a lot more than just locks (workqueues, timers, etc.), so the max number of entries is steadily increasing. Some configs will run into this faster. Ingo diff --git a/kernel/lockdep_internals.h b/kernel/lockdep_internals.h index 699a2ac..031f4c6 100644 --- a/kernel/lockdep_internals.h +++ b/kernel/lockdep_internals.h @@ -65,7 +65,7 @@ enum { * Stack-trace: tightly packed array of stack backtrace * addresses. Protected by the hash_lock. */ -#define MAX_STACK_TRACE_ENTRIES 262144UL +#define MAX_STACK_TRACE_ENTRIES 1048576UL extern struct list_head all_lock_classes; extern struct lock_chain lock_chains[];