Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932445AbWE3UEu (ORCPT ); Tue, 30 May 2006 16:04:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932457AbWE3UEu (ORCPT ); Tue, 30 May 2006 16:04:50 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:11199 "EHLO mx3.mail.elte.hu") by vger.kernel.org with ESMTP id S932445AbWE3UEt (ORCPT ); Tue, 30 May 2006 16:04:49 -0400 Date: Tue, 30 May 2006 22:05:09 +0200 From: Ingo Molnar To: Andi Kleen Cc: Andrew Morton , linux-kernel@vger.kernel.org, Arjan van de Ven Subject: Re: [patch, -rc5-mm1] lock validator: disable NMI watchdog if CONFIG_LOCKDEP, i386 Message-ID: <20060530200509.GA24928@elte.hu> References: <20060530111138.GA5078@elte.hu> <1148990326.7599.4.camel@homer> <1148990725.8610.1.camel@homer> <20060530120641.GA8263@elte.hu> <1148991422.8610.8.camel@homer> <20060530121952.GA9625@elte.hu> <1148992098.8700.2.camel@homer> <20060530122950.GA10216@elte.hu> <20060530194748.GC22742@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060530194748.GC22742@elte.hu> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=AWL autolearn=no SpamAssassin version=3.0.3 0.0 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 750 Lines: 20 * Ingo Molnar wrote: > yeah, totally agreed, they need to be raw notifiers. Havent had time > to investigate it in detail yet - i went for the easier hack of > disabling NMIs while lockdep is enabled. hm ... atomic_notifier_call_chain ought to be fine - it uses rcu_read_lock(), which uses preempt_disable(), which is NMI-safe. so i think this NMI problem might be lockdep-specific. I think it might be the NMI iret that confuses lockdep. (and irqflags-trace in particular) Ingo - 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/