Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750985AbWJRHUy (ORCPT ); Wed, 18 Oct 2006 03:20:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751144AbWJRHUx (ORCPT ); Wed, 18 Oct 2006 03:20:53 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:7071 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S1751114AbWJRHUv (ORCPT ); Wed, 18 Oct 2006 03:20:51 -0400 Date: Wed, 18 Oct 2006 09:12:58 +0200 From: Ingo Molnar To: Dipankar Sarma Cc: Karsten Wiese , Lee Revell , linux-kernel@vger.kernel.org, Thomas Gleixner , John Stultz , "Paul E. McKenney" , Arjan van de Ven Subject: Re: 2.6.18-rt1 Message-ID: <20061018071258.GA27949@elte.hu> References: <20060920141907.GA30765@elte.hu> <1159639564.4067.43.camel@mindpipe> <20060930181804.GA28768@in.ibm.com> <200610132318.02512.annabellesgarden@yahoo.de> <20061013212450.GC7477@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061013212450.GC7477@in.ibm.com> User-Agent: Mutt/1.4.2.2i X-ELTE-SpamScore: -2.8 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.8 required=5.9 tests=ALL_TRUSTED,AWL,BAYES_50 autolearn=no SpamAssassin version=3.0.3 -3.3 ALL_TRUSTED Did not pass through any untrusted hosts 0.5 BAYES_50 BODY: Bayesian spam probability is 40 to 60% [score: 0.5000] -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: 1785 Lines: 54 * Dipankar Sarma wrote: > Sorry, I should have published my investigations long ago. I tracked > this down (atleast the crash in my machine) to NMI interference with > rcu_read_lock()/rcu_read_unlock(). We use those APIs from NMI context > as well > (default_do_nmi()->notify_die()->atomic_notifier_call_chain()). > > Can you try with nmi_watchdog=0 in the kernel command line ? > > Paul has an NMI-safe patch for rcupreempt which I am adopting and > testing at the moment. If this works well, I will publish a new > patchset. spent some good time debugging this 2 weeks ago and added the fix below to rt5, but i forgot to do the symmetric fix for x86_64... Ingo -----------> arch/i386/kernel/traps.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) Index: linux/arch/i386/kernel/traps.c =================================================================== --- linux.orig/arch/i386/kernel/traps.c +++ linux/arch/i386/kernel/traps.c @@ -716,9 +716,6 @@ static void default_do_nmi(struct pt_reg reason = get_nmi_reason(); if (!(reason & 0xc0)) { - if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT) - == NOTIFY_STOP) - return; #ifdef CONFIG_X86_LOCAL_APIC /* * Ok, so this is none of the documented NMI sources, @@ -729,6 +726,9 @@ static void default_do_nmi(struct pt_reg return; } #endif + if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT) + == NOTIFY_STOP) + return; unknown_nmi_error(reason, regs); return; } - 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/