Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752133Ab1FEPNo (ORCPT ); Sun, 5 Jun 2011 11:13:44 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:41416 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750957Ab1FEPNn (ORCPT ); Sun, 5 Jun 2011 11:13:43 -0400 Date: Sun, 5 Jun 2011 17:13:23 +0200 From: Ingo Molnar To: Arne Jansen Cc: Peter Zijlstra , Linus Torvalds , mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, efault@gmx.de, npiggin@kernel.dk, akpm@linux-foundation.org, frank.rowand@am.sony.com, tglx@linutronix.de, linux-tip-commits@vger.kernel.org Subject: Re: [debug patch] printk: Add a printk killswitch to robustify NMI watchdog messages Message-ID: <20110605151323.GA30590@elte.hu> References: <20110605095555.GA22058@elte.hu> <4DEB58D8.4000805@die-jansens.de> <20110605110132.GB23463@elte.hu> <20110605111933.GA24592@elte.hu> <20110605113627.GA25724@elte.hu> <4DEB6F3A.3000109@die-jansens.de> <20110605133958.GA27812@elte.hu> <4DEB8A93.30601@die-jansens.de> <20110605141003.GB29338@elte.hu> <4DEB933C.1070900@die-jansens.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4DEB933C.1070900@die-jansens.de> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes 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 Content-Length: 1040 Lines: 37 * Arne Jansen wrote: > sched.c:934: in function __task_rq_lock > lockdep_assert_held(&p->pi_lock); Oh. Could you remove that line with the patch below - does it result in a working system? Now, this patch alone just removes a debugging check - but i'm not sure the debugging check is correct - we take the pi_lock in a raw way - which means it's not lockdep covered. So how can lockdep_assert_held() be called on it? Thanks, Ingo diff --git a/kernel/sched.c b/kernel/sched.c index fd18f39..a32316b 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -938,8 +938,6 @@ static inline struct rq *__task_rq_lock(struct task_struct *p) { struct rq *rq; - lockdep_assert_held(&p->pi_lock); - for (;;) { rq = task_rq(p); raw_spin_lock(&rq->lock); -- 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/