Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753703Ab1FEPe5 (ORCPT ); Sun, 5 Jun 2011 11:34:57 -0400 Received: from mo-p00-ob.rzone.de ([81.169.146.160]:58218 "EHLO mo-p00-ob.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750995Ab1FEPe4 (ORCPT ); Sun, 5 Jun 2011 11:34:56 -0400 X-RZG-AUTH: :IGUXYVOIf/Z0yAghYbpIhzghmj8icP68r1arC3zTx2B9G7/X5zri/u5Y1+fsZ6BmRA== X-RZG-CLASS-ID: mo00 Message-ID: <4DEBA216.1080903@die-jansens.de> Date: Sun, 05 Jun 2011 17:34:46 +0200 From: Arne Jansen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.17) Gecko/20110424 Thunderbird/3.1.10 MIME-Version: 1.0 To: Ingo Molnar 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 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> <20110605151323.GA30590@elte.hu> In-Reply-To: <20110605151323.GA30590@elte.hu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1398 Lines: 47 On 05.06.2011 17:13, Ingo Molnar wrote: > > * 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? yes. > > 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/ -- 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/