Return-Path: <linux-kernel-owner+w=401wt.eu-S1757307AbZAGNUr@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1757307AbZAGNUr (ORCPT <rfc822;w@1wt.eu>);
	Wed, 7 Jan 2009 08:20:47 -0500
Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752359AbZAGNUi
	(ORCPT <rfc822;linux-kernel-outgoing>);
	Wed, 7 Jan 2009 08:20:38 -0500
Received: from viefep17-int.chello.at ([62.179.121.37]:15848 "EHLO
	viefep18-int.chello.at" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org
	with ESMTP id S1751562AbZAGNUh (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Wed, 7 Jan 2009 08:20:37 -0500
X-SourceIP: 213.46.9.244
Subject: Re: [BUG] 2.6.28-git LOCKDEP: Possible recursive rq->lock
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: svaidy@linux.vnet.ibm.com
Cc: Ingo Molnar <mingo@elte.hu>, Linux Kernel <linux-kernel@vger.kernel.org>,
       Balbir Singh <balbir@linux.vnet.ibm.com>,
       Andrew Morton <akpm@linux-foundation.org>,
       Mike Galbraith <efault@gmx.de>
In-Reply-To: <20090107122913.GL4574@dirshya.in.ibm.com>
References: <20090104174450.GB4301@dirshya.in.ibm.com>
	 <1231092523.29980.4.camel@twins> <20090105040635.GF4301@dirshya.in.ibm.com>
	 <20090105130638.GB6014@elte.hu> <20090107114947.GJ4574@dirshya.in.ibm.com>
	 <20090107122913.GL4574@dirshya.in.ibm.com>
Content-Type: text/plain
Date: Wed, 07 Jan 2009 14:12:43 +0100
Message-Id: <1231333963.11687.288.camel@twins>
Mime-Version: 1.0
X-Mailer: Evolution 2.24.2 
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
Content-Length: 1502
Lines: 39

On Wed, 2009-01-07 at 17:59 +0530, Vaidyanathan Srinivasan wrote:

> =============================================
> [ INFO: possible recursive locking detected ]
> 2.6.28-autotest-tip-sv #1
> ---------------------------------------------
> klogd/5062 is trying to acquire lock:
>  (&rq->lock){++..}, at: [<ffffffff8022aca2>] task_rq_lock+0x45/0x7e
> 
> but task is already holding lock:
>  (&rq->lock){++..}, at: [<ffffffff805f7354>] schedule+0x158/0xa31
> 
> other info that might help us debug this:
> 1 lock held by klogd/5062:
>  #0:  (&rq->lock){++..}, at: [<ffffffff805f7354>] schedule+0x158/0xa31
> 
> stack backtrace:
> Pid: 5062, comm: klogd Not tainted 2.6.28-autotest-tip-sv #1
> Call Trace:
>  [<ffffffff80259ef1>] __lock_acquire+0xeb9/0x16a4
>  [<ffffffff8025a6c0>] ? __lock_acquire+0x1688/0x16a4
>  [<ffffffff8025a761>] lock_acquire+0x85/0xa9
>  [<ffffffff8022aca2>] ? task_rq_lock+0x45/0x7e
>  [<ffffffff805fa4d4>] _spin_lock+0x31/0x66
>  [<ffffffff8022aca2>] ? task_rq_lock+0x45/0x7e
>  [<ffffffff8022aca2>] task_rq_lock+0x45/0x7e
>  [<ffffffff80233363>] try_to_wake_up+0x88/0x27a
>  [<ffffffff80233581>] wake_up_process+0x10/0x12
>  [<ffffffff805f775c>] schedule+0x560/0xa31

I'd be most curious to know where in schedule we are.

Thanks

--
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/