Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753892AbZAGM0f (ORCPT ); Wed, 7 Jan 2009 07:26:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752029AbZAGM0W (ORCPT ); Wed, 7 Jan 2009 07:26:22 -0500 Received: from e28smtp08.in.ibm.com ([59.145.155.8]:54053 "EHLO e28smtp08.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752371AbZAGM0V (ORCPT ); Wed, 7 Jan 2009 07:26:21 -0500 Date: Wed, 7 Jan 2009 17:59:13 +0530 From: Vaidyanathan Srinivasan To: Ingo Molnar Cc: Peter Zijlstra , Linux Kernel , Balbir Singh , Andrew Morton , Mike Galbraith Subject: Re: [BUG] 2.6.28-git LOCKDEP: Possible recursive rq->lock Message-ID: <20090107122913.GL4574@dirshya.in.ibm.com> Reply-To: svaidy@linux.vnet.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> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20090107114947.GJ4574@dirshya.in.ibm.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3706 Lines: 99 * Vaidyanathan Srinivasan [2009-01-07 17:19:47]: > * Ingo Molnar [2009-01-05 14:06:38]: > > > > > * Vaidyanathan Srinivasan wrote: > > > > > * Peter Zijlstra [2009-01-04 19:08:43]: > > > > > > > On Sun, 2009-01-04 at 23:14 +0530, Vaidyanathan Srinivasan wrote: > > > > > Hi Ingo, > > > > > > > > > > Kernbench runs on latest Linux git tree stalled with the following > > > > > lockdep warning. > > > > > > > > > > Lockdep warning and lockup on Jan 3 Linus git tree > > > > > commit 7d3b56ba37a95f1f370f50258ed3954c304c524b > > > > > > > > > > kernbench run with two threads stalled. sched_mc was zero. > > > > > x86_64 system with 8 logical CPUs in dual socket quad core > > > > > configuration. > > > > > > > > > > I will post more information as I debug this warning/bug. > > > > > > > > Its ca109491f612aab5c8152207631c0444f63da97f, I've some ideas on how to > > > > fix this, just haven't gotten around to actually doing anything -- > > > > seeing how it was holidays and such.. > > > > > > Hi Peter, > > > > > > I can definitely test your fix when you have them. I have an > > > autotest job that hits this bug. > > > > could you check latest tip/master, it has Peter's and Thomas's hrtimer > > fixes. > > Hi Peter, > > I still get the following warning at the first kernel build (kernbench > run) but the entire tests complete without any lockups. > > Please let me know if these make sense. I have CONFIG_FRAME_POINTER=y > in these runs. > > Test run on sched-tip on Jan 5 at commit 4c1ae1dfea7a5fcab3444220a38054dd50c08441 Another one... ============================================= [ INFO: possible recursive locking detected ] 2.6.28-autotest-tip-sv #1 --------------------------------------------- klogd/5062 is trying to acquire lock: (&rq->lock){++..}, at: [] task_rq_lock+0x45/0x7e but task is already holding lock: (&rq->lock){++..}, at: [] schedule+0x158/0xa31 other info that might help us debug this: 1 lock held by klogd/5062: #0: (&rq->lock){++..}, at: [] schedule+0x158/0xa31 stack backtrace: Pid: 5062, comm: klogd Not tainted 2.6.28-autotest-tip-sv #1 Call Trace: [] __lock_acquire+0xeb9/0x16a4 [] ? __lock_acquire+0x1688/0x16a4 [] lock_acquire+0x85/0xa9 [] ? task_rq_lock+0x45/0x7e [] _spin_lock+0x31/0x66 [] ? task_rq_lock+0x45/0x7e [] task_rq_lock+0x45/0x7e [] try_to_wake_up+0x88/0x27a [] wake_up_process+0x10/0x12 [] schedule+0x560/0xa31 [] schedule_timeout+0x22/0xb4 [] ? _spin_unlock+0x26/0x2a [] unix_wait_for_peer+0x9c/0xbb [] ? autoremove_wake_function+0x0/0x38 [] ? _spin_lock+0x5d/0x66 [] unix_dgram_sendmsg+0x3a8/0x4a3 [] sock_aio_write+0x107/0x117 [] do_sync_write+0xe7/0x12d [] ? cp_new_stat+0xe2/0xef [] ? autoremove_wake_function+0x0/0x38 [] vfs_write+0xc1/0x137 [] sys_write+0x47/0x70 [] system_call_fastpath+0x16/0x1b I have debug info enabled, I can lookup any address you would like. --Vaidy -- 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/