From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758865AbZADRmO (ORCPT ); Sun, 4 Jan 2009 12:42:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755354AbZADRmE (ORCPT ); Sun, 4 Jan 2009 12:42:04 -0500 Received: from e28smtp05.in.ibm.com ([59.145.155.5]:38477 "EHLO e28smtp05.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752196AbZADRmB (ORCPT ); Sun, 4 Jan 2009 12:42:01 -0500 Date: Sun, 4 Jan 2009 23:14:50 +0530 From: Vaidyanathan Srinivasan To: Linux Kernel Cc: Ingo Molnar , Peter Zijlstra , Balbir Singh , Andrew Morton , Mike Galbraith Subject: [BUG] 2.6.28-git LOCKDEP: Possible recursive rq->lock Message-ID: <20090104174450.GB4301@dirshya.in.ibm.com> Reply-To: svaidy@linux.vnet.ibm.com MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline 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 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. --Vaidy kernel: ============================================= kernel: [ INFO: possible recursive locking detected ] kernel: 2.6.28-autotest-sv #1 kernel: --------------------------------------------- kernel: autotest/6230 is trying to acquire lock: kernel: (&rq->lock){++..}, at: [] task_rq_lock+0x44/0x7e kernel: kernel: but task is already holding lock: kernel: (&rq->lock){++..}, at: [] schedule+0x144/0x9d6 kernel: kernel: other info that might help us debug this: kernel: 1 lock held by autotest/6230: kernel: #0: (&rq->lock){++..}, at: [] schedule+0x144/0x9d6 kernel: kernel: stack backtrace: kernel: Pid: 6230, comm: autotest Not tainted 2.6.28-autotest-sv #1 kernel: Call Trace: kernel: [] __lock_acquire+0xe2a/0x15ed kernel: [] lock_acquire+0x85/0xa9 kernel: [] task_rq_lock+0x44/0x7e kernel: [] _spin_lock+0x2d/0x5f kernel: [] task_rq_lock+0x44/0x7e kernel: [] task_rq_lock+0x44/0x7e kernel: [] try_to_wake_up+0x83/0x26f kernel: [] schedule+0x144/0x9d6 kernel: [] schedule+0x558/0x9d6 kernel: [] trace_hardirqs_on_caller+0x120/0x14a kernel: [] hrtimer_start_range_ns+0x143/0x156 kernel: [] schedule_hrtimeout_range+0xcc/0xff kernel: [] hrtimer_wakeup+0x0/0x22 kernel: [] schedule_hrtimeout_range+0xae/0xff kernel: [] do_select+0x502/0x55d kernel: [] do_select+0x0/0x55d kernel: [] __pollwait+0x0/0xe5 kernel: [] default_wake_function+0x0/0x9 kernel: [] default_wake_function+0x0/0x9 kernel: [] __lock_acquire+0x15d4/0x15ed last message repeated 2 times kernel: [] lock_release_holdtime+0x1b/0x16c kernel: [] lock_release_holdtime+0x1b/0x16c kernel: [] core_sys_select+0x31/0x2b0 kernel: [] core_sys_select+0x1ec/0x2b0 kernel: [] core_sys_select+0x31/0x2b0 kernel: [] remove_wait_queue+0x12/0x41 kernel: [] lock_release_holdtime+0x1b/0x16c kernel: [] _spin_unlock_irqrestore+0x3e/0x44 kernel: [] trace_hardirqs_on_caller+0x120/0x14a kernel: [] do_wait+0x2a4/0x395 kernel: [] getnstimeofday+0x38/0x92 kernel: [] sys_select+0x92/0xbb kernel: [] system_call_fastpath+0x16/0x1b