From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id D3BDE6B01E3 for ; Wed, 14 Apr 2010 16:23:56 -0400 (EDT) Received: from d01relay05.pok.ibm.com (d01relay05.pok.ibm.com [9.56.227.237]) by e6.ny.us.ibm.com (8.14.3/8.13.1) with ESMTP id o3EKLOmM027666 for ; Wed, 14 Apr 2010 16:21:24 -0400 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay05.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id o3EKNo1w162932 for ; Wed, 14 Apr 2010 16:23:50 -0400 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.14.3/8.13.1/NCO v10.0 AVout) with ESMTP id o3EKNmIM013465 for ; Wed, 14 Apr 2010 16:23:49 -0400 Date: Wed, 14 Apr 2010 13:23:47 -0700 From: "Paul E. McKenney" Subject: Lockdep splat in cpuset code acquiring alloc_lock Message-ID: <20100414202347.GA26791@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: owner-linux-mm@kvack.org To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, containers@lists.linux-foundation.org Cc: balbir@linux.vnet.ibm.com, menage@google.com, lizf@cn.fujitsu.com List-ID: Hello! I hit the following lockdep splat on one of many runs. Thoughts? Thanx, Paul ------------------------------------------------------------------------ ================================= [ INFO: inconsistent lock state ] 2.6.34-rc3-autokern1 #1 --------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/0 [HC0[0]:SC1[1]:HE0:SE0] takes: (&(&p->alloc_lock)->rlock){+.?...}, at: [] .cpuset_cpus_allowed_locked+0x2c/0xbc {SOFTIRQ-ON-W} state was registered at: [] .lock_acquire+0x5c/0x88 [] ._raw_spin_lock+0x48/0x70 [] .set_task_comm+0x34/0x9c [] .kthreadd+0x30/0x160 [] .kernel_thread+0x54/0x70 irq event stamp: 782497 hardirqs last enabled at (782496): [] ._raw_spin_unlock_irq+0x38/0x80 hardirqs last disabled at (782497): [] .task_rq_lock+0x74/0x130 softirqs last enabled at (782478): [] .call_do_softirq+0x14/0x24 softirqs last disabled at (782493): [] .call_do_softirq+0x14/0x24 other info that might help us debug this: 2 locks held by swapper/0: #0: (&timer){+.-.-.}, at: [] .run_timer_softirq+0x138/0x298 #1: (rcu_read_lock){.+.+..}, at: [] .select_fallback_rq+0xe8/0x1c4 stack backtrace: Call Trace: [c00000000ffff740] [c000000000010168] .show_stack+0x70/0x184 (unreliable) [c00000000ffff7f0] [c0000000000933b8] .print_usage_bug+0x1d4/0x208 [c00000000ffff8b0] [c000000000093778] .mark_lock+0x38c/0x6f4 [c00000000ffff960] [c00000000009696c] .__lock_acquire+0x6ac/0x96c [c00000000ffffa60] [c000000000097ca8] .lock_acquire+0x5c/0x88 [c00000000ffffb00] [c000000000570270] ._raw_spin_lock+0x48/0x70 [c00000000ffffb90] [c0000000000affd4] .cpuset_cpus_allowed_locked+0x2c/0xbc [c00000000ffffc20] [c0000000000541bc] .select_fallback_rq+0x124/0x1c4 [c00000000ffffcd0] [c00000000005ee44] .try_to_wake_up+0x1ac/0x3b4 [c00000000ffffd80] [c000000000071910] .process_timeout+0x10/0x24 [c00000000ffffdf0] [c000000000071348] .run_timer_softirq+0x1e0/0x298 [c00000000ffffed0] [c00000000006a440] .__do_softirq+0x158/0x254 [c00000000fffff90] [c000000000026acc] .call_do_softirq+0x14/0x24 [c00000000095b8f0] [c00000000000cd34] .do_softirq+0xb0/0x138 [c00000000095b990] [c00000000006a680] .irq_exit+0x88/0x100 [c00000000095ba20] [c0000000000243a8] .timer_interrupt+0x150/0x19c [c00000000095bad0] [c000000000003704] decrementer_common+0x104/0x180 --- Exception: 901 at .raw_local_irq_restore+0x6c/0x80 LR = .cpu_idle+0x138/0x20c [c00000000095bdc0] [0000000000253400] 0x253400 (unreliable) [c00000000095be40] [c0000000000129e8] .cpu_idle+0x138/0x20c [c00000000095bed0] [c00000000057a844] .start_secondary+0x3c4/0x404 [c00000000095bf90] [c000000000008264] .start_secondary_prolog+0x10/0x14 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org