Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756665Ab0DNUXy (ORCPT ); Wed, 14 Apr 2010 16:23:54 -0400 Received: from e1.ny.us.ibm.com ([32.97.182.141]:57749 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755619Ab0DNUXw (ORCPT ); Wed, 14 Apr 2010 16:23:52 -0400 Date: Wed, 14 Apr 2010 13:23:47 -0700 From: "Paul E. McKenney" 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 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 User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3110 Lines: 62 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 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/