From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx189.postini.com [74.125.245.189]) by kanga.kvack.org (Postfix) with SMTP id E7F146B0068 for ; Wed, 17 Oct 2012 17:53:45 -0400 (EDT) Date: Wed, 17 Oct 2012 23:53:38 +0200 From: Andrea Righi Subject: mm/mmu_notifier: inconsistent lock state in mmu_notifier_register() Message-ID: <20121017215338.GA3577@thinkpad> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli Cc: Christoph Lameter , Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Just got this on 3.7.0-rc1 (last git commit 1867353): [49048.262912] ================================= [49048.262913] [ INFO: inconsistent lock state ] [49048.262916] 3.7.0-rc1+ #518 Not tainted [49048.262918] --------------------------------- [49048.262919] inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage. [49048.262922] kswapd0/35 [HC0[0]:SC0[0]:HE1:SE1] takes: [49048.262924] (&mapping->i_mmap_mutex){+.+.?.}, at: [] page_referenced+0x9c/0x2e0 [49048.262933] {RECLAIM_FS-ON-W} state was registered at: [49048.262935] [] mark_held_locks+0x86/0x150 [49048.262938] [] lockdep_trace_alloc+0x67/0xc0 [49048.262942] [] kmem_cache_alloc_trace+0x33/0x230 [49048.262945] [] do_mmu_notifier_register+0x87/0x180 [49048.262948] [] mmu_notifier_register+0x13/0x20 [49048.262951] [] kvm_dev_ioctl+0x428/0x510 [49048.262955] [] do_vfs_ioctl+0x98/0x570 [49048.262959] [] sys_ioctl+0x91/0xb0 [49048.262962] [] system_call_fastpath+0x16/0x1b [49048.262966] irq event stamp: 825 [49048.262968] hardirqs last enabled at (825): [] _raw_spin_unlock_irq+0x30/0x60 [49048.262971] hardirqs last disabled at (824): [] _raw_spin_lock_irq+0x19/0x80 [49048.262975] softirqs last enabled at (0): [] copy_process+0x630/0x17c0 [49048.262979] softirqs last disabled at (0): [< (null)>] (null) [49048.262981] [49048.262981] other info that might help us debug this: [49048.262983] Possible unsafe locking scenario: [49048.262983] [49048.262984] CPU0 [49048.262986] ---- [49048.262987] lock(&mapping->i_mmap_mutex); [49048.262989] [49048.262991] lock(&mapping->i_mmap_mutex); [49048.262993] [49048.262993] *** DEADLOCK *** [49048.262993] [49048.262995] no locks held by kswapd0/35. [49048.262996] [49048.262996] stack backtrace: [49048.262999] Pid: 35, comm: kswapd0 Not tainted 3.7.0-rc1+ #518 [49048.263000] Call Trace: [49048.263005] [] print_usage_bug+0x1f5/0x206 [49048.263008] [] ? save_stack_trace+0x2f/0x50 [49048.263011] [] mark_lock+0x295/0x2f0 [49048.263014] [] ? print_irq_inversion_bug.part.42+0x1f0/0x1f0 [49048.263017] [] __lock_acquire+0x59d/0x1c20 [49048.263020] [] ? put_cpu_partial+0x65/0xbd [49048.263024] [] ? native_sched_clock+0x26/0x90 [49048.263028] [] ? sched_clock_cpu+0xc5/0x120 [49048.263031] [] lock_acquire+0x90/0x210 [49048.263034] [] ? page_referenced+0x9c/0x2e0 [49048.263038] [] mutex_lock_nested+0x73/0x3d0 [49048.263041] [] ? page_referenced+0x9c/0x2e0 [49048.263044] [] ? page_referenced+0x9c/0x2e0 [49048.263047] [] ? put_lock_stats.isra.26+0xe/0x40 [49048.263051] [] ? lock_release_holdtime.part.27+0xd4/0x150 [49048.263055] [] ? __remove_mapping+0xab/0x120 [49048.263058] [] page_referenced+0x9c/0x2e0 [49048.263061] [] shrink_page_list+0x3e4/0xa20 [49048.263064] [] ? native_sched_clock+0x26/0x90 [49048.263068] [] ? shrink_inactive_list+0x165/0x4b0 [49048.263071] [] ? _raw_spin_unlock_irq+0x30/0x60 [49048.263075] [] shrink_inactive_list+0x1f7/0x4b0 [49048.263079] [] shrink_lruvec+0x44d/0x550 [49048.263082] [] kswapd+0x703/0xdf0 [49048.263086] [] ? __init_waitqueue_head+0x60/0x60 [49048.263090] [] ? shrink_lruvec+0x550/0x550 [49048.263093] [] kthread+0xed/0x100 [49048.263097] [] ? flush_kthread_worker+0x190/0x190 [49048.263100] [] ret_from_fork+0x7c/0xb0 [49048.263103] [] ? flush_kthread_worker+0x190/0x190 Should we use a GFP_NOFS allocation in mmu_notifier_register() or is there a better way to fix/avoid this? Thanks, -Andrea -- 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