Re: 3.16-rc1 kernel BUG triggered at mutex.c:586
On Mon, 2014-06-16 at 14:28 -0400, Vlad Yasevich wrote: > Trying to boot 3.16.0-rc1+ (the + is a small vlan related patch) on a > tests system triggers the following BUG: It's easier for developers to read if you dump dmesg, or at least tell your mail client to please not make a line-wrapped mess of your report. BUG: sleeping function called from invalid context at kernel/locking/mutex.c:586 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/3 1 lock held by swapper/3/0: #0: (&(>counts.lock)->rlock){..-...}, at: [] bitmap_endwrite+0x58/0x230 211959 hardirqs last enabled at (211958): [] _raw_spin_unlock_irqrestore+0x36/0x70 hardirqs last disabled at (211959): [] _raw_spin_lock_irqsave+0x29/0x70 softirqs last enabled at (211952): [] _local_bh_enable+0x22/0x50 softirqs last disabled at (211953): [] irq_exit+0xc5/0xd0 swapper/3 Not tainted 3.16.0-rc1+ #35 Hewlett-Packard HP xw8400 Workstation/0A08h, BIOS 786D5 v02.38 10/25/2010 88047fcc3bd0 81706ef2 81c857e0 88047fcc3be0 810b4dba 88047fcc3c50 8170c79c 81c85938 0046 0092 Call Trace: [] dump_stack+0x4d/0x66 [] __might_sleep+0xfa/0x130 [] mutex_lock_nested+0x3c/0x3a0 [] kernfs_notify+0x8a/0x140 [] bitmap_endwrite+0xb9/0x230 [] close_write+0x93/0xb0 [raid1] [] r1_bio_write_done+0x29/0x50 [raid1] [] raid1_end_write_request+0xcf/0x220 [raid1] [] bio_endio+0x5b/0xa0 [] blk_update_request+0x90/0x330 [] blk_update_bidi_request+0x1c/0x80 [] blk_end_bidi_request+0x1f/0x60 [] blk_end_request+0x10/0x20 [] scsi_io_completion+0xf4/0x6e0 [] scsi_finish_command+0xb3/0x110 [] scsi_softirq_done+0x137/0x160 [] blk_done_softirq+0x90/0xb0 [] __do_softirq+0x125/0x300 [] irq_exit+0xc5/0xd0 [] smp_call_function_single_interrupt+0x35/0x40 [] call_function_single_interrupt+0x72/0x80 [] ? native_safe_halt+0x6/0x10 [] ? trace_hardirqs_on+0xd/0x10 [] default_idle+0x24/0xe0 [] arch_cpu_idle+0xf/0x20 [] cpu_startup_entry+0x2cb/0x450 [] ? clockevents_register_device+0xbc/0x120 [] start_secondary+0x1de/0x290 = inconsistent lock state ] 3.16.0-rc1+ #35 Not tainted - inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/3/0 [HC0[0]:SC1[1]:HE0:SE0] takes: (kernfs_mutex){+.?.+.}, at: [] kernfs_notify+0x8a/0x140 {SOFTIRQ-ON-W} state was registered at: [] __lock_acquire+0x316/0x1a60 [] lock_acquire+0xa2/0x130 [] mutex_lock_nested+0x6a/0x3a0 [] kernfs_activate+0x1f/0xf0 [] kernfs_create_root+0xe8/0x110 [] sysfs_init+0x13/0x51 [] mnt_init+0x118/0x225 [] vfs_caches_init+0x99/0x115 [] start_kernel+0x3ec/0x443 [] x86_64_start_reservations+0x2a/0x2c [] x86_64_start_kernel+0x13e/0x14d 211959 hardirqs last enabled at (211958): [] _raw_spin_unlock_irqrestore+0x36/0x70 hardirqs last disabled at (211959): [] _raw_spin_lock_irqsave+0x29/0x70 softirqs last enabled at (211952): [] _local_bh_enable+0x22/0x50 softirqs last disabled at (211953): [] irq_exit+0xc5/0xd0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 lock(kernfs_mutex); lock(kernfs_mutex); *** DEADLOCK *** 1 lock held by swapper/3/0: #0: (&(>counts.lock)->rlock){..-...}, at: [] bitmap_endwrite+0x58/0x230 stack backtrace: swapper/3 Not tainted 3.16.0-rc1+ #35 Hewlett-Packard HP xw8400 Workstation/0A08h, BIOS 786D5 v02.38 10/25/2010 82638c50 88047fcc3a20 81706ef2 8804695edb40 88047fcc3a70 81702a16 0001 8804 8804 0006 8804695edb40 810d7c20 Call Trace: [] dump_stack+0x4d/0x66 [] print_usage_bug+0x1f3/0x204 [] ? check_usage_backwards+0x140/0x140 [] mark_lock+0x222/0x2b0 [] __lock_acquire+0x2b8/0x1a60 [] ? show_trace_log_lvl+0x4d/0x60 [] ? show_stack_log_lvl+0xa4/0x190 [] lock_acquire+0xa2/0x130 [] ? kernfs_notify+0x8a/0x140 [] mutex_lock_nested+0x6a/0x3a0 [] ? kernfs_notify+0x8a/0x140 [] kernfs_notify+0x8a/0x140 [] bitmap_endwrite+0xb9/0x230 [] close_write+0x93/0xb0 [raid1] [] r1_bio_write_done+0x29/0x50 [raid1] [] raid1_end_write_request+0xcf/0x220 [raid1] [] bio_endio+0x5b/0xa0 [] blk_update_request+0x90/0x330 [] blk_update_bidi_request+0x1c/0x80 [] blk_end_bidi_request+0x1f/0x60 [] blk_end_request+0x10/0x20 [] scsi_io_completion+0xf4/0x6e0 [] scsi_finish_command+0xb3/0x110 [] scsi_softirq_done+0x137/0x160 [] blk_done_softirq+0x90/0xb0 [] __do_softirq+0x125/0x300 [] irq_exit+0xc5/0xd0 [] smp_call_function_single_interrupt+0x35/0x40 [] call_function_single_interrupt+0x72/0x80 [] ? native_safe_halt+0x6/0x10 [] ? trace_hardirqs_on+0xd/0x10 [] default_idle+0x24/0xe0 [] arch_cpu_idle+0xf/0x20 [] cpu_startup_entry+0x2cb/0x450 [] ? clockevents_register_device+0xbc/0x120 [] start_secondary+0x1de/0x290 > Is this a known issue? Are there any patches I can help > test? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to
3.16-rc1 kernel BUG triggered at mutex.c:586
Trying to boot 3.16.0-rc1+ (the + is a small vlan related patch) on a tests system triggers the following BUG: Jun 16 13:54:50 scratch kernel: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:586 Jun 16 13:54:50 scratch kernel: in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/3 Jun 16 13:54:50 scratch kernel: 1 lock held by swapper/3/0: Jun 16 13:54:50 scratch kernel: #0: (&(>counts.lock)->rlock){..-...}, at: [] bitmap_endwrite+0x58/0x230 Jun 16 13:54:50 scratch kernel: irq event stamp: 211959 Jun 16 13:54:50 scratch kernel: hardirqs last enabled at (211958): [] _raw_spin_unlock_irqrestore+0x36/0x70 Jun 16 13:54:50 scratch kernel: hardirqs last disabled at (211959): [] _raw_spin_lock_irqsave+0x29/0x70 Jun 16 13:54:50 scratch kernel: softirqs last enabled at (211952): [] _local_bh_enable+0x22/0x50 Jun 16 13:54:50 scratch kernel: softirqs last disabled at (211953): [] irq_exit+0xc5/0xd0 Jun 16 13:54:50 scratch kernel: CPU: 3 PID: 0 Comm: swapper/3 Not tainted 3.16.0-rc1+ #35 Jun 16 13:54:50 scratch kernel: Hardware name: Hewlett-Packard HP xw8400 Workstation/0A08h, BIOS 786D5 v02.38 10/25/2010 Jun 16 13:54:50 scratch kernel: 88047fcc3bd0 81706ef2 81c857e0 Jun 16 13:54:50 scratch kernel: 88047fcc3be0 810b4dba 88047fcc3c50 8170c79c Jun 16 13:54:50 scratch kernel: 81c85938 0046 0092 Jun 16 13:54:50 scratch kernel: Call Trace: Jun 16 13:54:50 scratch kernel: [] dump_stack+0x4d/0x66 Jun 16 13:54:50 scratch kernel: [] __might_sleep+0xfa/0x130 Jun 16 13:54:50 scratch kernel: [] mutex_lock_nested+0x3c/0x3a0 Jun 16 13:54:50 scratch kernel: [] kernfs_notify+0x8a/0x140 Jun 16 13:54:50 scratch kernel: [] bitmap_endwrite+0xb9/0x230 Jun 16 13:54:50 scratch kernel: [] close_write+0x93/0xb0 [raid1] Jun 16 13:54:50 scratch kernel: [] r1_bio_write_done+0x29/0x50 [raid1] Jun 16 13:54:50 scratch kernel: [] raid1_end_write_request+0xcf/0x220 [raid1] Jun 16 13:54:50 scratch kernel: [] bio_endio+0x5b/0xa0 Jun 16 13:54:50 scratch kernel: [] blk_update_request+0x90/0x330 Jun 16 13:54:50 scratch kernel: [] blk_update_bidi_request+0x1c/0x80 Jun 16 13:54:50 scratch kernel: [] blk_end_bidi_request+0x1f/0x60 Jun 16 13:54:50 scratch kernel: [] blk_end_request+0x10/0x20 Jun 16 13:54:50 scratch kernel: [] scsi_io_completion+0xf4/0x6e0 Jun 16 13:54:50 scratch kernel: [] scsi_finish_command+0xb3/0x110 Jun 16 13:54:50 scratch kernel: [] scsi_softirq_done+0x137/0x160 Jun 16 13:54:50 scratch kernel: [] blk_done_softirq+0x90/0xb0 Jun 16 13:54:50 scratch kernel: [] __do_softirq+0x125/0x300 Jun 16 13:54:50 scratch kernel: [] irq_exit+0xc5/0xd0 Jun 16 13:54:50 scratch kernel: [] smp_call_function_single_interrupt+0x35/0x40 Jun 16 13:54:50 scratch kernel: [] call_function_single_interrupt+0x72/0x80 Jun 16 13:54:50 scratch kernel: [] ? native_safe_halt+0x6/0x10 Jun 16 13:54:50 scratch kernel: [] ? trace_hardirqs_on+0xd/0x10 Jun 16 13:54:50 scratch kernel: [] default_idle+0x24/0xe0 Jun 16 13:54:50 scratch kernel: [] arch_cpu_idle+0xf/0x20 Jun 16 13:54:50 scratch kernel: [] cpu_startup_entry+0x2cb/0x450 Jun 16 13:54:50 scratch kernel: [] ? clockevents_register_device+0xbc/0x120 Jun 16 13:54:50 scratch kernel: [] start_secondary+0x1de/0x290 Jun 16 13:54:50 scratch kernel: Jun 16 13:54:50 scratch kernel: = Jun 16 13:54:50 scratch kernel: [ INFO: inconsistent lock state ] Jun 16 13:54:50 scratch kernel: 3.16.0-rc1+ #35 Not tainted Jun 16 13:54:50 scratch kernel: - Jun 16 13:54:50 scratch kernel: inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. Jun 16 13:54:50 scratch kernel: swapper/3/0 [HC0[0]:SC1[1]:HE0:SE0] takes: Jun 16 13:54:50 scratch kernel: (kernfs_mutex){+.?.+.}, at: [] kernfs_notify+0x8a/0x140 Jun 16 13:54:50 scratch kernel: {SOFTIRQ-ON-W} state was registered at: Jun 16 13:54:50 scratch kernel: [] __lock_acquire+0x316/0x1a60 Jun 16 13:54:50 scratch kernel: [] lock_acquire+0xa2/0x130 Jun 16 13:54:50 scratch kernel: [] mutex_lock_nested+0x6a/0x3a0 Jun 16 13:54:50 scratch kernel: [] kernfs_activate+0x1f/0xf0 Jun 16 13:54:50 scratch kernel: [] kernfs_create_root+0xe8/0x110 Jun 16 13:54:50 scratch kernel: [] sysfs_init+0x13/0x51 Jun 16 13:54:50 scratch kernel: [] mnt_init+0x118/0x225 Jun 16 13:54:50 scratch kernel: [] vfs_caches_init+0x99/0x115 Jun 16 13:54:50 scratch kernel: [] start_kernel+0x3ec/0x443 Jun 16 13:54:50 scratch kernel: [] x86_64_start_reservations+0x2a/0x2c Jun 16 13:54:50 scratch kernel: [] x86_64_start_kernel+0x13e/0x14d Jun 16 13:54:50 scratch kernel: irq event stamp: 211959 Jun 16 13:54:50 scratch kernel: hardirqs last enabled at (211958): [] _raw_spin_unlock_irqrestore+0x36/0x70 Jun 16 13:54:50 scratch kernel: hardirqs last disabled at (211959): [] _raw_spin_lock_irqsave+0x29/0x70 Jun 16 13:54:50 scratch kernel: softirqs last enabled at (211952): [] _local_bh_enable+0x22/0x50 Jun 16 13:54:50
3.16-rc1 kernel BUG triggered at mutex.c:586
Trying to boot 3.16.0-rc1+ (the + is a small vlan related patch) on a tests system triggers the following BUG: Jun 16 13:54:50 scratch kernel: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:586 Jun 16 13:54:50 scratch kernel: in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/3 Jun 16 13:54:50 scratch kernel: 1 lock held by swapper/3/0: Jun 16 13:54:50 scratch kernel: #0: ((bitmap-counts.lock)-rlock){..-...}, at: [815729e8] bitmap_endwrite+0x58/0x230 Jun 16 13:54:50 scratch kernel: irq event stamp: 211959 Jun 16 13:54:50 scratch kernel: hardirqs last enabled at (211958): [8170f4d6] _raw_spin_unlock_irqrestore+0x36/0x70 Jun 16 13:54:50 scratch kernel: hardirqs last disabled at (211959): [8170fba9] _raw_spin_lock_irqsave+0x29/0x70 Jun 16 13:54:50 scratch kernel: softirqs last enabled at (211952): [8108bab2] _local_bh_enable+0x22/0x50 Jun 16 13:54:50 scratch kernel: softirqs last disabled at (211953): [8108cc15] irq_exit+0xc5/0xd0 Jun 16 13:54:50 scratch kernel: CPU: 3 PID: 0 Comm: swapper/3 Not tainted 3.16.0-rc1+ #35 Jun 16 13:54:50 scratch kernel: Hardware name: Hewlett-Packard HP xw8400 Workstation/0A08h, BIOS 786D5 v02.38 10/25/2010 Jun 16 13:54:50 scratch kernel: 88047fcc3bd0 81706ef2 81c857e0 Jun 16 13:54:50 scratch kernel: 88047fcc3be0 810b4dba 88047fcc3c50 8170c79c Jun 16 13:54:50 scratch kernel: 81c85938 0046 0092 Jun 16 13:54:50 scratch kernel: Call Trace: Jun 16 13:54:50 scratch kernel: IRQ [81706ef2] dump_stack+0x4d/0x66 Jun 16 13:54:50 scratch kernel: [810b4dba] __might_sleep+0xfa/0x130 Jun 16 13:54:50 scratch kernel: [8170c79c] mutex_lock_nested+0x3c/0x3a0 Jun 16 13:54:50 scratch kernel: [81270f5a] kernfs_notify+0x8a/0x140 Jun 16 13:54:50 scratch kernel: [81572a49] bitmap_endwrite+0xb9/0x230 Jun 16 13:54:50 scratch kernel: [a027a823] close_write+0x93/0xb0 [raid1] Jun 16 13:54:50 scratch kernel: [a027af89] r1_bio_write_done+0x29/0x50 [raid1] Jun 16 13:54:50 scratch kernel: [a027c98f] raid1_end_write_request+0xcf/0x220 [raid1] Jun 16 13:54:50 scratch kernel: [8132f0bb] bio_endio+0x5b/0xa0 Jun 16 13:54:50 scratch kernel: [81335f60] blk_update_request+0x90/0x330 Jun 16 13:54:50 scratch kernel: [8133621c] blk_update_bidi_request+0x1c/0x80 Jun 16 13:54:50 scratch kernel: [8133656f] blk_end_bidi_request+0x1f/0x60 Jun 16 13:54:50 scratch kernel: [813365c0] blk_end_request+0x10/0x20 Jun 16 13:54:50 scratch kernel: [81497194] scsi_io_completion+0xf4/0x6e0 Jun 16 13:54:50 scratch kernel: [8148c613] scsi_finish_command+0xb3/0x110 Jun 16 13:54:50 scratch kernel: [81496fb7] scsi_softirq_done+0x137/0x160 Jun 16 13:54:50 scratch kernel: [8133cfe0] blk_done_softirq+0x90/0xb0 Jun 16 13:54:50 scratch kernel: [8108c705] __do_softirq+0x125/0x300 Jun 16 13:54:50 scratch kernel: [8108cc15] irq_exit+0xc5/0xd0 Jun 16 13:54:50 scratch kernel: [810439d5] smp_call_function_single_interrupt+0x35/0x40 Jun 16 13:54:50 scratch kernel: [81711552] call_function_single_interrupt+0x72/0x80 Jun 16 13:54:50 scratch kernel: EOI [81053fa6] ? native_safe_halt+0x6/0x10 Jun 16 13:54:50 scratch kernel: [810d891d] ? trace_hardirqs_on+0xd/0x10 Jun 16 13:54:50 scratch kernel: [8101e0c4] default_idle+0x24/0xe0 Jun 16 13:54:50 scratch kernel: [8101ea6f] arch_cpu_idle+0xf/0x20 Jun 16 13:54:50 scratch kernel: [810d0d1b] cpu_startup_entry+0x2cb/0x450 Jun 16 13:54:50 scratch kernel: [810fed4c] ? clockevents_register_device+0xbc/0x120 Jun 16 13:54:50 scratch kernel: [810442ee] start_secondary+0x1de/0x290 Jun 16 13:54:50 scratch kernel: Jun 16 13:54:50 scratch kernel: = Jun 16 13:54:50 scratch kernel: [ INFO: inconsistent lock state ] Jun 16 13:54:50 scratch kernel: 3.16.0-rc1+ #35 Not tainted Jun 16 13:54:50 scratch kernel: - Jun 16 13:54:50 scratch kernel: inconsistent {SOFTIRQ-ON-W} - {IN-SOFTIRQ-W} usage. Jun 16 13:54:50 scratch kernel: swapper/3/0 [HC0[0]:SC1[1]:HE0:SE0] takes: Jun 16 13:54:50 scratch kernel: (kernfs_mutex){+.?.+.}, at: [81270f5a] kernfs_notify+0x8a/0x140 Jun 16 13:54:50 scratch kernel: {SOFTIRQ-ON-W} state was registered at: Jun 16 13:54:50 scratch kernel: [810d8f66] __lock_acquire+0x316/0x1a60 Jun 16 13:54:50 scratch kernel: [810dae72] lock_acquire+0xa2/0x130 Jun 16 13:54:50 scratch kernel: [8170c7ca] mutex_lock_nested+0x6a/0x3a0 Jun 16 13:54:50 scratch kernel: [8127066f] kernfs_activate+0x1f/0xf0 Jun 16 13:54:50 scratch kernel: [81270a08] kernfs_create_root+0xe8/0x110 Jun 16 13:54:50 scratch kernel: [81d73567] sysfs_init+0x13/0x51 Jun 16 13:54:50 scratch kernel: [81d70d06]
Re: 3.16-rc1 kernel BUG triggered at mutex.c:586
On Mon, 2014-06-16 at 14:28 -0400, Vlad Yasevich wrote: Trying to boot 3.16.0-rc1+ (the + is a small vlan related patch) on a tests system triggers the following BUG: It's easier for developers to read if you dump dmesg, or at least tell your mail client to please not make a line-wrapped mess of your report. replaces the gawd awful mess your mailer made BUG: sleeping function called from invalid context at kernel/locking/mutex.c:586 in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/3 1 lock held by swapper/3/0: #0: ((bitmap-counts.lock)-rlock){..-...}, at: [815729e8] bitmap_endwrite+0x58/0x230 211959 hardirqs last enabled at (211958): [8170f4d6] _raw_spin_unlock_irqrestore+0x36/0x70 hardirqs last disabled at (211959): [8170fba9] _raw_spin_lock_irqsave+0x29/0x70 softirqs last enabled at (211952): [8108bab2] _local_bh_enable+0x22/0x50 softirqs last disabled at (211953): [8108cc15] irq_exit+0xc5/0xd0 swapper/3 Not tainted 3.16.0-rc1+ #35 Hewlett-Packard HP xw8400 Workstation/0A08h, BIOS 786D5 v02.38 10/25/2010 88047fcc3bd0 81706ef2 81c857e0 88047fcc3be0 810b4dba 88047fcc3c50 8170c79c 81c85938 0046 0092 Call Trace: IRQ [81706ef2] dump_stack+0x4d/0x66 [810b4dba] __might_sleep+0xfa/0x130 [8170c79c] mutex_lock_nested+0x3c/0x3a0 [81270f5a] kernfs_notify+0x8a/0x140 [81572a49] bitmap_endwrite+0xb9/0x230 [a027a823] close_write+0x93/0xb0 [raid1] [a027af89] r1_bio_write_done+0x29/0x50 [raid1] [a027c98f] raid1_end_write_request+0xcf/0x220 [raid1] [8132f0bb] bio_endio+0x5b/0xa0 [81335f60] blk_update_request+0x90/0x330 [8133621c] blk_update_bidi_request+0x1c/0x80 [8133656f] blk_end_bidi_request+0x1f/0x60 [813365c0] blk_end_request+0x10/0x20 [81497194] scsi_io_completion+0xf4/0x6e0 [8148c613] scsi_finish_command+0xb3/0x110 [81496fb7] scsi_softirq_done+0x137/0x160 [8133cfe0] blk_done_softirq+0x90/0xb0 [8108c705] __do_softirq+0x125/0x300 [8108cc15] irq_exit+0xc5/0xd0 [810439d5] smp_call_function_single_interrupt+0x35/0x40 [81711552] call_function_single_interrupt+0x72/0x80 EOI [81053fa6] ? native_safe_halt+0x6/0x10 [810d891d] ? trace_hardirqs_on+0xd/0x10 [8101e0c4] default_idle+0x24/0xe0 [8101ea6f] arch_cpu_idle+0xf/0x20 [810d0d1b] cpu_startup_entry+0x2cb/0x450 [810fed4c] ? clockevents_register_device+0xbc/0x120 [810442ee] start_secondary+0x1de/0x290 = inconsistent lock state ] 3.16.0-rc1+ #35 Not tainted - inconsistent {SOFTIRQ-ON-W} - {IN-SOFTIRQ-W} usage. swapper/3/0 [HC0[0]:SC1[1]:HE0:SE0] takes: (kernfs_mutex){+.?.+.}, at: [81270f5a] kernfs_notify+0x8a/0x140 {SOFTIRQ-ON-W} state was registered at: [810d8f66] __lock_acquire+0x316/0x1a60 [810dae72] lock_acquire+0xa2/0x130 [8170c7ca] mutex_lock_nested+0x6a/0x3a0 [8127066f] kernfs_activate+0x1f/0xf0 [81270a08] kernfs_create_root+0xe8/0x110 [81d73567] sysfs_init+0x13/0x51 [81d70d06] mnt_init+0x118/0x225 [81d70923] vfs_caches_init+0x99/0x115 [81d43022] start_kernel+0x3ec/0x443 [81d425ee] x86_64_start_reservations+0x2a/0x2c [81d4272e] x86_64_start_kernel+0x13e/0x14d 211959 hardirqs last enabled at (211958): [8170f4d6] _raw_spin_unlock_irqrestore+0x36/0x70 hardirqs last disabled at (211959): [8170fba9] _raw_spin_lock_irqsave+0x29/0x70 softirqs last enabled at (211952): [8108bab2] _local_bh_enable+0x22/0x50 softirqs last disabled at (211953): [8108cc15] irq_exit+0xc5/0xd0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 lock(kernfs_mutex); Interrupt lock(kernfs_mutex); *** DEADLOCK *** 1 lock held by swapper/3/0: #0: ((bitmap-counts.lock)-rlock){..-...}, at: [815729e8] bitmap_endwrite+0x58/0x230 stack backtrace: swapper/3 Not tainted 3.16.0-rc1+ #35 Hewlett-Packard HP xw8400 Workstation/0A08h, BIOS 786D5 v02.38 10/25/2010 82638c50 88047fcc3a20 81706ef2 8804695edb40 88047fcc3a70 81702a16 0001 8804 8804 0006 8804695edb40 810d7c20 Call Trace: IRQ [81706ef2] dump_stack+0x4d/0x66 [81702a16] print_usage_bug+0x1f3/0x204 [810d7c20] ? check_usage_backwards+0x140/0x140 [810d8622] mark_lock+0x222/0x2b0 [810d8f08] __lock_acquire+0x2b8/0x1a60 [8101779d] ? show_trace_log_lvl+0x4d/0x60 [810163f4] ? show_stack_log_lvl+0xa4/0x190 [810dae72] lock_acquire+0xa2/0x130 [81270f5a] ? kernfs_notify+0x8a/0x140 [8170c7ca] mutex_lock_nested+0x6a/0x3a0