[  563.336820] ======================================================
[  563.355336] [ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ]
[  563.375411] 3.5.0-rc2+ #1 Not tainted
[  563.386367] ------------------------------------------------------
[  563.404881] gatord-child/2791 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
[  563.425780]  (bdev_lock){+.+...}, at: [<c00c11e7>] nr_blockdev_pages+0xb/0x40
[  563.447151] 
[  563.447151] and this task is already holding:
[  563.464652]  (&rq->lock){-.-.-.}, at: [<c038549f>] __schedule+0x93/0x640
[  563.484721] which would create a new lock dependency:
[  563.499870]  (&rq->lock){-.-.-.} -> (bdev_lock){+.+...}
[  563.515514] 
[  563.515514] but this new dependency connects a HARDIRQ-irq-safe lock:
[  563.539245]  (&rq->lock){-.-.-.}
[  563.539245] ... which became HARDIRQ-irq-safe at:
[  563.562998]   [<c004e07d>] __lock_acquire+0x739/0x139c
[  563.578395]   [<c004f057>] lock_acquire+0x5f/0xbc
[  563.592491]   [<c0386179>] _raw_spin_lock+0x21/0x2c
[  563.607124]   [<c0039383>] scheduler_tick+0x2f/0x11c
[  563.622014]   [<c00238db>] update_process_times+0x3f/0x48
[  563.638189]   [<c0049611>] tick_periodic+0x31/0x90
[  563.652541]   [<c00496dd>] tick_handle_periodic+0x1d/0x64
[  563.668718]   [<c00166f7>] sp804_timer_interrupt+0x1f/0x2c
[  563.685163]   [<c005ff9f>] handle_irq_event_percpu+0x3b/0x1a4
[  563.702379]   [<c0060131>] handle_irq_event+0x29/0x3c
[  563.717519]   [<c0061d29>] handle_fasteoi_irq+0x5d/0xcc
[  563.733174]   [<c005fabb>] generic_handle_irq+0x17/0x2c
[  563.748839]   [<c000d26d>] handle_IRQ+0x35/0x7c
[  563.762409]   [<c0008365>] gic_handle_irq+0x19/0x40
[  563.777021]   [<c000c4bf>] __irq_svc+0x3f/0x80
[  563.790340]   [<c037d114>] calibrate_delay+0x70/0x16c
[  563.805477]   [<c052a55b>] start_kernel+0x1df/0x270
[  563.820085]   [<6000804f>] 0x6000804f
[  563.831041] 
[  563.831041] to a HARDIRQ-irq-unsafe lock:
[  563.847483]  (bdev_lock){+.+...}
[  563.847483] ... which became HARDIRQ-irq-unsafe at:
[  563.871745] ...  [<c004dfc5>] __lock_acquire+0x681/0x139c
[  563.887921]   [<c004f057>] lock_acquire+0x5f/0xbc
[  563.902015]   [<c0386179>] _raw_spin_lock+0x21/0x2c
[  563.916631]   [<c00c11e7>] nr_blockdev_pages+0xb/0x40
[  563.931770]   [<c007db81>] si_meminfo+0x29/0x38
[  563.945354]   [<c053594d>] eventpoll_init+0x15/0x90
[  563.959965]   [<c0008445>] do_one_initcall+0x21/0x108
[  563.975096]   [<c052a6ab>] kernel_init+0xbf/0x14c
[  563.989193]   [<c000d455>] kernel_thread_exit+0x1/0x8
[  564.004314] 
[  564.004314] other info that might help us debug this:
[  564.004314] 
[  564.028296]  Possible interrupt unsafe locking scenario:
[  564.028296] 
[  564.048629]        CPU0                    CPU1
[  564.062187]        ----                    ----
[  564.075753]   lock(bdev_lock);
[  564.084884]                                local_irq_disable();
[  564.102617]                                lock(&rq->lock);
[  564.119307]                                lock(bdev_lock);
[  564.135990]   <Interrupt>
[  564.143825]     lock(&rq->lock);
[  564.153477] 
[  564.153477]  *** DEADLOCK ***
[  564.153477] 
[  564.171213] 1 lock held by gatord-child/2791:
[  564.184281]  #0:  (&rq->lock){-.-.-.}, at: [<c038549f>] __schedule+0x93/0x640
[  564.205658] 
[  564.205658] the dependencies between HARDIRQ-irq-safe lock and the holding lock:
[  564.232311] -> (&rq->lock){-.-.-.} ops: 908579 {
[  564.246137]    IN-HARDIRQ-W at:
[  564.255548]  [<c004e07d>] __lock_acquire+0x739/0x139c
[  564.270682]  [<c004f057>] lock_acquire+0x5f/0xbc
[  564.284515]  [<c0386179>] _raw_spin_lock+0x21/0x2c
[  564.298876]  [<c0039383>] scheduler_tick+0x2f/0x11c
[  564.313496]  [<c00238db>] update_process_times+0x3f/0x48
[  564.329410]  [<c0049611>] tick_periodic+0x31/0x90
[  564.343501]  [<c00496dd>] tick_handle_periodic+0x1d/0x64
[  564.359416]  [<c00166f7>] sp804_timer_interrupt+0x1f/0x2c
[  564.375594]  [<c005ff9f>] handle_irq_event_percpu+0x3b/0x1a4
[  564.392550]  [<c0060131>] handle_irq_event+0x29/0x3c
[  564.407425]  [<c0061d29>] handle_fasteoi_irq+0x5d/0xcc
[  564.422817]  [<c005fabb>] generic_handle_irq+0x17/0x2c
[  564.438215]  [<c000d26d>] handle_IRQ+0x35/0x7c
[  564.451523]  [<c0008365>] gic_handle_irq+0x19/0x40
[  564.465873]  [<c000c4bf>] __irq_svc+0x3f/0x80
[  564.478926]  [<c037d114>] calibrate_delay+0x70/0x16c
[  564.493799]  [<c052a55b>] start_kernel+0x1df/0x270
[  564.508148]  [<6000804f>] 0x6000804f
[  564.518847]    IN-SOFTIRQ-W at:
[  564.528256]  [<c004dfaf>] __lock_acquire+0x66b/0x139c
[  564.543390]  [<c004f057>] lock_acquire+0x5f/0xbc
[  564.557225]  [<c0386179>] _raw_spin_lock+0x21/0x2c
[  564.571585]  [<c003a1db>] try_to_wake_up+0x14b/0x238
[  564.586468]  [<c002abe9>] __queue_work+0xad/0x308
[  564.600566]  [<c0022f27>] run_timer_softirq+0xf7/0x29c
[  564.615958]  [<c001e345>] __do_softirq+0xb5/0x1a0
[  564.630047]  [<c001e73f>] irq_exit+0x5f/0x64
[  564.642839]  [<c000d271>] handle_IRQ+0x39/0x7c
[  564.656147]  [<c0008365>] gic_handle_irq+0x19/0x40
[  564.670498]  [<c000c4bf>] __irq_svc+0x3f/0x80
[  564.683551]  [<c03865b0>] _raw_spin_unlock_irqrestore+0x24/0x34
[  564.701292]  [<c00178b5>] mm_release+0x51/0x9c
[  564.714609]  [<c001b491>] exit_mm+0x11/0xf0
[  564.727141]  [<c001c68f>] do_exit+0xe7/0x59c
[  564.739932]  [<c000d459>] kernel_thread_exit+0x5/0x8
[  564.754798]    IN-RECLAIM_FS-W at:
[  564.764989]  [<c004e065>] __lock_acquire+0x721/0x139c
[  564.780123]  [<c004f057>] lock_acquire+0x5f/0xbc
[  564.793954]  [<c0386179>] _raw_spin_lock+0x21/0x2c
[  564.808309]  [<c00355e7>] task_rq_lock+0x2f/0x5c
[  564.822147]  [<c003a449>] set_cpus_allowed_ptr+0x15/0xe0
[  564.838061]  [<c0086957>] kswapd+0x5ab/0x674
[  564.850852]  [<c002edc7>] kthread+0x5b/0x68
[  564.863383]  [<c000d455>] kernel_thread_exit+0x1/0x8
[  564.878249]    INITIAL USE at:
[  564.887393]  [<c004db51>] __lock_acquire+0x20d/0x139c
[  564.902528]  [<c004f057>] lock_acquire+0x5f/0xbc
[  564.916361]  [<c0386207>] _raw_spin_lock_irqsave+0x2b/0x38
[  564.932798]  [<c0036f8f>] rq_attach_root+0xf/0xf4
[  564.946889]  [<c053113f>] sched_init+0x11f/0x214
[  564.960719]  [<c052a4a3>] start_kernel+0x127/0x270
[  564.975066]  [<6000804f>] 0x6000804f
[  564.985759]  }
[  564.990744]  ... key      at: [<c05b4894>] __key.38721+0x0/0x2c
[  565.008470]  ... acquired at:
[  565.017354]    [<c004d3a1>] check_irq_usage+0x49/0x8c
[  565.032488]    [<c004e345>] __lock_acquire+0xa01/0x139c
[  565.048144]    [<c004f057>] lock_acquire+0x5f/0xbc
[  565.062495]    [<c0386179>] _raw_spin_lock+0x21/0x2c
[  565.077374]    [<c00c11e7>] nr_blockdev_pages+0xb/0x40
[  565.092773]    [<c007db81>] si_meminfo+0x29/0x38
[  565.106702]    [<bf803ea3>] wq_sched_handler+0x22/0xb8 [gator]
[  565.124214]    [<bf8040f5>] gator_events_meminfo_read+0x54/0x60 [gator]
[  565.144061]    [<bf801add>] collect_counters+0x54/0x110 [gator]
[  565.161819]    [<bf8025ff>] probe_sched_write+0x62/0x70 [gator]
[  565.179576]    [<bf802627>] probe_sched_switch+0xe/0x10 [gator]
[  565.197315]    [<c03859a9>] __schedule+0x59d/0x640
[  565.211687]    [<bf801449>] userspace_buffer_read+0x74/0x20c [gator]
[  565.230735]    [<c009ef01>] vfs_read+0x61/0xc4
[  565.244045]    [<c009ef8d>] sys_read+0x29/0x4c
[  565.257362]    [<c000c981>] ret_fast_syscall+0x1/0x52
[  565.272483] 
[  565.276934] 
[  565.276934] the dependencies between the lock to be acquired and HARDIRQ-irq-unsafe lock:
[  565.305932] -> (bdev_lock){+.+...} ops: 173 {
[  565.318976]    HARDIRQ-ON-W at:
[  565.328387]  [<c004dfc5>] __lock_acquire+0x681/0x139c
[  565.343522]  [<c004f057>] lock_acquire+0x5f/0xbc
[  565.357354]  [<c0386179>] _raw_spin_lock+0x21/0x2c
[  565.371711]  [<c00c11e7>] nr_blockdev_pages+0xb/0x40
[  565.386584]  [<c007db81>] si_meminfo+0x29/0x38
[  565.399906]  [<c053594d>] eventpoll_init+0x15/0x90
[  565.414257]  [<c0008445>] do_one_initcall+0x21/0x108
[  565.429129]  [<c052a6ab>] kernel_init+0xbf/0x14c
[  565.442963]  [<c000d455>] kernel_thread_exit+0x1/0x8
[  565.457829]    SOFTIRQ-ON-W at:
[  565.467238]  [<c004dfe3>] __lock_acquire+0x69f/0x139c
[  565.482371]  [<c004f057>] lock_acquire+0x5f/0xbc
[  565.496202]  [<c0386179>] _raw_spin_lock+0x21/0x2c
[  565.510555]  [<c00c11e7>] nr_blockdev_pages+0xb/0x40
[  565.525428]  [<c007db81>] si_meminfo+0x29/0x38
[  565.538740]  [<c053594d>] eventpoll_init+0x15/0x90
[  565.553092]  [<c0008445>] do_one_initcall+0x21/0x108
[  565.567961]  [<c052a6ab>] kernel_init+0xbf/0x14c
[  565.581794]  [<c000d455>] kernel_thread_exit+0x1/0x8
[  565.596660]    INITIAL USE at:
[  565.605806]  [<c004db51>] __lock_acquire+0x20d/0x139c
[  565.620940]  [<c004f057>] lock_acquire+0x5f/0xbc
[  565.634772]  [<c0386179>] _raw_spin_lock+0x21/0x2c
[  565.649124]  [<c00c11e7>] nr_blockdev_pages+0xb/0x40
[  565.663995]  [<c007db81>] si_meminfo+0x29/0x38
[  565.677305]  [<c053594d>] eventpoll_init+0x15/0x90
[  565.691655]  [<c0008445>] do_one_initcall+0x21/0x108
[  565.706527]  [<c052a6ab>] kernel_init+0xbf/0x14c
[  565.720360]  [<c000d455>] kernel_thread_exit+0x1/0x8
[  565.735221]  }
[  565.740210]  ... key      at: [<c055e3d0>] bdev_lock+0x10/0x40
[  565.757676]  ... acquired at:
[  565.766563]    [<c004d3a1>] check_irq_usage+0x49/0x8c
[  565.781697]    [<c004e345>] __lock_acquire+0xa01/0x139c
[  565.797353]    [<c004f057>] lock_acquire+0x5f/0xbc
[  565.811705]    [<c0386179>] _raw_spin_lock+0x21/0x2c
[  565.826580]    [<c00c11e7>] nr_blockdev_pages+0xb/0x40
[  565.841973]    [<c007db81>] si_meminfo+0x29/0x38
[  565.855853]    [<bf803ea3>] wq_sched_handler+0x22/0xb8 [gator]
[  565.873360]    [<bf8040f5>] gator_events_meminfo_read+0x54/0x60 [gator]
[  565.893204]    [<bf801add>] collect_counters+0x54/0x110 [gator]
[  565.910962]    [<bf8025ff>] probe_sched_write+0x62/0x70 [gator]
[  565.928719]    [<bf802627>] probe_sched_switch+0xe/0x10 [gator]
[  565.946458]    [<c03859a9>] __schedule+0x59d/0x640
[  565.960829]    [<bf801449>] userspace_buffer_read+0x74/0x20c [gator]
[  565.979869]    [<c009ef01>] vfs_read+0x61/0xc4
[  565.993179]    [<c009ef8d>] sys_read+0x29/0x4c
[  566.006492]    [<c000c981>] ret_fast_syscall+0x1/0x52
[  566.021612] 
[  566.026056] 
[  566.026056] stack backtrace:
[  566.039132] [<c0010f21>] (unwind_backtrace+0x1/0x98) from [<c004d20b>] (check_usage+0x2bb/0x408)
[  566.065474] [<c004d20b>] (check_usage+0x2bb/0x408) from [<c004d3a1>] (check_irq_usage+0x49/0x8c)
[  566.091815] [<c004d3a1>] (check_irq_usage+0x49/0x8c) from [<c004e345>] (__lock_acquire+0xa01/0x139c)
[  566.119196] [<c004e345>] (__lock_acquire+0xa01/0x139c) from [<c004f057>] (lock_acquire+0x5f/0xbc)
[  566.145796] [<c004f057>] (lock_acquire+0x5f/0xbc) from [<c0386179>] (_raw_spin_lock+0x21/0x2c)
[  566.171619] [<c0386179>] (_raw_spin_lock+0x21/0x2c) from [<c00c11e7>] (nr_blockdev_pages+0xb/0x40)
[  566.198480] [<c00c11e7>] (nr_blockdev_pages+0xb/0x40) from [<c007db81>] (si_meminfo+0x29/0x38)
[  566.224332] [<c007db81>] (si_meminfo+0x29/0x38) from [<bf803ea3>] (wq_sched_handler+0x22/0xb8 [gator])
[  566.252291] [<bf803ea3>] (wq_sched_handler+0x22/0xb8 [gator]) from [<bf8040f5>] (gator_events_meminfo_read+0x54/0x60 [gator])
[  566.286231] [<bf8040f5>] (gator_events_meminfo_read+0x54/0x60 [gator]) from [<bf801add>] (collect_counters+0x54/0x110 [gator])
[  566.320424] [<bf801add>] (collect_counters+0x54/0x110 [gator]) from [<bf8025ff>] (probe_sched_write+0x62/0x70 [gator])
[  566.352528] [<bf8025ff>] (probe_sched_write+0x62/0x70 [gator]) from [<bf802627>] (probe_sched_switch+0xe/0x10 [gator])
[  566.384614] [<bf802627>] (probe_sched_switch+0xe/0x10 [gator]) from [<c03859a9>] (__schedule+0x59d/0x640)
[  566.413316] [<c03859a9>] (__schedule+0x59d/0x640) from [<bf801449>] (userspace_buffer_read+0x74/0x20c [gator])
[  566.443321] [<bf801449>] (userspace_buffer_read+0x74/0x20c [gator]) from [<c009ef01>] (vfs_read+0x61/0xc4)
[  566.472263] [<c009ef01>] (vfs_read+0x61/0xc4) from [<c009ef8d>] (sys_read+0x29/0x4c)
[  566.495479] [<c009ef8d>] (sys_read+0x29/0x4c) from [<c000c981>] (ret_fast_syscall+0x1/0x52)