I'm using Ubuntu 14.04.1 LTS with the 4.4.0-104-generic kernel, and running a user-mode-linux heavy workload. Every now and then, the system locks up and is subsequently reset by the hardware watchdog. I have verified that the lockups go away if UML is not enabled. I have tried a variety of UML guest kernels, including 3.13.0-1um-0ubuntu1 (from Ubuntu repos), 3.16-1um-0.1+b2 (Debian) and 4.9-1um-1+b3 (Debian) and am seeing lockups across all of these. The lockups go away, however, when a 3.13 host kernel is used.

I am able to generate a crash and collect crash dumps during lockups by sending an NMI (kernel.unknown_nmi_panic = 1)


Below are dmesg logs collected on crash during one such lockup. I can attach the crash dump as well if this will be helpful.

[14532.482373] CPU: 9 PID: 23890 Comm: linux Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.482375] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.482377] task: ffff880efc143800 ti: ffff880168ef8000 task.ti: ffff880168ef8000
[14532.482379] RIP: 0010:[<ffffffff810c69d7>]  [<ffffffff810c69d7>] native_queued_spin_lock_slowpath+0x117/0x170
[14532.482385] RSP: 0018:ffff880168efbeb0  EFLAGS: 00000202
[14532.482387] RAX: 0000000000000000 RBX: ffffffff81e0b080 RCX: ffff880f46e57900
[14532.482388] RDX: 0000000000040101 RSI: 0000000000280000 RDI: ffffffff81e0b084
[14532.482390] RBP: ffff880168efbeb0 R08: 0000000000000101 R09: 0000000000000001
[14532.482391] R10: 0000000060afa4e0 R11: 0000000000000206 R12: ffffffff81e0b084
[14532.482393] R13: ffff8801e63d6200 R14: 0000000000000000 R15: 0000000060afa4e0
[14532.482395] FS:  00007f8c0e8cf740(0000) GS:ffff880f46e40000(0000) knlGS:0000000000000000
[14532.482396] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.482398] CR2: 0000000040741a80 CR3: 0000000197e57000 CR4: 00000000001406e0
[14532.482400] Stack:
[14532.482401]  ffff880168efbec0 ffffffff81184364 ffff880168efbee0 ffffffff810c7f96
[14532.482404]  ffff8801e63d6200 0000000000000000 ffff880168efbef0 ffffffff8180f293
[14532.482406]  ffff880168efbf10 ffffffff8108842e 000000000000000d 000000009fb24ac0
[14532.482409] Call Trace:
[14532.482414]  [<ffffffff81184364>] queued_spin_lock_slowpath+0xb/0xf
[14532.482416]  [<ffffffff810c7f96>] queued_read_lock_slowpath+0x76/0x80
[14532.482420]  [<ffffffff8180f293>] _raw_read_lock+0x23/0x30
[14532.482424]  [<ffffffff8108842e>] ptrace_check_attach+0x1e/0x140
[14532.482426]  [<ffffffff8108914e>] SyS_ptrace+0x8e/0x110
[14532.482429]  [<ffffffff8180f576>] entry_SYSCALL_64_fastpath+0x16/0x75
[14532.482431] Code: 30 48 98 48 81 c2 00 79 01 00 48 03 14 c5 c0 a0 f3 81 48 89 0a 8b 41 08 85 c0 75 0d f3 90 8b 41 08 85 c0 74 f7 eb 02 f3 90 8b 17 <66> 85 d2 75 f7 39 f2 66 90 75 0f 89 d0 be 01 00 00 00 f0 0f b1 
[14532.482459] Sending NMI to other CPUs:
[14532.484745] NMI backtrace for cpu 0
[14532.484747] CPU: 0 PID: 11657 Comm: cockroach Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.484748] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.484749] task: ffff880efc175400 ti: ffff880dbfbf4000 task.ti: ffff880dbfbf4000
[14532.484751] RIP: 0010:[<ffffffff810c69ca>]  [<ffffffff810c69ca>] native_queued_spin_lock_slowpath+0x10a/0x170
[14532.484752] RSP: 0018:ffff880dbfbf7d58  EFLAGS: 00000046
[14532.484753] RAX: 0000000000000000 RBX: ffffffff81e0b080 RCX: ffff880f46c17900
[14532.484754] RDX: ffff880f46d17900 RSI: 0000000000040000 RDI: ffffffff81e0b084
[14532.484756] RBP: ffff880dbfbf7d58 R08: 0000000000000101 R09: 0000000000000000
[14532.484757] R10: 0000000000000000 R11: 0000000000000246 R12: ffffffff81e0b084
[14532.484758] R13: 0000000000000007 R14: 0000000000020002 R15: ffff880ec8f27f80
[14532.484759] FS:  00007fb8aefff700(0000) GS:ffff880f46c00000(0000) knlGS:0000000000000000
[14532.484761] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.484762] CR2: 00007f9e82520a08 CR3: 0000000de63d2000 CR4: 00000000001406f0
[14532.484763] Stack:
[14532.484764]  ffff880dbfbf7d68 ffffffff81184364 ffff880dbfbf7d88 ffffffff810c7f96
[14532.484765]  ffff880ef9c22278 0000000000000246 ffff880dbfbf7d98 ffffffff8180f293
[14532.484767]  ffff880dbfbf7de0 ffffffff81214c82 0000000000000000 0000000181ec7c40
[14532.484768] Call Trace:
[14532.484769]  [<ffffffff81184364>] queued_spin_lock_slowpath+0xb/0xf
[14532.484770]  [<ffffffff810c7f96>] queued_read_lock_slowpath+0x76/0x80
[14532.484771]  [<ffffffff8180f293>] _raw_read_lock+0x23/0x30
[14532.484772]  [<ffffffff81214c82>] send_sigio+0x52/0x110
[14532.484774]  [<ffffffff81214da0>] kill_fasync+0x60/0x90
[14532.484775]  [<ffffffff81505baa>] account+0x13a/0x190
[14532.484776]  [<ffffffff81508d18>] ? urandom_read+0x48/0x110
[14532.484777]  [<ffffffff815089aa>] extract_entropy_user+0x6a/0x1a0
[14532.484778]  [<ffffffff81508d18>] urandom_read+0x48/0x110
[14532.484780]  [<ffffffff81508e68>] SyS_getrandom+0x48/0x120
[14532.484781]  [<ffffffff8180f576>] entry_SYSCALL_64_fastpath+0x16/0x75
[14532.484782] Code: c2 c1 e8 12 48 c1 ea 0c 83 e8 01 83 e2 30 48 98 48 81 c2 00 79 01 00 48 03 14 c5 c0 a0 f3 81 48 89 0a 8b 41 08 85 c0 75 0d f3 90 <8b> 41 08 85 c0 74 f7 eb 02 f3 90 8b 17 66 85 d2 75 f7 39 f2 66 
[14532.484784] NMI backtrace for cpu 1
[14532.484785] CPU: 1 PID: 2516 Comm: sdfs_main Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.484786] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.484787] task: ffff88066a42e200 ti: ffff88010c4e0000 task.ti: ffff88010c4e0000
[14532.484789] RIP: 0010:[<ffffffff810c69cd>]  [<ffffffff810c69cd>] native_queued_spin_lock_slowpath+0x10d/0x170
[14532.484790] RSP: 0000:ffff880f46c43de0  EFLAGS: 00000046
[14532.484791] RAX: 0000000000000000 RBX: 0000000000000046 RCX: ffff880f46c57900
[14532.484792] RDX: ffff880f46ed7910 RSI: 0000000000080000 RDI: ffff88016bc69c30
[14532.484794] RBP: ffff880f46c43de0 R08: 0000000000000101 R09: 0000000000000000
[14532.484795] R10: 000000000000001c R11: 0000000000007ffe R12: 0000000000000046
[14532.484796] R13: 000000000000001d R14: 0000000000020001 R15: ffffffff81d261ad
[14532.484797] FS:  00007fc6667fc700(0000) GS:ffff880f46c40000(0000) knlGS:0000000000000000
[14532.484799] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.484800] CR2: 00007ff6053a7000 CR3: 0000000ee6545000 CR4: 00000000001406e0
[14532.484801] Stack:
[14532.484802]  ffff880f46c43df0 ffffffff81184217 ffff880f46c43e08 ffffffff8180f357
[14532.484803]  ffff88016bc69c30 ffff880f46c43e38 ffffffff81214d75 0000000000000405
[14532.484805]  ffffffff81ec7ba0 0000000000000015 ffffffff81ec7bf0 ffff880f46c43e88
[14532.484806] Call Trace:
[14532.484807]  <IRQ> .d [<ffffffff81184217>] queued_spin_lock_slowpath+0xb/0xf
[14532.484808]  [<ffffffff8180f357>] _raw_spin_lock_irqsave+0x37/0x40
[14532.484809]  [<ffffffff81214d75>] kill_fasync+0x35/0x90
[14532.484811]  [<ffffffff81506020>] credit_entropy_bits+0x250/0x380
[14532.484812]  [<ffffffff8150649d>] ? add_interrupt_randomness+0x16d/0x1c0
[14532.484813]  [<ffffffff8150649d>] add_interrupt_randomness+0x16d/0x1c0
[14532.484814]  [<ffffffff810d6587>] handle_irq_event_percpu+0xa7/0x1d0
[14532.484815]  [<ffffffff810d66ee>] handle_irq_event+0x3e/0x60
[14532.484817]  [<ffffffff810d9b0c>] handle_edge_irq+0x9c/0x150
[14532.484818]  [<ffffffff810300c0>] handle_irq+0x20/0x30
[14532.484819]  [<ffffffff81811f5d>] do_IRQ+0x4d/0xd0
[14532.484820]  [<ffffffff81810042>] common_interrupt+0x82/0x82
[14532.484822]  <EOI> .dCode: 12 48 c1 ea 0c 83 e8 01 83 e2 30 48 98 48 81 c2 00 79 01 00 48 03 14 c5 c0 a0 f3 81 48 89 0a 8b 41 08 85 c0 75 0d f3 90 8b 41 08 <85> c0 74 f7 eb 02 f3 90 8b 17 66 85 d2 75 f7 39 f2 66 90 75 0f 
[14532.484823] NMI backtrace for cpu 2
[14532.484824] CPU: 2 PID: 25667 Comm: linux Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.484826] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.484827] task: ffff88010c6cf000 ti: ffff8801094d8000 task.ti: ffff8801094d8000
[14532.484828] RIP: 0010:[<ffffffff810c6a20>]  [<ffffffff810c6a20>] native_queued_spin_lock_slowpath+0x160/0x170
[14532.484829] RSP: 0000:ffff880f46c83de0  EFLAGS: 00000002
[14532.484831] RAX: 0000000000200101 RBX: 0000000000000046 RCX: 0000000000000001
[14532.484832] RDX: 0000000000000101 RSI: 0000000000000001 RDI: ffff88016bc69c30
[14532.484833] RBP: ffff880f46c83de0 R08: 0000000000000101 R09: 0000000000000000
[14532.484834] R10: 000000000000001c R11: 0000000000007ffe R12: 0000000000000046
[14532.484836] R13: 000000000000001d R14: 0000000000020001 R15: ffffffff81d261ad
[14532.484837] FS:  00007f6516e5f740(0000) GS:ffff880f46c80000(0000) knlGS:0000000000000000
[14532.484838] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.484839] CR2: 0000000000b03ea0 CR3: 00000001e600a000 CR4: 00000000001406e0
[14532.484840] Stack:
[14532.484842]  ffff880f46c83df0 ffffffff81184217 ffff880f46c83e08 ffffffff8180f357
[14532.484843]  ffff88016bc69c30 ffff880f46c83e38 ffffffff81214d75 0000000000000402
[14532.484844]  ffffffff81ec7ba0 000000000000000f ffffffff81ec7bf0 ffff880f46c83e88
[14532.484845] Call Trace:
[14532.484846]  <IRQ> .d [<ffffffff81184217>] queued_spin_lock_slowpath+0xb/0xf
[14532.484848]  [<ffffffff8180f357>] _raw_spin_lock_irqsave+0x37/0x40
[14532.484849]  [<ffffffff81214d75>] kill_fasync+0x35/0x90
[14532.484850]  [<ffffffff81506020>] credit_entropy_bits+0x250/0x380
[14532.484851]  [<ffffffff8150649d>] ? add_interrupt_randomness+0x16d/0x1c0
[14532.484852]  [<ffffffff8150649d>] add_interrupt_randomness+0x16d/0x1c0
[14532.484854]  [<ffffffff810d6587>] handle_irq_event_percpu+0xa7/0x1d0
[14532.484855]  [<ffffffff810d66ee>] handle_irq_event+0x3e/0x60
[14532.484856]  [<ffffffff810d9b0c>] handle_edge_irq+0x9c/0x150
[14532.484857]  [<ffffffff810300c0>] handle_irq+0x20/0x30
[14532.484858]  [<ffffffff81811f5d>] do_IRQ+0x4d/0xd0
[14532.484860]  [<ffffffff81810042>] common_interrupt+0x82/0x82
[14532.484861]  <EOI> .d [<ffffffff8108a4a3>] ? __sigqueue_free.part.14+0x33/0x40
[14532.484862]  [<ffffffff8109a958>] ? __task_pid_nr_ns+0x48/0xa0
[14532.484863]  [<ffffffff8108bcf5>] do_notify_parent_cldstop+0x55/0x190
[14532.484865]  [<ffffffff811e1601>] ? kmem_cache_free+0x1d1/0x1f0
[14532.484866]  [<ffffffff811ba9e4>] ? vma_adjust+0x4b4/0x6b0
[14532.484867]  [<ffffffff81184364>] ? queued_spin_lock_slowpath+0xb/0xf
[14532.484868]  [<ffffffff8108bf39>] ptrace_stop+0x109/0x270
[14532.484869]  [<ffffffff8108d7d4>] get_signal+0x3e4/0x610
[14532.484870]  [<ffffffff8108b29a>] ? signal_wake_up_state+0x2a/0x30
[14532.484872]  [<ffffffff8102d4a8>] do_signal+0x28/0x6c0
[14532.484873]  [<ffffffff8108b936>] ? __send_signal+0x176/0x460
[14532.484874]  [<ffffffff8118a2d0>] ? __probe_kernel_read+0x40/0x90
[14532.484875]  [<ffffffff8108c469>] ? force_sig_info+0xc9/0xe0
[14532.484876]  [<ffffffff8107989c>] exit_to_usermode_loop+0x59/0xa2
[14532.484878]  [<ffffffff81003a16>] prepare_exit_to_usermode+0x26/0x30
[14532.484879]  [<ffffffff81810065>] retint_user+0x8/0x13
[14532.484880] Code: 8b 01 48 85 c0 75 0a f3 90 48 8b 01 48 85 c0 74 f6 c7 40 08 01 00 00 00 e9 61 ff ff ff 83 fa 01 75 07 e9 c2 fe ff ff f3 90 8b 07 <84> c0 75 f8 b8 01 00 00 00 66 89 07 5d c3 66 90 0f 1f 44 00 00 
[14532.484882] NMI backtrace for cpu 3
[14532.484883] CPU: 3 PID: 29299 Comm: java Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.484884] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.484885] task: ffff880eed35d400 ti: ffff880a74604000 task.ti: ffff880a74604000
[14532.484887] RIP: 0010:[<ffffffff810c69d7>]  [<ffffffff810c69d7>] native_queued_spin_lock_slowpath+0x117/0x170
[14532.484888] RSP: 0018:ffff880f46cc3de0  EFLAGS: 00000002
[14532.484889] RAX: 0000000000000000 RBX: 0000000000000046 RCX: ffff880f46cd7900
[14532.484891] RDX: 0000000000200101 RSI: 0000000000100000 RDI: ffff88016bc69c30
[14532.484892] RBP: ffff880f46cc3de0 R08: 0000000000000101 R09: 0000000000000000
[14532.484893] R10: 000000000000001c R11: 0000000000007ffe R12: 0000000000000046
[14532.484894] R13: 000000000000001d R14: 0000000000020001 R15: ffffffff81d261ad
[14532.484895] FS:  00007f0b354a9700(0000) GS:ffff880f46cc0000(0000) knlGS:0000000000000000
[14532.484897] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.484898] CR2: 00007f388d2f8024 CR3: 0000000bdeed2000 CR4: 00000000001406e0
[14532.484899] Stack:
[14532.484900]  ffff880f46cc3df0 ffffffff81184217 ffff880f46cc3e08 ffffffff8180f357
[14532.484901]  ffff88016bc69c30 ffff880f46cc3e38 ffffffff81214d75 0000000000000402
[14532.484903]  ffffffff81ec7ba0 0000000000000010 ffffffff81ec7bf0 ffff880f46cc3e88
[14532.484904] Call Trace:
[14532.484905]  <IRQ> .d [<ffffffff81184217>] queued_spin_lock_slowpath+0xb/0xf
[14532.484906]  [<ffffffff8180f357>] _raw_spin_lock_irqsave+0x37/0x40
[14532.484907]  [<ffffffff81214d75>] kill_fasync+0x35/0x90
[14532.484908]  [<ffffffff81506020>] credit_entropy_bits+0x250/0x380
[14532.484910]  [<ffffffff8150649d>] ? add_interrupt_randomness+0x16d/0x1c0
[14532.484911]  [<ffffffff8150649d>] add_interrupt_randomness+0x16d/0x1c0
[14532.484912]  [<ffffffff810d6587>] handle_irq_event_percpu+0xa7/0x1d0
[14532.484913]  [<ffffffff810d66ee>] handle_irq_event+0x3e/0x60
[14532.484914]  [<ffffffff810d9b0c>] handle_edge_irq+0x9c/0x150
[14532.484916]  [<ffffffff810300c0>] handle_irq+0x20/0x30
[14532.484917]  [<ffffffff81811f5d>] do_IRQ+0x4d/0xd0
[14532.484918]  [<ffffffff81810042>] common_interrupt+0x82/0x82
[14532.484919]  <EOI> .d [<ffffffff816f0e1a>] ? sock_def_readable+0xa/0x60
[14532.484920]  [<ffffffff816f5b66>] ? kfree_skb_partial+0x36/0x40
[14532.484922]  [<ffffffff8175fb0b>] tcp_rcv_established+0x3cb/0x710
[14532.484923]  [<ffffffff8176a1ec>] tcp_v4_do_rcv+0x10c/0x210
[14532.484924]  [<ffffffff81753347>] tcp_prequeue_process+0x77/0xc0
[14532.484925]  [<ffffffff81754adc>] tcp_recvmsg+0x8bc/0xbc0
[14532.484926]  [<ffffffff81386c98>] ? aa_sk_perm+0x78/0x230
[14532.484928]  [<ffffffff817812df>] inet_recvmsg+0x6f/0x80
[14532.484929]  [<ffffffff816ed61d>] sock_recvmsg+0x3d/0x50
[14532.484930]  [<ffffffff816ed838>] SYSC_recvfrom+0xd8/0x150
[14532.484931]  [<ffffffff811222cf>] ? __audit_syscall_entry+0xaf/0x100
[14532.484932]  [<ffffffff81003176>] ? do_audit_syscall_entry+0x66/0x70
[14532.484933]  [<ffffffff810037d9>] ? syscall_trace_enter_phase1+0xf9/0x110
[14532.484935]  [<ffffffff810797c5>] ? syscall_slow_exit_work+0x3f/0xbd
[14532.484936]  [<ffffffff816eeafe>] SyS_recvfrom+0xe/0x10
[14532.484937]  [<ffffffff8180f576>] entry_SYSCALL_64_fastpath+0x16/0x75
[14532.484939] Code: 30 48 98 48 81 c2 00 79 01 00 48 03 14 c5 c0 a0 f3 81 48 89 0a 8b 41 08 85 c0 75 0d f3 90 8b 41 08 85 c0 74 f7 eb 02 f3 90 8b 17 <66> 85 d2 75 f7 39 f2 66 90 75 0f 89 d0 be 01 00 00 00 f0 0f b1 
[14532.484940] NMI backtrace for cpu 4
[14532.484941] CPU: 4 PID: 18856 Comm: linux Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.484942] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.484944] task: ffff880134960e00 ti: ffff8801e6268000 task.ti: ffff8801e6268000
[14532.484945] RIP: 0010:[<ffffffff810c6a20>]  [<ffffffff810c6a20>] native_queued_spin_lock_slowpath+0x160/0x170
[14532.484946] RSP: 0018:ffff880f46d03de0  EFLAGS: 00000002
[14532.484947] RAX: 0000000000000101 RBX: 0000000000000046 RCX: 0000000000000001
[14532.484949] RDX: 0000000000000101 RSI: 0000000000000001 RDI: ffff88002013e180
[14532.484950] RBP: ffff880f46d03de0 R08: 0000000000000101 R09: 0000000000004000
[14532.484951] R10: 0000000000000001 R11: 0000000000007ffe R12: ffffffff81ec7ba0
[14532.484952] R13: 000000000000001d R14: 0000000000020001 R15: ffffffff81d261ad
[14532.484954] FS:  00007fe7f7517740(0000) GS:ffff880f46d00000(0000) knlGS:0000000000000000
[14532.484955] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.484956] CR2: 00007fb3678629f0 CR3: 00000001b7f20000 CR4: 00000000001406e0
[14532.484957] Stack:
[14532.484958]  ffff880f46d03df0 ffffffff81184217 ffff880f46d03e08 ffffffff8180f357
[14532.484960]  ffff88002013e180 ffff880f46d03e38 ffffffff81214d75 0000000000000406
[14532.484961]  ffffffff81ec7ba0 0000000000000018 ffffffff81ec7bf0 ffff880f46d03e88
[14532.484962] Call Trace:
[14532.484963]  <IRQ> .d [<ffffffff81184217>] queued_spin_lock_slowpath+0xb/0xf
[14532.484964]  [<ffffffff8180f357>] _raw_spin_lock_irqsave+0x37/0x40
[14532.484966]  [<ffffffff81214d75>] kill_fasync+0x35/0x90
[14532.484967]  [<ffffffff81506020>] credit_entropy_bits+0x250/0x380
[14532.484968]  [<ffffffff8150649d>] ? add_interrupt_randomness+0x16d/0x1c0
[14532.484969]  [<ffffffff8150649d>] add_interrupt_randomness+0x16d/0x1c0
[14532.484970]  [<ffffffff810d6587>] handle_irq_event_percpu+0xa7/0x1d0
[14532.484972]  [<ffffffff810d66ee>] handle_irq_event+0x3e/0x60
[14532.484973]  [<ffffffff810d9b0c>] handle_edge_irq+0x9c/0x150
[14532.484974]  [<ffffffff810300c0>] handle_irq+0x20/0x30
[14532.484975]  [<ffffffff81811f5d>] do_IRQ+0x4d/0xd0
[14532.484976]  [<ffffffff81810042>] common_interrupt+0x82/0x82
[14532.484977]  <EOI> .d [<ffffffff810c69cd>] ? native_queued_spin_lock_slowpath+0x10d/0x170
[14532.484979]  [<ffffffff81184364>] queued_spin_lock_slowpath+0xb/0xf
[14532.484980]  [<ffffffff810c7f96>] queued_read_lock_slowpath+0x76/0x80
[14532.484981]  [<ffffffff8180f293>] _raw_read_lock+0x23/0x30
[14532.484982]  [<ffffffff8108842e>] ptrace_check_attach+0x1e/0x140
[14532.484983]  [<ffffffff8108914e>] SyS_ptrace+0x8e/0x110
[14532.484985]  [<ffffffff8180f576>] entry_SYSCALL_64_fastpath+0x16/0x75
[14532.484986] Code: 8b 01 48 85 c0 75 0a f3 90 48 8b 01 48 85 c0 74 f6 c7 40 08 01 00 00 00 e9 61 ff ff ff 83 fa 01 75 07 e9 c2 fe ff ff f3 90 8b 07 <84> c0 75 f8 b8 01 00 00 00 66 89 07 5d c3 66 90 0f 1f 44 00 00 
[14532.484987] NMI backtrace for cpu 5
[14532.484989] CPU: 5 PID: 23953 Comm: linux Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.484990] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.484991] task: ffff88022eec6200 ti: ffff88015078c000 task.ti: ffff88015078c000
[14532.484993] RIP: 0010:[<ffffffff810c69cd>]  [<ffffffff810c69cd>] native_queued_spin_lock_slowpath+0x10d/0x170
[14532.484994] RSP: 0018:ffff880f46d43de0  EFLAGS: 00000046
[14532.484995] RAX: 0000000000000000 RBX: 0000000000000046 RCX: ffff880f46d57910
[14532.484996] RDX: ffff880f46e97900 RSI: 0000000000190000 RDI: ffff88016bc69c30
[14532.484997] RBP: ffff880f46d43de0 R08: 0000000000000101 R09: 0000000000000000
[14532.484999] R10: 000000000000001c R11: 0000000000007ffe R12: 0000000000000046
[14532.485000] R13: 000000000000001d R14: 0000000000020001 R15: ffffffff81d261ad
[14532.485001] FS:  00007fe848cd2740(0000) GS:ffff880f46d40000(0000) knlGS:0000000000000000
[14532.485002] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.485004] CR2: 0000000040242008 CR3: 00000001a138a000 CR4: 00000000001406e0
[14532.485005] Stack:
[14532.485006]  ffff880f46d43df0 ffffffff81184217 ffff880f46d43e08 ffffffff8180f357
[14532.485007]  ffff88016bc69c30 ffff880f46d43e38 ffffffff81214d75 0000000000000404
[14532.485008]  ffffffff81ec7ba0 0000000000000013 ffffffff81ec7bf0 ffff880f46d43e88
[14532.485009] Call Trace:
[14532.485011]  <IRQ> .d [<ffffffff81184217>] queued_spin_lock_slowpath+0xb/0xf
[14532.485012]  [<ffffffff8180f357>] _raw_spin_lock_irqsave+0x37/0x40
[14532.485013]  [<ffffffff81214d75>] kill_fasync+0x35/0x90
[14532.485014]  [<ffffffff81506020>] credit_entropy_bits+0x250/0x380
[14532.485015]  [<ffffffff8150649d>] ? add_interrupt_randomness+0x16d/0x1c0
[14532.485017]  [<ffffffff8150649d>] add_interrupt_randomness+0x16d/0x1c0
[14532.485018]  [<ffffffff810d6587>] handle_irq_event_percpu+0xa7/0x1d0
[14532.485019]  [<ffffffff810d66ee>] handle_irq_event+0x3e/0x60
[14532.485020]  [<ffffffff810d9b0c>] handle_edge_irq+0x9c/0x150
[14532.485021]  [<ffffffff810300c0>] handle_irq+0x20/0x30
[14532.485023]  [<ffffffff81811f5d>] do_IRQ+0x4d/0xd0
[14532.485024]  [<ffffffff81810042>] common_interrupt+0x82/0x82
[14532.485025]  <EOI> .d [<ffffffff810c69cd>] ? native_queued_spin_lock_slowpath+0x10d/0x170
[14532.485026]  [<ffffffff81184364>] queued_spin_lock_slowpath+0xb/0xf
[14532.485027]  [<ffffffff810c7f96>] queued_read_lock_slowpath+0x76/0x80
[14532.485028]  [<ffffffff8180f293>] _raw_read_lock+0x23/0x30
[14532.485030]  [<ffffffff8108842e>] ptrace_check_attach+0x1e/0x140
[14532.485031]  [<ffffffff8108914e>] SyS_ptrace+0x8e/0x110
[14532.485032]  [<ffffffff8180f576>] entry_SYSCALL_64_fastpath+0x16/0x75
[14532.485034] Code: 12 48 c1 ea 0c 83 e8 01 83 e2 30 48 98 48 81 c2 00 79 01 00 48 03 14 c5 c0 a0 f3 81 48 89 0a 8b 41 08 85 c0 75 0d f3 90 8b 41 08 <85> c0 74 f7 eb 02 f3 90 8b 17 66 85 d2 75 f7 39 f2 66 90 75 0f 
[14532.485035] NMI backtrace for cpu 6
[14532.485036] CPU: 6 PID: 25710 Comm: vlan-network-in Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.485037] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.485039] task: ffff88010a9c0e00 ti: ffff8801f61fc000 task.ti: ffff8801f61fc000
[14532.485040] RIP: 0010:[<ffffffff810c7ee9>]  [<ffffffff810c7ee9>] queued_write_lock_slowpath+0x59/0x90
[14532.485041] RSP: 0018:ffff8801f61ffd88  EFLAGS: 00000006
[14532.485042] RAX: 0000000000000101 RBX: ffffffff81e0b080 RCX: 0000000000000009
[14532.485044] RDX: 00000000000000ff RSI: ffff8801f61ffd58 RDI: ffffffff81e0b080
[14532.485045] RBP: ffff8801f61ffd98 R08: 000000000000000a R09: 000000000000fffa
[14532.485046] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff81e0b084
[14532.485047] R13: ffff8801f61ffed0 R14: 0000000000000010 R15: ffff88013f8b0000
[14532.485049] FS:  00007fe0a654d740(0000) GS:ffff880f46d80000(0000) knlGS:0000000000000000
[14532.485050] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.485051] CR2: 0000564765888d20 CR3: 0000000174cfa000 CR4: 00000000001406e0
[14532.485052] Stack:
[14532.485053]  00007fffffffeffd ffff88013f8b0000 ffff8801f61ffda8 ffffffff8180f135
[14532.485054]  ffff8801f61ffe00 ffffffff8107fe5f 000000000000649c ffff8801f61ffe00
[14532.485056]  ffffffff810ae9a1 0000000000000000 00007fffffffeffd ffff88013f8b0000
[14532.485057] Call Trace:
[14532.485058]  [<ffffffff8180f135>] _raw_write_lock_irq+0x25/0x30
[14532.485059]  [<ffffffff8107fe5f>] release_task+0x3f/0x460
[14532.485060]  [<ffffffff810ae9a1>] ? thread_group_cputime_adjusted+0x41/0x50
[14532.485062]  [<ffffffff81080822>] wait_consider_task+0x5a2/0xaf0
[14532.485063]  [<ffffffff8180b6b9>] ? __schedule+0x359/0x980
[14532.485064]  [<ffffffff81080e5f>] do_wait+0xef/0x230
[14532.485065]  [<ffffffff81081fc4>] SyS_wait4+0x64/0xc0
[14532.485066]  [<ffffffff8107fd30>] ? task_stopped_code+0x50/0x50
[14532.485068]  [<ffffffff8180f576>] entry_SYSCALL_64_fastpath+0x16/0x75
[14532.485069] Code: f0 0f b1 13 85 c0 74 31 ba 01 00 00 00 eb 02 f3 90 0f b6 03 84 c0 75 f7 f0 0f b0 13 84 c0 75 ef ba ff 00 00 00 eb 02 f3 90 8b 03 <83> f8 01 75 f7 f0 0f b1 13 83 f8 01 75 ee 4c 89 e7 c6 07 00 0f 
[14532.485070] NMI backtrace for cpu 7
[14532.485071] CPU: 7 PID: 19901 Comm: java Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.485073] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.485074] task: ffff880de625d400 ti: ffff8807d7e78000 task.ti: ffff8807d7e78000
[14532.485075] RIP: 0010:[<ffffffff810c69ca>]  [<ffffffff810c69ca>] native_queued_spin_lock_slowpath+0x10a/0x170
[14532.485077] RSP: 0000:ffff880f46dc3de0  EFLAGS: 00000046
[14532.485078] RAX: 0000000000000000 RBX: 0000000000000046 RCX: ffff880f46dd7900
[14532.485079] RDX: ffff880f46e17900 RSI: 0000000000200000 RDI: ffff88016bc69c30
[14532.485080] RBP: ffff880f46dc3de0 R08: 0000000000000101 R09: 0000000000000000
[14532.485082] R10: 000000000000001c R11: 0000000000007ffe R12: 0000000000000046
[14532.485083] R13: 000000000000001d R14: 0000000000020001 R15: ffffffff81d261ad
[14532.485084] FS:  00007f0c955fe700(0000) GS:ffff880f46dc0000(0000) knlGS:0000000000000000
[14532.485085] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.485087] CR2: 00007f0a5960c000 CR3: 0000000bdeed2000 CR4: 00000000001406e0
[14532.485088] Stack:
[14532.485089]  ffff880f46dc3df0 ffffffff81184217 ffff880f46dc3e08 ffffffff8180f357
[14532.485090]  ffff88016bc69c30 ffff880f46dc3e38 ffffffff81214d75 0000000000000406
[14532.485091]  ffffffff81ec7ba0 0000000000000017 ffffffff81ec7bf0 ffff880f46dc3e88
[14532.485092] Call Trace:
[14532.485094]  <IRQ> .d [<ffffffff81184217>] queued_spin_lock_slowpath+0xb/0xf
[14532.485095]  [<ffffffff8180f357>] _raw_spin_lock_irqsave+0x37/0x40
[14532.485096]  [<ffffffff81214d75>] kill_fasync+0x35/0x90
[14532.485097]  [<ffffffff81506020>] credit_entropy_bits+0x250/0x380
[14532.485098]  [<ffffffff8150649d>] ? add_interrupt_randomness+0x16d/0x1c0
[14532.485100]  [<ffffffff8150649d>] add_interrupt_randomness+0x16d/0x1c0
[14532.485101]  [<ffffffff810d6587>] handle_irq_event_percpu+0xa7/0x1d0
[14532.485102]  [<ffffffff810d66ee>] handle_irq_event+0x3e/0x60
[14532.485103]  [<ffffffff810d9b0c>] handle_edge_irq+0x9c/0x150
[14532.485105]  [<ffffffff810300c0>] handle_irq+0x20/0x30
[14532.485106]  [<ffffffff81811f5d>] do_IRQ+0x4d/0xd0
[14532.485107]  [<ffffffff81810042>] common_interrupt+0x82/0x82
[14532.485108]  <EOI> .dCode: c2 c1 e8 12 48 c1 ea 0c 83 e8 01 83 e2 30 48 98 48 81 c2 00 79 01 00 48 03 14 c5 c0 a0 f3 81 48 89 0a 8b 41 08 85 c0 75 0d f3 90 <8b> 41 08 85 c0 74 f7 eb 02 f3 90 8b 17 66 85 d2 75 f7 39 f2 66 
[14532.485110] NMI backtrace for cpu 8
[14532.485111] CPU: 8 PID: 22900 Comm: gunicorn: worke Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.485112] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.485113] task: ffff88016c745400 ti: ffff880174e74000 task.ti: ffff880174e74000
[14532.485115] RIP: 0010:[<ffffffff810c69ca>]  [<ffffffff810c69ca>] native_queued_spin_lock_slowpath+0x10a/0x170
[14532.485116] RSP: 0018:ffff880f46e03de0  EFLAGS: 00000046
[14532.485117] RAX: 0000000000000000 RBX: 0000000000000046 RCX: ffff880f46e17900
[14532.485119] RDX: ffff880f46c57900 RSI: 0000000000240000 RDI: ffff88016bc69c30
[14532.485120] RBP: ffff880f46e03de0 R08: 0000000000000101 R09: 0000000000000000
[14532.485121] R10: 000000000000001c R11: 0000000000007ffe R12: 0000000000000046
[14532.485122] R13: 000000000000001d R14: 0000000000020001 R15: ffffffff81d261ad
[14532.485124] FS:  00007f3893e31740(0000) GS:ffff880f46e00000(0000) knlGS:0000000000000000
[14532.485125] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.485126] CR2: 0000000003402013 CR3: 00000001a87a4000 CR4: 00000000001406e0
[14532.485127] Stack:
[14532.485128]  ffff880f46e03df0 ffffffff81184217 ffff880f46e03e08 ffffffff8180f357
[14532.485129]  ffff88016bc69c30 ffff880f46e03e38 ffffffff81214d75 0000000000000405
[14532.485131]  ffffffff81ec7ba0 0000000000000016 ffffffff81ec7bf0 ffff880f46e03e88
[14532.485132] Call Trace:
[14532.485133]  <IRQ> .d [<ffffffff81184217>] queued_spin_lock_slowpath+0xb/0xf
[14532.485134]  [<ffffffff8180f357>] _raw_spin_lock_irqsave+0x37/0x40
[14532.485135]  [<ffffffff81214d75>] kill_fasync+0x35/0x90
[14532.485137]  [<ffffffff81506020>] credit_entropy_bits+0x250/0x380
[14532.485138]  [<ffffffff8150649d>] ? add_interrupt_randomness+0x16d/0x1c0
[14532.485139]  [<ffffffff8150649d>] add_interrupt_randomness+0x16d/0x1c0
[14532.485140]  [<ffffffff810d6587>] handle_irq_event_percpu+0xa7/0x1d0
[14532.485141]  [<ffffffff810d66ee>] handle_irq_event+0x3e/0x60
[14532.485143]  [<ffffffff810d9b0c>] handle_edge_irq+0x9c/0x150
[14532.485144]  [<ffffffff810300c0>] handle_irq+0x20/0x30
[14532.485145]  [<ffffffff81811f5d>] do_IRQ+0x4d/0xd0
[14532.485146]  [<ffffffff81810042>] common_interrupt+0x82/0x82
[14532.485147]  <EOI> .d [<ffffffff81121938>] ? audit_filter_syscall+0x88/0xd0
[14532.485149]  [<ffffffff81122559>] __audit_syscall_exit+0x239/0x270
[14532.485150]  [<ffffffff810797c5>] syscall_slow_exit_work+0x3f/0xbd
[14532.485151]  [<ffffffff81003a64>] syscall_return_slowpath+0x44/0x60
[14532.485152]  [<ffffffff8180f6d8>] int_ret_from_sys_call+0x25/0x8f
[14532.485154] Code: c2 c1 e8 12 48 c1 ea 0c 83 e8 01 83 e2 30 48 98 48 81 c2 00 79 01 00 48 03 14 c5 c0 a0 f3 81 48 89 0a 8b 41 08 85 c0 75 0d f3 90 <8b> 41 08 85 c0 74 f7 eb 02 f3 90 8b 17 66 85 d2 75 f7 39 f2 66 
[14532.485155] NMI backtrace for cpu 10
[14532.485156] CPU: 10 PID: 23871 Comm: linux Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.485158] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.485159] task: ffff880118e5d400 ti: ffff8801b6c9c000 task.ti: ffff8801b6c9c000
[14532.485160] RIP: 0010:[<ffffffff810c69cd>]  [<ffffffff810c69cd>] native_queued_spin_lock_slowpath+0x10d/0x170
[14532.485161] RSP: 0018:ffff880f46e83de0  EFLAGS: 00000046
[14532.485163] RAX: 0000000000000000 RBX: 0000000000000046 RCX: ffff880f46e97900
[14532.485164] RDX: ffff880f46f17900 RSI: 00000000002c0000 RDI: ffff88016bc69c30
[14532.485165] RBP: ffff880f46e83de0 R08: 0000000000000101 R09: 0000000000000000
[14532.485166] R10: 000000000000001c R11: 0000000000007ffe R12: 0000000000000046
[14532.485168] R13: 000000000000001d R14: 0000000000020001 R15: ffffffff81d261ad
[14532.485169] FS:  00007f6516e5f740(0000) GS:ffff880f46e80000(0000) knlGS:0000000000000000
[14532.485170] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.485171] CR2: 00000000620a3000 CR3: 000000024596d000 CR4: 00000000001406e0
[14532.485172] Stack:
[14532.485174]  ffff880f46e83df0 ffffffff81184217 ffff880f46e83e08 ffffffff8180f357
[14532.485175]  ffff88016bc69c30 ffff880f46e83e38 ffffffff81214d75 0000000000000403
[14532.485176]  ffffffff81ec7ba0 0000000000000012 ffffffff81ec7bf0 ffff880f46e83e88
[14532.485177] Call Trace:
[14532.485178]  <IRQ> .d [<ffffffff81184217>] queued_spin_lock_slowpath+0xb/0xf
[14532.485179]  [<ffffffff8180f357>] _raw_spin_lock_irqsave+0x37/0x40
[14532.485181]  [<ffffffff81214d75>] kill_fasync+0x35/0x90
[14532.485182]  [<ffffffff81506020>] credit_entropy_bits+0x250/0x380
[14532.485183]  [<ffffffff8150649d>] ? add_interrupt_randomness+0x16d/0x1c0
[14532.485184]  [<ffffffff8150649d>] add_interrupt_randomness+0x16d/0x1c0
[14532.485185]  [<ffffffff810d6587>] handle_irq_event_percpu+0xa7/0x1d0
[14532.485187]  [<ffffffff810d66ee>] handle_irq_event+0x3e/0x60
[14532.485188]  [<ffffffff810d9b0c>] handle_edge_irq+0x9c/0x150
[14532.485189]  [<ffffffff810300c0>] handle_irq+0x20/0x30
[14532.485190]  [<ffffffff81811f5d>] do_IRQ+0x4d/0xd0
[14532.485191]  [<ffffffff81810042>] common_interrupt+0x82/0x82
[14532.485193]  <EOI> .d [<ffffffff810a8f96>] ? wait_task_inactive+0x46/0x200
[14532.485194]  [<ffffffff811222cf>] ? __audit_syscall_entry+0xaf/0x100
[14532.485195]  [<ffffffff81088471>] ptrace_check_attach+0x61/0x140
[14532.485196]  [<ffffffff8108914e>] SyS_ptrace+0x8e/0x110
[14532.485197]  [<ffffffff8180f576>] entry_SYSCALL_64_fastpath+0x16/0x75
[14532.485199] Code: 12 48 c1 ea 0c 83 e8 01 83 e2 30 48 98 48 81 c2 00 79 01 00 48 03 14 c5 c0 a0 f3 81 48 89 0a 8b 41 08 85 c0 75 0d f3 90 8b 41 08 <85> c0 74 f7 eb 02 f3 90 8b 17 66 85 d2 75 f7 39 f2 66 90 75 0f 
[14532.485200] NMI backtrace for cpu 11
[14532.485201] CPU: 11 PID: 25694 Comm: linux Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.485203] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.485204] task: ffff880b3487c600 ti: ffff880189200000 task.ti: ffff880189200000
[14532.485205] RIP: 0010:[<ffffffff810c69cd>]  [<ffffffff810c69cd>] native_queued_spin_lock_slowpath+0x10d/0x170
[14532.485207] RSP: 0000:ffff880f46ec3de0  EFLAGS: 00000046
[14532.485208] RAX: 0000000000000000 RBX: 0000000000000046 RCX: ffff880f46ed7910
[14532.485209] RDX: ffff880f46d57910 RSI: 0000000000310000 RDI: ffff88016bc69c30
[14532.485210] RBP: ffff880f46ec3de0 R08: 0000000000000101 R09: 0000000000000000
[14532.485211] R10: 000000000000001c R11: 0000000000007ffe R12: 0000000000000046
[14532.485213] R13: 000000000000001d R14: 0000000000020001 R15: ffffffff81d261ad
[14532.485214] FS:  00007f183c70f740(0000) GS:ffff880f46ec0000(0000) knlGS:0000000000000000
[14532.485215] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.485216] CR2: 00007fc7e0ac1ce0 CR3: 0000000174cbe000 CR4: 00000000001406e0
[14532.485217] Stack:
[14532.485219]  ffff880f46ec3df0 ffffffff81184217 ffff880f46ec3e08 ffffffff8180f357
[14532.485220]  ffff88016bc69c30 ffff880f46ec3e38 ffffffff81214d75 0000000000000404
[14532.485221]  ffffffff81ec7ba0 0000000000000014 ffffffff81ec7bf0 ffff880f46ec3e88
[14532.485222] Call Trace:
[14532.485223]  <IRQ> .d [<ffffffff81184217>] queued_spin_lock_slowpath+0xb/0xf
[14532.485225]  [<ffffffff8180f357>] _raw_spin_lock_irqsave+0x37/0x40
[14532.485226]  [<ffffffff81214d75>] kill_fasync+0x35/0x90
[14532.485227]  [<ffffffff81506020>] credit_entropy_bits+0x250/0x380
[14532.485228]  [<ffffffff8150649d>] ? add_interrupt_randomness+0x16d/0x1c0
[14532.485229]  [<ffffffff8150649d>] add_interrupt_randomness+0x16d/0x1c0
[14532.485230]  [<ffffffff810d6587>] handle_irq_event_percpu+0xa7/0x1d0
[14532.485232]  [<ffffffff810d66ee>] handle_irq_event+0x3e/0x60
[14532.485233]  [<ffffffff810d9b0c>] handle_edge_irq+0x9c/0x150
[14532.485234]  [<ffffffff810300c0>] handle_irq+0x20/0x30
[14532.485235]  [<ffffffff81811f5d>] do_IRQ+0x4d/0xd0
[14532.485236]  [<ffffffff81810042>] common_interrupt+0x82/0x82
[14532.485238]  <EOI> .d [<ffffffff8108a4a3>] ? __sigqueue_free.part.14+0x33/0x40
[14532.485239]  [<ffffffff810c69ca>] ? native_queued_spin_lock_slowpath+0x10a/0x170
[14532.485240]  [<ffffffff81184364>] queued_spin_lock_slowpath+0xb/0xf
[14532.485241]  [<ffffffff810c7f96>] queued_read_lock_slowpath+0x76/0x80
[14532.485242]  [<ffffffff8180f293>] _raw_read_lock+0x23/0x30
[14532.485244]  [<ffffffff8108bf00>] ptrace_stop+0xd0/0x270
[14532.485245]  [<ffffffff8108d7d4>] get_signal+0x3e4/0x610
[14532.485246]  [<ffffffff8108b29a>] ? signal_wake_up_state+0x2a/0x30
[14532.485247]  [<ffffffff8102d4a8>] do_signal+0x28/0x6c0
[14532.485248]  [<ffffffff8108b936>] ? __send_signal+0x176/0x460
[14532.485250]  [<ffffffff8108c469>] ? force_sig_info+0xc9/0xe0
[14532.485251]  [<ffffffff8107989c>] exit_to_usermode_loop+0x59/0xa2
[14532.485252]  [<ffffffff81003a16>] prepare_exit_to_usermode+0x26/0x30
[14532.485253]  [<ffffffff81810065>] retint_user+0x8/0x13
[14532.485255] Code: 12 48 c1 ea 0c 83 e8 01 83 e2 30 48 98 48 81 c2 00 79 01 00 48 03 14 c5 c0 a0 f3 81 48 89 0a 8b 41 08 85 c0 75 0d f3 90 8b 41 08 <85> c0 74 f7 eb 02 f3 90 8b 17 66 85 d2 75 f7 39 f2 66 90 75 0f 
[14532.485256] NMI backtrace for cpu 12
[14532.485257] CPU: 12 PID: 25639 Comm: python Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.485259] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.485260] task: ffff88012fbc8e00 ti: ffff880121b60000 task.ti: ffff880121b60000
[14532.485261] RIP: 0010:[<ffffffff810c69cd>]  [<ffffffff810c69cd>] native_queued_spin_lock_slowpath+0x10d/0x170
[14532.485262] RSP: 0000:ffff880f46f03de0  EFLAGS: 00000046
[14532.485264] RAX: 0000000000000000 RBX: 0000000000000046 RCX: ffff880f46f17900
[14532.485265] RDX: ffff880f46cd7900 RSI: 0000000000340000 RDI: ffff88016bc69c30
[14532.485266] RBP: ffff880f46f03de0 R08: 0000000000000101 R09: 0000000000000000
[14532.485267] R10: 000000000000001c R11: 0000000000007ffe R12: 0000000000000046
[14532.485269] R13: 000000000000001d R14: 0000000000020001 R15: ffffffff81d261ad
[14532.485270] FS:  00007f4d44461740(0000) GS:ffff880f46f00000(0000) knlGS:0000000000000000
[14532.485271] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.485272] CR2: 0000000001409678 CR3: 00000001a536d000 CR4: 00000000001406e0
[14532.485273] Stack:
[14532.485274]  ffff880f46f03df0 ffffffff81184217 ffff880f46f03e08 ffffffff8180f357
[14532.485276]  ffff88016bc69c30 ffff880f46f03e38 ffffffff81214d75 0000000000000403
[14532.485277]  ffffffff81ec7ba0 0000000000000011 ffffffff81ec7bf0 ffff880f46f03e88
[14532.485278] Call Trace:
[14532.485279]  <IRQ> .d [<ffffffff81184217>] queued_spin_lock_slowpath+0xb/0xf
[14532.485280]  [<ffffffff8180f357>] _raw_spin_lock_irqsave+0x37/0x40
[14532.485282]  [<ffffffff81214d75>] kill_fasync+0x35/0x90
[14532.485283]  [<ffffffff81506020>] credit_entropy_bits+0x250/0x380
[14532.485284]  [<ffffffff8150649d>] ? add_interrupt_randomness+0x16d/0x1c0
[14532.485285]  [<ffffffff8150649d>] add_interrupt_randomness+0x16d/0x1c0
[14532.485287]  [<ffffffff810d6587>] handle_irq_event_percpu+0xa7/0x1d0
[14532.485288]  [<ffffffff810d66ee>] handle_irq_event+0x3e/0x60
[14532.485289]  [<ffffffff810d9b0c>] handle_edge_irq+0x9c/0x150
[14532.485290]  [<ffffffff810300c0>] handle_irq+0x20/0x30
[14532.485291]  [<ffffffff81811f5d>] do_IRQ+0x4d/0xd0
[14532.485292]  [<ffffffff81810042>] common_interrupt+0x82/0x82
[14532.485294]  <EOI> .dCode: 12 48 c1 ea 0c 83 e8 01 83 e2 30 48 98 48 81 c2 00 79 01 00 48 03 14 c5 c0 a0 f3 81 48 89 0a 8b 41 08 85 c0 75 0d f3 90 8b 41 08 <85> c0 74 f7 eb 02 f3 90 8b 17 66 85 d2 75 f7 39 f2 66 90 75 0f 
[14532.485295] NMI backtrace for cpu 13
[14532.485296] CPU: 13 PID: 25759 Comm: sh Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.485298] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.485299] task: ffff880a55b4aa00 ti: ffff88017f670000 task.ti: ffff88017f670000
[14532.485300] RIP: 0010:[<ffffffff810c6a20>]  [<ffffffff810c6a20>] native_queued_spin_lock_slowpath+0x160/0x170
[14532.485301] RSP: 0018:ffff88017f673b80  EFLAGS: 00000002
[14532.485303] RAX: 0000000000040101 RBX: ffffffff81e0b080 RCX: 0000000000000001
[14532.485304] RDX: 0000000000000101 RSI: 0000000000000001 RDI: ffffffff81e0b084
[14532.485305] RBP: ffff88017f673b80 R08: 0000000000000101 R09: 0000000000000000
[14532.485306] R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff81e0b084
[14532.485308] R13: 0000000000000007 R14: 0000000000020002 R15: ffff880e620fc200
[14532.485309] FS:  0000000000000000(0000) GS:ffff880f46f40000(0000) knlGS:0000000000000000
[14532.485310] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.485311] CR2: 00007fffc9078509 CR3: 00000001a6b52000 CR4: 00000000001406e0
[14532.485312] Stack:
[14532.485314]  ffff88017f673b90 ffffffff81184364 ffff88017f673bb0 ffffffff810c7f96
[14532.485315]  ffff880ed02f9c78 0000000000000246 ffff88017f673bc0 ffffffff8180f293
[14532.485316]  ffff88017f673c08 ffffffff81214c82 ffffffff00000000 0000000100000000
[14532.485317] Call Trace:
[14532.485318]  [<ffffffff81184364>] queued_spin_lock_slowpath+0xb/0xf
[14532.485319]  [<ffffffff810c7f96>] queued_read_lock_slowpath+0x76/0x80
[14532.485321]  [<ffffffff8180f293>] _raw_read_lock+0x23/0x30
[14532.485322]  [<ffffffff81214c82>] send_sigio+0x52/0x110
[14532.485323]  [<ffffffff81214da0>] kill_fasync+0x60/0x90
[14532.485324]  [<ffffffff81505baa>] account+0x13a/0x190
[14532.485325]  [<ffffffff81068f62>] ? do_page_fault+0x22/0x30
[14532.485326]  [<ffffffff8150831e>] extract_entropy+0x6e/0x150
[14532.485328]  [<ffffffff81319430>] ? create_elf_tables+0xa1/0x50d
[14532.485329]  [<ffffffff815086d6>] get_random_bytes+0x36/0x90
[14532.485330]  [<ffffffff81319430>] create_elf_tables+0xa1/0x50d
[14532.485331]  [<ffffffff8125cdbd>] load_elf_binary+0xb0d/0x10f0
[14532.485332]  [<ffffffff81208d5e>] search_binary_handler+0x9e/0x1e0
[14532.485334]  [<ffffffff8120a23f>] do_execveat_common.isra.31+0x56f/0x730
[14532.485335]  [<ffffffff8120a66a>] SyS_execve+0x3a/0x50
[14532.485336]  [<ffffffff8180f815>] stub_execve+0x5/0x5
[14532.485337]  [<ffffffff8180f576>] ? entry_SYSCALL_64_fastpath+0x16/0x75
[14532.485339] Code: 8b 01 48 85 c0 75 0a f3 90 48 8b 01 48 85 c0 74 f6 c7 40 08 01 00 00 00 e9 61 ff ff ff 83 fa 01 75 07 e9 c2 fe ff ff f3 90 8b 07 <84> c0 75 f8 b8 01 00 00 00 66 89 07 5d c3 66 90 0f 1f 44 00 00 
[14532.485340] NMI backtrace for cpu 14
[14532.485341] CPU: 14 PID: 23868 Comm: linux Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.485342] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.485344] task: ffff880efdf34600 ti: ffff88015e0e8000 task.ti: ffff88015e0e8000
[14532.485345] RIP: 0010:[<ffffffff810c69cd>]  [<ffffffff810c69cd>] native_queued_spin_lock_slowpath+0x10d/0x170
[14532.485346] RSP: 0018:ffff88015e0ebc20  EFLAGS: 00000046
[14532.485347] RAX: 0000000000000000 RBX: ffffffff81e0b080 RCX: ffff880f46f97900
[14532.485349] RDX: ffff880f46ed7900 RSI: 00000000003c0000 RDI: ffffffff81e0b084
[14532.485350] RBP: ffff88015e0ebc20 R08: 0000000000000101 R09: 0000000000000000
[14532.485351] R10: ffff880f06803600 R11: ffff88016c6b0c00 R12: ffffffff81e0b084
[14532.485352] R13: 0000000000000006 R14: 0000000000020001 R15: ffff88007895d700
[14532.485354] FS:  00007fd8dbf49740(0000) GS:ffff880f46f80000(0000) knlGS:0000000000000000
[14532.485355] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.485356] CR2: 000000009f0ad000 CR3: 00000001337bb000 CR4: 00000000001406e0
[14532.485357] Stack:
[14532.485358]  ffff88015e0ebc30 ffffffff81184364 ffff88015e0ebc50 ffffffff810c7f96
[14532.485359]  ffff880efa3ad578 0000000000000246 ffff88015e0ebc60 ffffffff8180f293
[14532.485361]  ffff88015e0ebca8 ffffffff81214c82 ffffffff00000000 0000000100000000
[14532.485362] Call Trace:
[14532.485363]  [<ffffffff81184364>] queued_spin_lock_slowpath+0xb/0xf
[14532.485364]  [<ffffffff810c7f96>] queued_read_lock_slowpath+0x76/0x80
[14532.485365]  [<ffffffff8180f293>] _raw_read_lock+0x23/0x30
[14532.485366]  [<ffffffff81214c82>] send_sigio+0x52/0x110
[14532.485368]  [<ffffffff81214da0>] kill_fasync+0x60/0x90
[14532.485369]  [<ffffffff816ecb0b>] sock_wake_async+0x4b/0x80
[14532.485370]  [<ffffffff816f0e6b>] sock_def_readable+0x5b/0x60
[14532.485371]  [<ffffffff817ab27e>] unix_stream_sendmsg+0x1be/0x3a0
[14532.485372]  [<ffffffff816edaf8>] sock_sendmsg+0x38/0x50
[14532.485374]  [<ffffffff816edb88>] sock_write_iter+0x78/0xd0
[14532.485375]  [<ffffffff81202288>] new_sync_write+0x88/0xb0
[14532.485376]  [<ffffffff812022d7>] __vfs_write+0x27/0x40
[14532.485377]  [<ffffffff812028e2>] vfs_write+0xa2/0x1a0
[14532.485378]  [<ffffffff81003176>] ? do_audit_syscall_entry+0x66/0x70
[14532.485380]  [<ffffffff81203606>] SyS_write+0x46/0xa0
[14532.485381]  [<ffffffff8180f576>] entry_SYSCALL_64_fastpath+0x16/0x75
[14532.485382] Code: 12 48 c1 ea 0c 83 e8 01 83 e2 30 48 98 48 81 c2 00 79 01 00 48 03 14 c5 c0 a0 f3 81 48 89 0a 8b 41 08 85 c0 75 0d f3 90 8b 41 08 <85> c0 74 f7 eb 02 f3 90 8b 17 66 85 d2 75 f7 39 f2 66 90 75 0f 
[14532.485384] NMI backtrace for cpu 15
[14532.485385] CPU: 15 PID: 23248 Comm: linux Not tainted 4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.485386] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.485387] task: ffff88016c741c00 ti: ffff88012e944000 task.ti: ffff88012e944000
[14532.485389] RIP: 0010:[<ffffffff810c69cd>]  [<ffffffff810c69cd>] native_queued_spin_lock_slowpath+0x10d/0x170
[14532.485390] RSP: 0018:ffff88012e947e28  EFLAGS: 00000246
[14532.485391] RAX: 0000000000000000 RBX: ffffffff81e0b080 RCX: ffff880f46fd7900
[14532.485392] RDX: ffff880f46f97900 RSI: 0000000000400000 RDI: ffffffff81e0b084
[14532.485394] RBP: ffff88012e947e28 R08: 0000000000000101 R09: 00000d3186ca3e50
[14532.485395] R10: 00000000000022d0 R11: 0000000000000000 R12: ffffffff81e0b084
[14532.485396] R13: ffff88016c741c00 R14: ffff88016c741c00 R15: ffff88016c741bf0
[14532.485397] FS:  00007f5e5d4eb740(0000) GS:ffff880f46fc0000(0000) knlGS:0000000000000000
[14532.485399] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[14532.485400] CR2: 00007f0c499248f2 CR3: 000000021ba65000 CR4: 00000000001406e0
[14532.485401] Stack:
[14532.485402]  ffff88012e947e38 ffffffff81184364 ffff88012e947e58 ffffffff810c7f96
[14532.485403]  ffff88012e947ed0 ffff88016c742090 ffff88012e947e68 ffffffff8180f293
[14532.485405]  ffff88012e947ec0 ffffffff81080e23 ffff88012e947ef8 ffff88016c741c00
[14532.485406] Call Trace:
[14532.485407]  [<ffffffff81184364>] queued_spin_lock_slowpath+0xb/0xf
[14532.485408]  [<ffffffff810c7f96>] queued_read_lock_slowpath+0x76/0x80
[14532.485409]  [<ffffffff8180f293>] _raw_read_lock+0x23/0x30
[14532.485410]  [<ffffffff81080e23>] do_wait+0xb3/0x230
[14532.485412]  [<ffffffff81081fc4>] SyS_wait4+0x64/0xc0
[14532.485413]  [<ffffffff8107fd30>] ? task_stopped_code+0x50/0x50
[14532.485414]  [<ffffffff8180f576>] entry_SYSCALL_64_fastpath+0x16/0x75
[14532.485416] Code: 12 48 c1 ea 0c 83 e8 01 83 e2 30 48 98 48 81 c2 00 79 01 00 48 03 14 c5 c0 a0 f3 81 48 89 0a 8b 41 08 85 c0 75 0d f3 90 8b 41 08 <85> c0 74 f7 eb 02 f3 90 8b 17 66 85 d2 75 f7 39 f2 66 90 75 0f 
[14532.485417] Kernel panic - not syncing: softlockup: hung tasks
[14532.491253] CPU: 9 PID: 23890 Comm: linux Tainted: G             L  4.4.0-104-generic #127~14.04.1-Ubuntu
[14532.500827] Hardware name: Supermicro PIO-228TR-HT-NODE/X10DRT-H, BIOS 2.0 03/30/2016
[14532.508664]  0000000000000000 ffff880f46e43e20 ffffffff813dfcec ffffffff81cd181a
[14532.516132]  ffff880efc143800 ffff880f46e43e98 ffffffff81183c3c 0000000000000008
[14532.523602]  ffff880f46e43ea8 ffff880f46e43e48 ffff880f46e43e88 0000000000000000
[14532.531082] Call Trace:
[14532.533529]  <IRQ>  [<ffffffff813dfcec>] dump_stack+0x63/0x87
[14532.539306]  [<ffffffff81183c3c>] panic+0xc8/0x20f
[14532.544101]  [<ffffffff811342fb>] watchdog_timer_fn+0x1db/0x1f0
[14532.550021]  [<ffffffff81134120>] ? watchdog+0x40/0x40
[14532.555169]  [<ffffffff810ea983>] __hrtimer_run_queues+0xf3/0x260
[14532.561263]  [<ffffffff810eae28>] hrtimer_interrupt+0xa8/0x1a0
[14532.567106]  [<ffffffff810510e5>] local_apic_timer_interrupt+0x35/0x60
[14532.573641]  [<ffffffff8181201d>] smp_apic_timer_interrupt+0x3d/0x50
[14532.580023]  [<ffffffff818102e2>] apic_timer_interrupt+0x82/0x90
[14532.586054]  <EOI>  [<ffffffff810c69d7>] ? native_queued_spin_lock_slowpath+0x117/0x170
[14532.594125]  [<ffffffff81184364>] queued_spin_lock_slowpath+0xb/0xf
[14532.600417]  [<ffffffff810c7f96>] queued_read_lock_slowpath+0x76/0x80
[14532.606884]  [<ffffffff8180f293>] _raw_read_lock+0x23/0x30
[14532.612393]  [<ffffffff8108842e>] ptrace_check_attach+0x1e/0x140
[14532.618427]  [<ffffffff8108914e>] SyS_ptrace+0x8e/0x110
[14532.623677]  [<ffffffff8180f576>] entry_SYSCALL_64_fastpath+0x16/0x75