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From: Sasha Levin <sasha.levin@oracle.com>
To: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Dave Jones <davej@codemonkey.org.uk>,
	Davidlohr Bueso <dave@stgolabs.net>,
	jason.low2@hp.com
Subject: Re: sched: softlockups in multi_cpu_stop
Date: Fri, 06 Mar 2015 06:27:27 -0500	[thread overview]
Message-ID: <54F98F1F.3080107@oracle.com> (raw)
In-Reply-To: <54F41516.6060608@oracle.com>

I've bisected this to "locking/rwsem: Check for active lock before bailing on spinning". Relevant parties Cc'ed.

Thanks,
Sasha

On 03/02/2015 02:45 AM, Sasha Levin wrote:
> Hi all,
> 
> I'm seeing the following lockup pretty often while fuzzing with trinity:
> 
> [  880.960250] NMI watchdog: BUG: soft lockup - CPU#1 stuck for 447s! [migration/1:14]
> [  880.960700] Modules linked in:
> [  880.960700] irq event stamp: 380954
> [  880.960700] hardirqs last enabled at (380953): restore_args (arch/x86/kernel/entry_64.S:780)
> [  880.960700] hardirqs last disabled at (380954): apic_timer_interrupt (arch/x86/kernel/entry_64.S:920)
> [  880.960700] softirqs last enabled at (380952): __do_softirq (./arch/x86/include/asm/preempt.h:22 kernel/softirq.c:300)
> [  880.960700] softirqs last disabled at (380947): irq_exit (kernel/softirq.c:350 kernel/softirq.c:391)
> [  880.960700] CPU: 1 PID: 14 Comm: migration/1 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff880052cc8000 ti: ffff880052cd0000 task.ti: ffff880052cd0000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff880052cd7b78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: 0000000042506841 RCX: 1ffff1000a5992d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff880052cd7bd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff9315e211
> [  880.960700] R13: ffff880052cd7ae8 R14: ffffffff93220213 R15: ffff880052cd7ad8
> [  880.960700] FS:  0000000000000000(0000) GS:ffff880053200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000002d88fd8 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff8805d4f67728 0000000000000282
> [  880.960700]  ffff880000000000 00ff880052cc8000 ffff880052cd7bd8 dffffc0000000000
> [  880.960700]  ffff880053218440 ffff8805d4f67778 ffff8805d4f67718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] sending NMI to other CPUs:
> [  881.290044] INFO: NMI handler (arch_trigger_all_cpu_backtrace_handler) took too long to run: 1.336 msecs
> [  881.292380] INFO: NMI handler (arch_trigger_all_cpu_backtrace_handler) took too long to run: 2.083 msecs
> [  881.297603] INFO: NMI handler (arch_trigger_all_cpu_backtrace_handler) took too long to run: 7.423 msecs
> [  880.960700] NMI backtrace for cpu 0
> [  880.960700] CPU: 0 PID: 11 Comm: migration/0 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff88000d6e3000 ti: ffff88000d6f0000 task.ti: ffff88000d6f0000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff88000d6f7b78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed0007c21ee5 RCX: 1ffff10001adc8d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff88000d6f7bd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff88003e10f738 R14: 0000000000000001 R15: ffff88003e10f718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff880029000000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000002d31fb0 CR3: 000000002082c000 CR4: 00000000000007b0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff88003e10f728 0000000000000282
> [  880.960700]  ffff880000000000 00ff88000d6e3000 ffff88000d6f7bd8 dffffc0000000000
> [  880.960700]  ffff880029018440 ffff88003e10f778 ffff88003e10f718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 2
> [  880.960700] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8802ccca0000 ti: ffff88000dee8000 task.ti: ffff88000dee8000
> [  880.960700] RIP: native_safe_halt (./arch/x86/include/asm/irqflags.h:50)
> [  880.960700] RSP: 0018:ffff88000deefd38  EFLAGS: 00000282
> [  880.960700] RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000000000
> [  880.960700] RDX: 1ffffffff4115884 RSI: 0000000000000001 RDI: ffffffffa08ac420
> [  880.960700] RBP: ffff88000deefd38 R08: 0000000000000000 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffa31716b4
> [  880.960700] R13: ffff88000deeffd8 R14: 0000000000000000 R15: ffff88000deeffd8
> [  880.960700] FS:  0000000000000000(0000) GS:ffff88007d200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 00007f6baacd10f8 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffff88000deefd68 ffffffff93160774 dffffc0000000000 ffffffffa31716b4
> [  880.960700]  ffff88000deeffd8 0000000000000000 ffff88000deefd78 ffffffff931629ef
> [  880.960700]  ffff88000deefe68 ffffffff934018e0 ffff88000deefde8 ffffffff9dbf7ec5
> [  880.960700] Call Trace:
> [  880.960700] default_idle (./arch/x86/include/asm/paravirt.h:111 arch/x86/kernel/process.c:314)
> [  880.960700] arch_cpu_idle (arch/x86/kernel/process.c:306)
> [  880.960700] cpu_startup_entry (./arch/x86/include/asm/thread_info.h:162 include/linux/sched.h:2880 kernel/sched/idle.c:189 kernel/sched/idle.c:250 kernel/sched/idle.c:298)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? arch_cpu_idle_prepare (??:?)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? clockevents_register_device (kernel/time/clockevents.c:481)
> [  880.960700] start_secondary (arch/x86/kernel/smpboot.c:219)
> [  880.960700] ? set_cpu_sibling_map (arch/x86/kernel/smpboot.c:219)
> [ 880.960700] Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84
> All code
> ========
>    0:	00 00                	add    %al,(%rax)
>    2:	00 00                	add    %al,(%rax)
>    4:	00 55 48             	add    %dl,0x48(%rbp)
>    7:	89 e5                	mov    %esp,%ebp
>    9:	fa                   	cli
>    a:	5d                   	pop    %rbp
>    b:	c3                   	retq
>    c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   13:	00 00
>   15:	55                   	push   %rbp
>   16:	48 89 e5             	mov    %rsp,%rbp
>   19:	fb                   	sti
>   1a:	5d                   	pop    %rbp
>   1b:	c3                   	retq
>   1c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   23:	00 00
>   25:	55                   	push   %rbp
>   26:	48 89 e5             	mov    %rsp,%rbp
>   29:	fb                   	sti
>   2a:	f4                   	hlt
>   2b:*	5d                   	pop    %rbp		<-- trapping instruction
>   2c:	c3                   	retq
>   2d:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>   34:	00
>   35:	55                   	push   %rbp
>   36:	48 89 e5             	mov    %rsp,%rbp
>   39:	f4                   	hlt
>   3a:	5d                   	pop    %rbp
>   3b:	c3                   	retq
>   3c:	66                   	data16
>   3d:	0f                   	.byte 0xf
>   3e:	1f                   	(bad)
>   3f:	84 00                	test   %al,(%rax)
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	5d                   	pop    %rbp
>    1:	c3                   	retq
>    2:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>    9:	00
>    a:	55                   	push   %rbp
>    b:	48 89 e5             	mov    %rsp,%rbp
>    e:	f4                   	hlt
>    f:	5d                   	pop    %rbp
>   10:	c3                   	retq
>   11:	66                   	data16
>   12:	0f                   	.byte 0xf
>   13:	1f                   	(bad)
>   14:	84 00                	test   %al,(%rax)
> [  880.960700] NMI backtrace for cpu 3
> [  880.960700] CPU: 3 PID: 32 Comm: migration/3 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8800a6cc0000 ti: ffff8800a6cc8000 task.ti: ffff8800a6cc8000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff8800a6ccfb78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed0067e09ee5 RCX: 1ffff10014d982d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff8800a6ccfbd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff88033f04f738 R14: 0000000000000001 R15: ffff88033f04f718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff8800a7200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000001490fe8 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff88033f04f728 0000000000000282
> [  880.960700]  ffff880000000000 00ff8800a6cc0000 ffff8800a6ccfbd8 dffffc0000000000
> [  880.960700]  ffff8800a7218440 ffff88033f04f778 ffff88033f04f718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 4
> [  880.960700] CPU: 4 PID: 41 Comm: migration/4 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8800cacb3000 ti: ffff8800cacc0000 task.ti: ffff8800cacc0000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff8800cacc7b78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed006e615ee5 RCX: 1ffff100195968d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff8800cacc7bd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff8803730af738 R14: 0000000000000001 R15: ffff8803730af718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff8800cf200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 000000000189efd8 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff8803730af728 0000000000000282
> [  880.960700]  ffff880000000000 00ff8800cacb3000 ffff8800cacc7bd8 dffffc0000000000
> [  880.960700]  ffff8800cf218440 ffff8803730af778 ffff8803730af718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 5
> [  880.960700] CPU: 5 PID: 50 Comm: migration/5 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff880128c6b000 ti: ffff880128c88000 task.ti: ffff880128c88000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff880128c8fb78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed008c0bbee5 RCX: 1ffff1002518d8d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff880128c8fbd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff8804605df738 R14: 0000000000000001 R15: ffff8804605df718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff880129000000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000002bf8ff0 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff8804605df728 0000000000000282
> [  880.960700]  ffff880100000000 00ff880128c6b000 ffff880128c8fbd8 dffffc0000000000
> [  880.960700]  ffff880129018440 ffff8804605df778 ffff8804605df718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 6
> [  880.960700] CPU: 6 PID: 59 Comm: migration/6 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff880152cb3000 ti: ffff880152cc0000 task.ti: ffff880152cc0000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff880152cc7b78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed0063d8cee5 RCX: 1ffff1002a5968d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff880152cc7bd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff88031ec67738 R14: 0000000000000001 R15: ffff88031ec67718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff880153200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000002b54fa0 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff88031ec67728 0000000000000282
> [  880.960700]  ffff880100000000 00ff880152cb3000 ffff880152cc7bd8 dffffc0000000000
> [  880.960700]  ffff880153218440 ffff88031ec67778 ffff88031ec67718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 7
> [  880.960700] CPU: 7 PID: 0 Comm: swapper/7 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8808dd0b0000 ti: ffff88000e2d0000 task.ti: ffff88000e2d0000
> [  880.960700] RIP: native_safe_halt (./arch/x86/include/asm/irqflags.h:50)
> [  880.960700] RSP: 0000:ffff88000e2d7d38  EFLAGS: 00000282
> [  880.960700] RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000000000
> [  880.960700] RDX: 1ffffffff4115884 RSI: 0000000000000001 RDI: ffffffffa08ac420
> [  880.960700] RBP: ffff88000e2d7d38 R08: 0000000000000000 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffa31716b4
> [  880.960700] R13: ffff88000e2d7fd8 R14: 0000000000000000 R15: ffff88000e2d7fd8
> [  880.960700] FS:  0000000000000000(0000) GS:ffff88017d200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000000000000 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffff88000e2d7d68 ffffffff93160774 dffffc0000000000 ffffffffa31716b4
> [  880.960700]  ffff88000e2d7fd8 0000000000000000 ffff88000e2d7d78 ffffffff931629ef
> [  880.960700]  ffff88000e2d7e68 ffffffff934018e0 0000000000000000 0000000000000000
> [  880.960700] Call Trace:
> [  880.960700] default_idle (./arch/x86/include/asm/paravirt.h:111 arch/x86/kernel/process.c:314)
> [  880.960700] arch_cpu_idle (arch/x86/kernel/process.c:306)
> [  880.960700] cpu_startup_entry (./arch/x86/include/asm/thread_info.h:162 include/linux/sched.h:2880 kernel/sched/idle.c:189 kernel/sched/idle.c:250 kernel/sched/idle.c:298)
> [  880.960700] ? arch_cpu_idle_prepare (??:?)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? clockevents_register_device (kernel/time/clockevents.c:481)
> [  880.960700] start_secondary (arch/x86/kernel/smpboot.c:219)
> [  880.960700] ? set_cpu_sibling_map (arch/x86/kernel/smpboot.c:219)
> [ 880.960700] Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84
> All code
> ========
>    0:	00 00                	add    %al,(%rax)
>    2:	00 00                	add    %al,(%rax)
>    4:	00 55 48             	add    %dl,0x48(%rbp)
>    7:	89 e5                	mov    %esp,%ebp
>    9:	fa                   	cli
>    a:	5d                   	pop    %rbp
>    b:	c3                   	retq
>    c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   13:	00 00
>   15:	55                   	push   %rbp
>   16:	48 89 e5             	mov    %rsp,%rbp
>   19:	fb                   	sti
>   1a:	5d                   	pop    %rbp
>   1b:	c3                   	retq
>   1c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   23:	00 00
>   25:	55                   	push   %rbp
>   26:	48 89 e5             	mov    %rsp,%rbp
>   29:	fb                   	sti
>   2a:	f4                   	hlt
>   2b:*	5d                   	pop    %rbp		<-- trapping instruction
>   2c:	c3                   	retq
>   2d:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>   34:	00
>   35:	55                   	push   %rbp
>   36:	48 89 e5             	mov    %rsp,%rbp
>   39:	f4                   	hlt
>   3a:	5d                   	pop    %rbp
>   3b:	c3                   	retq
>   3c:	66                   	data16
>   3d:	0f                   	.byte 0xf
>   3e:	1f                   	(bad)
>   3f:	84 00                	test   %al,(%rax)
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	5d                   	pop    %rbp
>    1:	c3                   	retq
>    2:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>    9:	00
>    a:	55                   	push   %rbp
>    b:	48 89 e5             	mov    %rsp,%rbp
>    e:	f4                   	hlt
>    f:	5d                   	pop    %rbp
>   10:	c3                   	retq
>   11:	66                   	data16
>   12:	0f                   	.byte 0xf
>   13:	1f                   	(bad)
>   14:	84 00                	test   %al,(%rax)
> [  880.960700] NMI backtrace for cpu 8
> [  880.960700] CPU: 8 PID: 77 Comm: migration/8 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8801a6cc0000 ti: ffff8801a6cc8000 task.ti: ffff8801a6cc8000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff8801a6ccfb78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed003abaaee5 RCX: 1ffff10034d982d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff8801a6ccfbd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff8801d5d57738 R14: 0000000000000001 R15: ffff8801d5d57718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff8801a7200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000000e69fc8 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff8801d5d57728 0000000000000282
> [  880.960700]  ffff880100000000 00ff8801a6cc0000 ffff8801a6ccfbd8 dffffc0000000000
> [  880.960700]  ffff8801a7218440 ffff8801d5d57778 ffff8801d5d57718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 9
> [  880.960700] CPU: 9 PID: 86 Comm: migration/9 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8801d0c88000 ti: ffff8801d0c90000 task.ti: ffff8801d0c90000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff8801d0c97b78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed007245bee5 RCX: 1ffff1003a1912d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff8801d0c97bd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff8803922df738 R14: 0000000000000001 R15: ffff8803922df718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff8801d1000000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 00000000029a8fb0 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff8803922df728 0000000000000282
> [  880.960700]  ffff880100000000 00ff8801d0c88000 ffff8801d0c97bd8 dffffc0000000000
> [  880.960700]  ffff8801d1018440 ffff8803922df778 ffff8803922df718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 10
> [  880.960700] CPU: 10 PID: 0 Comm: swapper/10 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff880128c68000 ti: ffff88000e6c0000 task.ti: ffff88000e6c0000
> [  880.960700] RIP: native_safe_halt (./arch/x86/include/asm/irqflags.h:50)
> [  880.960700] RSP: 0018:ffff88000e6c7d38  EFLAGS: 00000282
> [  880.960700] RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000000000
> [  880.960700] RDX: 1ffffffff4115884 RSI: 0000000000000001 RDI: ffffffffa08ac420
> [  880.960700] RBP: ffff88000e6c7d38 R08: 0000000000000000 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffa31716b4
> [  880.960700] R13: ffff88000e6c7fd8 R14: 0000000000000000 R15: ffff88000e6c7fd8
> [  880.960700] FS:  0000000000000000(0000) GS:ffff8801fb200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000000636668 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffff88000e6c7d68 ffffffff93160774 dffffc0000000000 ffffffffa31716b4
> [  880.960700]  ffff88000e6c7fd8 0000000000000000 ffff88000e6c7d78 ffffffff931629ef
> [  880.960700]  ffff88000e6c7e68 ffffffff934018e0 0000000000000000 0000000000000000
> [  880.960700] Call Trace:
> [  880.960700] default_idle (./arch/x86/include/asm/paravirt.h:111 arch/x86/kernel/process.c:314)
> [  880.960700] arch_cpu_idle (arch/x86/kernel/process.c:306)
> [  880.960700] cpu_startup_entry (./arch/x86/include/asm/thread_info.h:162 include/linux/sched.h:2880 kernel/sched/idle.c:189 kernel/sched/idle.c:250 kernel/sched/idle.c:298)
> [  880.960700] ? arch_cpu_idle_prepare (??:?)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? clockevents_register_device (kernel/time/clockevents.c:481)
> [  880.960700] start_secondary (arch/x86/kernel/smpboot.c:219)
> [  880.960700] ? set_cpu_sibling_map (arch/x86/kernel/smpboot.c:219)
> [ 880.960700] Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84
> All code
> ========
>    0:	00 00                	add    %al,(%rax)
>    2:	00 00                	add    %al,(%rax)
>    4:	00 55 48             	add    %dl,0x48(%rbp)
>    7:	89 e5                	mov    %esp,%ebp
>    9:	fa                   	cli
>    a:	5d                   	pop    %rbp
>    b:	c3                   	retq
>    c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   13:	00 00
>   15:	55                   	push   %rbp
>   16:	48 89 e5             	mov    %rsp,%rbp
>   19:	fb                   	sti
>   1a:	5d                   	pop    %rbp
>   1b:	c3                   	retq
>   1c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   23:	00 00
>   25:	55                   	push   %rbp
>   26:	48 89 e5             	mov    %rsp,%rbp
>   29:	fb                   	sti
>   2a:	f4                   	hlt
>   2b:*	5d                   	pop    %rbp		<-- trapping instruction
>   2c:	c3                   	retq
>   2d:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>   34:	00
>   35:	55                   	push   %rbp
>   36:	48 89 e5             	mov    %rsp,%rbp
>   39:	f4                   	hlt
>   3a:	5d                   	pop    %rbp
>   3b:	c3                   	retq
>   3c:	66                   	data16
>   3d:	0f                   	.byte 0xf
>   3e:	1f                   	(bad)
>   3f:	84 00                	test   %al,(%rax)
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	5d                   	pop    %rbp
>    1:	c3                   	retq
>    2:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>    9:	00
>    a:	55                   	push   %rbp
>    b:	48 89 e5             	mov    %rsp,%rbp
>    e:	f4                   	hlt
>    f:	5d                   	pop    %rbp
>   10:	c3                   	retq
>   11:	66                   	data16
>   12:	0f                   	.byte 0xf
>   13:	1f                   	(bad)
>   14:	84 00                	test   %al,(%rax)
> [  880.960700] NMI backtrace for cpu 11
> [  880.960700] CPU: 11 PID: 0 Comm: swapper/11 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8801a6ca8000 ti: ffff88000e6c8000 task.ti: ffff88000e6c8000
> [  880.960700] RIP: native_safe_halt (./arch/x86/include/asm/irqflags.h:50)
> [  880.960700] RSP: 0018:ffff88000e6cfd38  EFLAGS: 00000282
> [  880.960700] RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000000000
> [  880.960700] RDX: 1ffffffff4115884 RSI: 0000000000000001 RDI: ffffffffa08ac420
> [  880.960700] RBP: ffff88000e6cfd38 R08: 0000000000000000 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffa31716b4
> [  880.960700] R13: ffff88000e6cffd8 R14: 0000000000000000 R15: ffff88000e6cffd8
> [  880.960700] FS:  0000000000000000(0000) GS:ffff880225200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 00000000030db000 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffff88000e6cfd68 ffffffff93160774 dffffc0000000000 ffffffffa31716b4
> [  880.960700]  ffff88000e6cffd8 0000000000000000 ffff88000e6cfd78 ffffffff931629ef
> [  880.960700]  ffff88000e6cfe68 ffffffff934018e0 ffff88000e6cfde8 ffffffff9dbf7ec5
> [  880.960700] Call Trace:
> [  880.960700] default_idle (./arch/x86/include/asm/paravirt.h:111 arch/x86/kernel/process.c:314)
> [  880.960700] arch_cpu_idle (arch/x86/kernel/process.c:306)
> [  880.960700] cpu_startup_entry (./arch/x86/include/asm/thread_info.h:162 include/linux/sched.h:2880 kernel/sched/idle.c:189 kernel/sched/idle.c:250 kernel/sched/idle.c:298)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? arch_cpu_idle_prepare (??:?)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? clockevents_register_device (kernel/time/clockevents.c:481)
> [  880.960700] start_secondary (arch/x86/kernel/smpboot.c:219)
> [  880.960700] ? set_cpu_sibling_map (arch/x86/kernel/smpboot.c:219)
> [ 880.960700] Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84
> All code
> ========
>    0:	00 00                	add    %al,(%rax)
>    2:	00 00                	add    %al,(%rax)
>    4:	00 55 48             	add    %dl,0x48(%rbp)
>    7:	89 e5                	mov    %esp,%ebp
>    9:	fa                   	cli
>    a:	5d                   	pop    %rbp
>    b:	c3                   	retq
>    c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   13:	00 00
>   15:	55                   	push   %rbp
>   16:	48 89 e5             	mov    %rsp,%rbp
>   19:	fb                   	sti
>   1a:	5d                   	pop    %rbp
>   1b:	c3                   	retq
>   1c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   23:	00 00
>   25:	55                   	push   %rbp
>   26:	48 89 e5             	mov    %rsp,%rbp
>   29:	fb                   	sti
>   2a:	f4                   	hlt
>   2b:*	5d                   	pop    %rbp		<-- trapping instruction
>   2c:	c3                   	retq
>   2d:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>   34:	00
>   35:	55                   	push   %rbp
>   36:	48 89 e5             	mov    %rsp,%rbp
>   39:	f4                   	hlt
>   3a:	5d                   	pop    %rbp
>   3b:	c3                   	retq
>   3c:	66                   	data16
>   3d:	0f                   	.byte 0xf
>   3e:	1f                   	(bad)
>   3f:	84 00                	test   %al,(%rax)
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	5d                   	pop    %rbp
>    1:	c3                   	retq
>    2:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>    9:	00
>    a:	55                   	push   %rbp
>    b:	48 89 e5             	mov    %rsp,%rbp
>    e:	f4                   	hlt
>    f:	5d                   	pop    %rbp
>   10:	c3                   	retq
>   11:	66                   	data16
>   12:	0f                   	.byte 0xf
>   13:	1f                   	(bad)
>   14:	84 00                	test   %al,(%rax)
> [  880.960700] NMI backtrace for cpu 12
> [  880.960700] CPU: 12 PID: 113 Comm: migration/12 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff88024ecd0000 ti: ffff88024ecd8000 task.ti: ffff88024ecd8000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff88024ecdfb78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed0073a32ee5 RCX: 1ffff10049d9a2d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff88024ecdfbd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff88039d197738 R14: 0000000000000001 R15: ffff88039d197718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff88024f200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000002648fe0 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff88039d197728 0000000000000282
> [  880.960700]  ffff880200000000 00ff88024ecd0000 ffff88024ecdfbd8 dffffc0000000000
> [  880.960700]  ffff88024f218440 ffff88039d197778 ffff88039d197718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 13
> [  880.960700] CPU: 13 PID: 0 Comm: swapper/13 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8802f6cc0000 ti: ffff88000e6d8000 task.ti: ffff88000e6d8000
> [  880.960700] RIP: native_safe_halt (./arch/x86/include/asm/irqflags.h:50)
> [  880.960700] RSP: 0018:ffff88000e6dfd38  EFLAGS: 00000282
> [  880.960700] RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000000000
> [  880.960700] RDX: 1ffffffff4115884 RSI: 0000000000000001 RDI: ffffffffa08ac420
> [  880.960700] RBP: ffff88000e6dfd38 R08: 0000000000000000 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffa31716b4
> [  880.960700] R13: ffff88000e6dffd8 R14: 0000000000000000 R15: ffff88000e6dffd8
> [  880.960700] FS:  0000000000000000(0000) GS:ffff880279000000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 000000000063a69c CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffff88000e6dfd68 ffffffff93160774 dffffc0000000000 ffffffffa31716b4
> [  880.960700]  ffff88000e6dffd8 0000000000000000 ffff88000e6dfd78 ffffffff931629ef
> [  880.960700]  ffff88000e6dfe68 ffffffff934018e0 ffff88000e6dfde8 ffffffff9dbf7ec5
> [  880.960700] Call Trace:
> [  880.960700] default_idle (./arch/x86/include/asm/paravirt.h:111 arch/x86/kernel/process.c:314)
> [  880.960700] arch_cpu_idle (arch/x86/kernel/process.c:306)
> [  880.960700] cpu_startup_entry (./arch/x86/include/asm/thread_info.h:162 include/linux/sched.h:2880 kernel/sched/idle.c:189 kernel/sched/idle.c:250 kernel/sched/idle.c:298)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? arch_cpu_idle_prepare (??:?)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? clockevents_register_device (kernel/time/clockevents.c:481)
> [  880.960700] start_secondary (arch/x86/kernel/smpboot.c:219)
> [  880.960700] ? set_cpu_sibling_map (arch/x86/kernel/smpboot.c:219)
> [ 880.960700] Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84
> All code
> ========
>    0:	00 00                	add    %al,(%rax)
>    2:	00 00                	add    %al,(%rax)
>    4:	00 55 48             	add    %dl,0x48(%rbp)
>    7:	89 e5                	mov    %esp,%ebp
>    9:	fa                   	cli
>    a:	5d                   	pop    %rbp
>    b:	c3                   	retq
>    c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   13:	00 00
>   15:	55                   	push   %rbp
>   16:	48 89 e5             	mov    %rsp,%rbp
>   19:	fb                   	sti
>   1a:	5d                   	pop    %rbp
>   1b:	c3                   	retq
>   1c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   23:	00 00
>   25:	55                   	push   %rbp
>   26:	48 89 e5             	mov    %rsp,%rbp
>   29:	fb                   	sti
>   2a:	f4                   	hlt
>   2b:*	5d                   	pop    %rbp		<-- trapping instruction
>   2c:	c3                   	retq
>   2d:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>   34:	00
>   35:	55                   	push   %rbp
>   36:	48 89 e5             	mov    %rsp,%rbp
>   39:	f4                   	hlt
>   3a:	5d                   	pop    %rbp
>   3b:	c3                   	retq
>   3c:	66                   	data16
>   3d:	0f                   	.byte 0xf
>   3e:	1f                   	(bad)
>   3f:	84 00                	test   %al,(%rax)
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	5d                   	pop    %rbp
>    1:	c3                   	retq
>    2:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>    9:	00
>    a:	55                   	push   %rbp
>    b:	48 89 e5             	mov    %rsp,%rbp
>    e:	f4                   	hlt
>    f:	5d                   	pop    %rbp
>   10:	c3                   	retq
>   11:	66                   	data16
>   12:	0f                   	.byte 0xf
>   13:	1f                   	(bad)
>   14:	84 00                	test   %al,(%rax)
> [  880.960700] NMI backtrace for cpu 14
> [  880.960700] CPU: 14 PID: 131 Comm: migration/14 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8802a2cdb000 ti: ffff8802a2ce8000 task.ti: ffff8802a2ce8000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff8802a2cefb78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed0059614ee5 RCX: 1ffff1005459b8d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff8802a2cefbd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff8802cb0a7738 R14: 0000000000000001 R15: ffff8802cb0a7718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff8802a3200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000002cc8ff8 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff8802cb0a7728 0000000000000282
> [  880.960700]  ffff880200000000 00ff8802a2cdb000 ffff8802a2cefbd8 dffffc0000000000
> [  880.960700]  ffff8802a3218440 ffff8802cb0a7778 ffff8802cb0a7718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 15
> [  880.960700] CPU: 15 PID: 140 Comm: migration/15 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8802ccca3000 ti: ffff8802cccd0000 task.ti: ffff8802cccd0000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff8802cccd7b78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed0023834ee5 RCX: 1ffff100599948d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff8802cccd7bd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff88011c1a7738 R14: 0000000000000001 R15: ffff88011c1a7718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff8802cd200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000001ad0a08 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff88011c1a7728 0000000000000282
> [  880.960700]  ffff880200000000 00ff8802ccca3000 ffff8802cccd7bd8 dffffc0000000000
> [  880.960700]  ffff8802cd218440 ffff88011c1a7778 ffff88011c1a7718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 16
> [  880.960700] CPU: 16 PID: 149 Comm: migration/16 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8802f6ce8000 ti: ffff8802f6cf0000 task.ti: ffff8802f6cf0000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff8802f6cf7b78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed00149d5ee5 RCX: 1ffff1005ed9d2d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff8802f6cf7bd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff8800a4eaf738 R14: 0000000000000001 R15: ffff8800a4eaf718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff8802f7200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000001f6afe8 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff8800a4eaf728 0000000000000282
> [  880.960700]  ffff880200000000 00ff8802f6ce8000 ffff8802f6cf7bd8 dffffc0000000000
> [  880.960700]  ffff8802f7218440 ffff8800a4eaf778 ffff8800a4eaf718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 17
> [  880.960700] CPU: 17 PID: 158 Comm: migration/17 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff880320c7b000 ti: ffff880320c88000 task.ti: ffff880320c88000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff880320c8fb78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed000b451ee5 RCX: 1ffff1006418f8d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff880320c8fbd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff88005a28f738 R14: 0000000000000001 R15: ffff88005a28f718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff880321000000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 000000000161bff8 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff88005a28f728 0000000000000282
> [  880.960700]  ffff880300000000 00ff880320c7b000 ffff880320c8fbd8 dffffc0000000000
> [  880.960700]  ffff880321018440 ffff88005a28f778 ffff88005a28f718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 18
> [  880.960700] CPU: 18 PID: 0 Comm: swapper/18 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8806ad0b0000 ti: ffff88000eac0000 task.ti: ffff88000eac0000
> [  880.960700] RIP: native_safe_halt (./arch/x86/include/asm/irqflags.h:50)
> [  880.960700] RSP: 0018:ffff88000eac7d38  EFLAGS: 00000282
> [  880.960700] RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000000000
> [  880.960700] RDX: 1ffffffff4115884 RSI: 0000000000000001 RDI: ffffffffa08ac420
> [  880.960700] RBP: ffff88000eac7d38 R08: 0000000000000000 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffa31716b4
> [  880.960700] R13: ffff88000eac7fd8 R14: 0000000000000000 R15: ffff88000eac7fd8
> [  880.960700] FS:  0000000000000000(0000) GS:ffff88034b200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000001692ac0 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffff88000eac7d68 ffffffff93160774 dffffc0000000000 ffffffffa31716b4
> [  880.960700]  ffff88000eac7fd8 0000000000000000 ffff88000eac7d78 ffffffff931629ef
> [  880.960700]  ffff88000eac7e68 ffffffff934018e0 ffff88000eac7de8 ffffffff9dbf7ec5
> [  880.960700] Call Trace:
> [  880.960700] default_idle (./arch/x86/include/asm/paravirt.h:111 arch/x86/kernel/process.c:314)
> [  880.960700] arch_cpu_idle (arch/x86/kernel/process.c:306)
> [  880.960700] cpu_startup_entry (./arch/x86/include/asm/thread_info.h:162 include/linux/sched.h:2880 kernel/sched/idle.c:189 kernel/sched/idle.c:250 kernel/sched/idle.c:298)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? arch_cpu_idle_prepare (??:?)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? clockevents_register_device (kernel/time/clockevents.c:481)
> [  880.960700] start_secondary (arch/x86/kernel/smpboot.c:219)
> [  880.960700] ? set_cpu_sibling_map (arch/x86/kernel/smpboot.c:219)
> [ 880.960700] Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84
> All code
> ========
>    0:	00 00                	add    %al,(%rax)
>    2:	00 00                	add    %al,(%rax)
>    4:	00 55 48             	add    %dl,0x48(%rbp)
>    7:	89 e5                	mov    %esp,%ebp
>    9:	fa                   	cli
>    a:	5d                   	pop    %rbp
>    b:	c3                   	retq
>    c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   13:	00 00
>   15:	55                   	push   %rbp
>   16:	48 89 e5             	mov    %rsp,%rbp
>   19:	fb                   	sti
>   1a:	5d                   	pop    %rbp
>   1b:	c3                   	retq
>   1c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   23:	00 00
>   25:	55                   	push   %rbp
>   26:	48 89 e5             	mov    %rsp,%rbp
>   29:	fb                   	sti
>   2a:	f4                   	hlt
>   2b:*	5d                   	pop    %rbp		<-- trapping instruction
>   2c:	c3                   	retq
>   2d:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>   34:	00
>   35:	55                   	push   %rbp
>   36:	48 89 e5             	mov    %rsp,%rbp
>   39:	f4                   	hlt
>   3a:	5d                   	pop    %rbp
>   3b:	c3                   	retq
>   3c:	66                   	data16
>   3d:	0f                   	.byte 0xf
>   3e:	1f                   	(bad)
>   3f:	84 00                	test   %al,(%rax)
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	5d                   	pop    %rbp
>    1:	c3                   	retq
>    2:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>    9:	00
>    a:	55                   	push   %rbp
>    b:	48 89 e5             	mov    %rsp,%rbp
>    e:	f4                   	hlt
>    f:	5d                   	pop    %rbp
>   10:	c3                   	retq
>   11:	66                   	data16
>   12:	0f                   	.byte 0xf
>   13:	1f                   	(bad)
>   14:	84 00                	test   %al,(%rax)
> [  880.960700] NMI backtrace for cpu 19
> [  880.960700] CPU: 19 PID: 0 Comm: swapper/19 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8807ed0c8000 ti: ffff88000eac8000 task.ti: ffff88000eac8000
> [  880.960700] RIP: native_safe_halt (./arch/x86/include/asm/irqflags.h:50)
> [  880.960700] RSP: 0018:ffff88000eacfd38  EFLAGS: 00000282
> [  880.960700] RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000000000
> [  880.960700] RDX: 1ffffffff4115884 RSI: 0000000000000001 RDI: ffffffffa08ac420
> [  880.960700] RBP: ffff88000eacfd38 R08: 0000000000000000 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffa31716b4
> [  880.960700] R13: ffff88000eacffd8 R14: 0000000000000000 R15: ffff88000eacffd8
> [  880.960700] FS:  0000000000000000(0000) GS:ffff880375200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 00007ffe1ae26d00 CR3: 000000000660a000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffff88000eacfd68 ffffffff93160774 dffffc0000000000 ffffffffa31716b4
> [  880.960700]  ffff88000eacffd8 0000000000000000 ffff88000eacfd78 ffffffff931629ef
> [  880.960700]  ffff88000eacfe68 ffffffff934018e0 ffff88000eacfde8 ffffffff9dbf7ec5
> [  880.960700] Call Trace:
> [  880.960700] default_idle (./arch/x86/include/asm/paravirt.h:111 arch/x86/kernel/process.c:314)
> [  880.960700] arch_cpu_idle (arch/x86/kernel/process.c:306)
> [  880.960700] cpu_startup_entry (./arch/x86/include/asm/thread_info.h:162 include/linux/sched.h:2880 kernel/sched/idle.c:189 kernel/sched/idle.c:250 kernel/sched/idle.c:298)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? arch_cpu_idle_prepare (??:?)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? clockevents_register_device (kernel/time/clockevents.c:481)
> [  880.960700] start_secondary (arch/x86/kernel/smpboot.c:219)
> [  880.960700] ? set_cpu_sibling_map (arch/x86/kernel/smpboot.c:219)
> [ 880.960700] Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84
> All code
> ========
>    0:	00 00                	add    %al,(%rax)
>    2:	00 00                	add    %al,(%rax)
>    4:	00 55 48             	add    %dl,0x48(%rbp)
>    7:	89 e5                	mov    %esp,%ebp
>    9:	fa                   	cli
>    a:	5d                   	pop    %rbp
>    b:	c3                   	retq
>    c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   13:	00 00
>   15:	55                   	push   %rbp
>   16:	48 89 e5             	mov    %rsp,%rbp
>   19:	fb                   	sti
>   1a:	5d                   	pop    %rbp
>   1b:	c3                   	retq
>   1c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   23:	00 00
>   25:	55                   	push   %rbp
>   26:	48 89 e5             	mov    %rsp,%rbp
>   29:	fb                   	sti
>   2a:	f4                   	hlt
>   2b:*	5d                   	pop    %rbp		<-- trapping instruction
>   2c:	c3                   	retq
>   2d:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>   34:	00
>   35:	55                   	push   %rbp
>   36:	48 89 e5             	mov    %rsp,%rbp
>   39:	f4                   	hlt
>   3a:	5d                   	pop    %rbp
>   3b:	c3                   	retq
>   3c:	66                   	data16
>   3d:	0f                   	.byte 0xf
>   3e:	1f                   	(bad)
>   3f:	84 00                	test   %al,(%rax)
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	5d                   	pop    %rbp
>    1:	c3                   	retq
>    2:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>    9:	00
>    a:	55                   	push   %rbp
>    b:	48 89 e5             	mov    %rsp,%rbp
>    e:	f4                   	hlt
>    f:	5d                   	pop    %rbp
>   10:	c3                   	retq
>   11:	66                   	data16
>   12:	0f                   	.byte 0xf
>   13:	1f                   	(bad)
>   14:	84 00                	test   %al,(%rax)
> [  880.960700] NMI backtrace for cpu 20
> [  880.960700] CPU: 20 PID: 185 Comm: migration/20 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff88039ece0000 ti: ffff88039ece8000 task.ti: ffff88039ece8000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff88039ecefb78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed008ddccee5 RCX: 1ffff10073d9c2d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff88039ecefbd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff88046ee67738 R14: 0000000000000001 R15: ffff88046ee67718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff88039f200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 00000000029aeff8 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff88046ee67728 0000000000000282
> [  880.960700]  ffff880300000000 00ff88039ece0000 ffff88039ecefbd8 dffffc0000000000
> [  880.960700]  ffff88039f218440 ffff88046ee67778 ffff88046ee67718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 21
> [  880.960700] CPU: 21 PID: 194 Comm: migration/21 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8803c8ca8000 ti: ffff8803c8cb0000 task.ti: ffff8803c8cb0000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff8803c8cb7b78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed00149caee5 RCX: 1ffff100791952d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff8803c8cb7bd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff8800a4e57738 R14: 0000000000000001 R15: ffff8800a4e57718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff8803c9000000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000002914fb0 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff8800a4e57728 0000000000000282
> [  880.960700]  ffff880300000000 00ff8803c8ca8000 ffff8803c8cb7bd8 dffffc0000000000
> [  880.960700]  ffff8803c9018440 ffff8800a4e57778 ffff8800a4e57718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 22
> [  880.960700] CPU: 22 PID: 203 Comm: migration/22 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8803f2cdb000 ti: ffff8803f2ce8000 task.ti: ffff8803f2ce8000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff8803f2cefb78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed008dde3ee5 RCX: 1ffff1007e59b8d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff8803f2cefbd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff88046ef1f738 R14: 0000000000000001 R15: ffff88046ef1f718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff8803f3200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000002e38b80 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff88046ef1f728 0000000000000282
> [  880.960700]  ffff880300000000 00ff8803f2cdb000 ffff8803f2cefbd8 dffffc0000000000
> [  880.960700]  ffff8803f3218440 ffff88046ef1f778 ffff88046ef1f718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 23
> [  880.960700] CPU: 23 PID: 212 Comm: migration/23 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff88041cc7b000 ti: ffff88041cce0000 task.ti: ffff88041cce0000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff88041cce7b78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed006926eee5 RCX: 1ffff1008398f8d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff88041cce7bd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff880349377738 R14: 0000000000000001 R15: ffff880349377718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff88041d200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 00007f9c055599d0 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff880349377728 0000000000000282
> [  880.960700]  ffff880400000000 00ff88041cc7b000 ffff88041cce7bd8 dffffc0000000000
> [  880.960700]  ffff88041d218440 ffff880349377778 ffff880349377718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 24
> [  880.960700] CPU: 24 PID: 0 Comm: swapper/24 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8801d0c68000 ti: ffff88000eed0000 task.ti: ffff88000eed0000
> [  880.960700] RIP: native_safe_halt (./arch/x86/include/asm/irqflags.h:50)
> [  880.960700] RSP: 0018:ffff88000eed7d38  EFLAGS: 00000282
> [  880.960700] RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000000000
> [  880.960700] RDX: 1ffffffff4115884 RSI: 0000000000000001 RDI: ffffffffa08ac420
> [  880.960700] RBP: ffff88000eed7d38 R08: 0000000000000000 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffa31716b4
> [  880.960700] R13: ffff88000eed7fd8 R14: 0000000000000000 R15: ffff88000eed7fd8
> [  880.960700] FS:  0000000000000000(0000) GS:ffff880447200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 00000000029e4220 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffff88000eed7d68 ffffffff93160774 dffffc0000000000 ffffffffa31716b4
> [  880.960700]  ffff88000eed7fd8 0000000000000000 ffff88000eed7d78 ffffffff931629ef
> [  880.960700]  ffff88000eed7e68 ffffffff934018e0 ffff88000eed7de8 ffffffff9dbf7ec5
> [  880.960700] Call Trace:
> [  880.960700] default_idle (./arch/x86/include/asm/paravirt.h:111 arch/x86/kernel/process.c:314)
> [  880.960700] arch_cpu_idle (arch/x86/kernel/process.c:306)
> [  880.960700] cpu_startup_entry (./arch/x86/include/asm/thread_info.h:162 include/linux/sched.h:2880 kernel/sched/idle.c:189 kernel/sched/idle.c:250 kernel/sched/idle.c:298)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? arch_cpu_idle_prepare (??:?)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? clockevents_register_device (kernel/time/clockevents.c:481)
> [  880.960700] start_secondary (arch/x86/kernel/smpboot.c:219)
> [  880.960700] ? set_cpu_sibling_map (arch/x86/kernel/smpboot.c:219)
> [ 880.960700] Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84
> All code
> ========
>    0:	00 00                	add    %al,(%rax)
>    2:	00 00                	add    %al,(%rax)
>    4:	00 55 48             	add    %dl,0x48(%rbp)
>    7:	89 e5                	mov    %esp,%ebp
>    9:	fa                   	cli
>    a:	5d                   	pop    %rbp
>    b:	c3                   	retq
>    c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   13:	00 00
>   15:	55                   	push   %rbp
>   16:	48 89 e5             	mov    %rsp,%rbp
>   19:	fb                   	sti
>   1a:	5d                   	pop    %rbp
>   1b:	c3                   	retq
>   1c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   23:	00 00
>   25:	55                   	push   %rbp
>   26:	48 89 e5             	mov    %rsp,%rbp
>   29:	fb                   	sti
>   2a:	f4                   	hlt
>   2b:*	5d                   	pop    %rbp		<-- trapping instruction
>   2c:	c3                   	retq
>   2d:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>   34:	00
>   35:	55                   	push   %rbp
>   36:	48 89 e5             	mov    %rsp,%rbp
>   39:	f4                   	hlt
>   3a:	5d                   	pop    %rbp
>   3b:	c3                   	retq
>   3c:	66                   	data16
>   3d:	0f                   	.byte 0xf
>   3e:	1f                   	(bad)
>   3f:	84 00                	test   %al,(%rax)
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	5d                   	pop    %rbp
>    1:	c3                   	retq
>    2:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>    9:	00
>    a:	55                   	push   %rbp
>    b:	48 89 e5             	mov    %rsp,%rbp
>    e:	f4                   	hlt
>    f:	5d                   	pop    %rbp
>   10:	c3                   	retq
>   11:	66                   	data16
>   12:	0f                   	.byte 0xf
>   13:	1f                   	(bad)
>   14:	84 00                	test   %al,(%rax)
> [  880.960700] NMI backtrace for cpu 25
> [  880.960700] CPU: 25 PID: 12438 Comm: trinity-c68 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8802cb318000 ti: ffff8802cb3a8000 task.ti: ffff8802cb3a8000
> [  880.960700] RIP: rwsem_down_write_failed (./arch/x86/include/asm/processor.h:658 ./arch/x86/include/asm/processor.h:663 kernel/locking/rwsem-xadd.c:413 kernel/locking/rwsem-xadd.c:442)
> [  880.960700] RSP: 0018:ffff8802cb3afc08  EFLAGS: 00000286
> [  880.960700] RAX: ffffffff00000001 RBX: ffffffffa18e12a8 RCX: ffff8802cb318000
> [  880.960700] RDX: fffffffe00000001 RSI: fffffffeffffffff RDI: 0000000100000000
> [  880.960700] RBP: ffff8802cb3afd98 R08: 0000000000000000 R09: ffffffff00000001
> [  880.960700] R10: 0000000000000001 R11: 0000000000000001 R12: ffff8803f10c3000
> [  880.960700] R13: ffffffffa18e12a0 R14: ffff8802cb3afd68 R15: ffffffffa18e1250
> [  880.960700] FS:  00007f9c05559700(0000) GS:ffff880471000000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [  880.960700] CR2: 00007f9c0549b614 CR3: 00000002cb385000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffff9dbf3ced ffff8802cb318d00 0000000000000000 ffff8802cb318000
> [  880.960700]  00000000000004ff ffffffffa3ebf6b0 1ffff10059675f89 1ffff10059675f8d
> [  880.960700]  0000000041b58ab3 ffff8802cb3a8010 1ffff10059675002 ffff8802cb3a8000
> [  880.960700] Call Trace:
> [  880.960700] ? rwsem_down_write_failed (include/linux/rcupdate.h:912 kernel/locking/rwsem-xadd.c:306 kernel/locking/rwsem-xadd.c:381 kernel/locking/rwsem-xadd.c:442)
> [  880.960700] ? rwsem_down_read_failed (kernel/locking/rwsem-xadd.c:433)
> [  880.960700] ? trace_hardirqs_off (kernel/locking/lockdep.c:2647)
> [  880.960700] ? __acct_update_integrals (kernel/tsacct.c:125)
> [  880.960700] ? taskstats_exit (kernel/tsacct.c:125)
> [  880.960700] call_rwsem_down_write_failed (arch/x86/lib/rwsem.S:104)
> [  880.960700] ? down_write (kernel/locking/rwsem.h:4 kernel/locking/rwsem.c:52)
> [  880.960700] ? ipcget (ipc/util.c:349 ipc/util.c:646)
> [  880.960700] ipcget (ipc/util.c:349 ipc/util.c:646)
> [  880.960700] ? trace_hardirqs_on (kernel/locking/lockdep.c:2609)
> [  880.960700] ? syscall_trace_enter_phase1 (include/linux/context_tracking.h:27 arch/x86/kernel/ptrace.c:1486)
> [  880.960700] SyS_semget (ipc/sem.c:591 ipc/sem.c:572)
> [  880.960700] ? sem_exit_ns (ipc/sem.c:572)
> [  880.960700] ? trace_hardirqs_on_thunk (arch/x86/lib/thunk_64.S:42)
> [  880.960700] tracesys_phase2 (arch/x86/kernel/entry_64.S:347)
> [ 880.960700] Code: 8d 0c 0a 48 89 d0 f0 49 0f b1 0f 48 39 c2 0f 84 2b 04 00 00 48 89 c2 48 8d 04 3a 48 85 f0 74 df 4d 85 e4 0f 84 50 04 00 00 f3 90 <e9> 57 ff ff ff e8 02 62 87 f5 84 c0 0f 85 f5 fd ff ff 48 c7 c2
> All code
> ========
>    0:	8d 0c 0a             	lea    (%rdx,%rcx,1),%ecx
>    3:	48 89 d0             	mov    %rdx,%rax
>    6:	f0 49 0f b1 0f       	lock cmpxchg %rcx,(%r15)
>    b:	48 39 c2             	cmp    %rax,%rdx
>    e:	0f 84 2b 04 00 00    	je     0x43f
>   14:	48 89 c2             	mov    %rax,%rdx
>   17:	48 8d 04 3a          	lea    (%rdx,%rdi,1),%rax
>   1b:	48 85 f0             	test   %rsi,%rax
>   1e:	74 df                	je     0xffffffffffffffff
>   20:	4d 85 e4             	test   %r12,%r12
>   23:	0f 84 50 04 00 00    	je     0x479
>   29:	f3 90                	pause
>   2b:*	e9 57 ff ff ff       	jmpq   0xffffffffffffff87		<-- trapping instruction
>   30:	e8 02 62 87 f5       	callq  0xfffffffff5876237
>   35:	84 c0                	test   %al,%al
>   37:	0f 85 f5 fd ff ff    	jne    0xfffffffffffffe32
>   3d:	48                   	rex.W
>   3e:	c7                   	.byte 0xc7
>   3f:	c2                   	.byte 0xc2
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	e9 57 ff ff ff       	jmpq   0xffffffffffffff5c
>    5:	e8 02 62 87 f5       	callq  0xfffffffff587620c
>    a:	84 c0                	test   %al,%al
>    c:	0f 85 f5 fd ff ff    	jne    0xfffffffffffffe07
>   12:	48                   	rex.W
>   13:	c7                   	.byte 0xc7
>   14:	c2                   	.byte 0xc2
> 	...
> [  880.960700] NMI backtrace for cpu 26
> [  880.960700] CPU: 26 PID: 0 Comm: swapper/26 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8803c8c78000 ti: ffff88000eee0000 task.ti: ffff88000eee0000
> [  880.960700] RIP: native_safe_halt (./arch/x86/include/asm/irqflags.h:50)
> [  880.960700] RSP: 0018:ffff88000eee7d38  EFLAGS: 00000282
> [  880.960700] RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000000000
> [  880.960700] RDX: 1ffffffff4115884 RSI: 0000000000000001 RDI: ffffffffa08ac420
> [  880.960700] RBP: ffff88000eee7d38 R08: 0000000000000000 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffa31716b4
> [  880.960700] R13: ffff88000eee7fd8 R14: 0000000000000000 R15: ffff88000eee7fd8
> [  880.960700] FS:  0000000000000000(0000) GS:ffff88049b200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 00007f0f2bc1d5a8 CR3: 000000000678f000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffff88000eee7d68 ffffffff93160774 dffffc0000000000 ffffffffa31716b4
> [  880.960700]  ffff88000eee7fd8 0000000000000000 ffff88000eee7d78 ffffffff931629ef
> [  880.960700]  ffff88000eee7e68 ffffffff934018e0 ffff88000eee7de8 ffffffff9dbf7ec5
> [  880.960700] Call Trace:
> [  880.960700] default_idle (./arch/x86/include/asm/paravirt.h:111 arch/x86/kernel/process.c:314)
> [  880.960700] arch_cpu_idle (arch/x86/kernel/process.c:306)
> [  880.960700] cpu_startup_entry (./arch/x86/include/asm/thread_info.h:162 include/linux/sched.h:2880 kernel/sched/idle.c:189 kernel/sched/idle.c:250 kernel/sched/idle.c:298)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? arch_cpu_idle_prepare (??:?)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? clockevents_register_device (kernel/time/clockevents.c:481)
> [  880.960700] start_secondary (arch/x86/kernel/smpboot.c:219)
> [  880.960700] ? set_cpu_sibling_map (arch/x86/kernel/smpboot.c:219)
> [ 880.960700] Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84
> All code
> ========
>    0:	00 00                	add    %al,(%rax)
>    2:	00 00                	add    %al,(%rax)
>    4:	00 55 48             	add    %dl,0x48(%rbp)
>    7:	89 e5                	mov    %esp,%ebp
>    9:	fa                   	cli
>    a:	5d                   	pop    %rbp
>    b:	c3                   	retq
>    c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   13:	00 00
>   15:	55                   	push   %rbp
>   16:	48 89 e5             	mov    %rsp,%rbp
>   19:	fb                   	sti
>   1a:	5d                   	pop    %rbp
>   1b:	c3                   	retq
>   1c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   23:	00 00
>   25:	55                   	push   %rbp
>   26:	48 89 e5             	mov    %rsp,%rbp
>   29:	fb                   	sti
>   2a:	f4                   	hlt
>   2b:*	5d                   	pop    %rbp		<-- trapping instruction
>   2c:	c3                   	retq
>   2d:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>   34:	00
>   35:	55                   	push   %rbp
>   36:	48 89 e5             	mov    %rsp,%rbp
>   39:	f4                   	hlt
>   3a:	5d                   	pop    %rbp
>   3b:	c3                   	retq
>   3c:	66                   	data16
>   3d:	0f                   	.byte 0xf
>   3e:	1f                   	(bad)
>   3f:	84 00                	test   %al,(%rax)
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	5d                   	pop    %rbp
>    1:	c3                   	retq
>    2:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>    9:	00
>    a:	55                   	push   %rbp
>    b:	48 89 e5             	mov    %rsp,%rbp
>    e:	f4                   	hlt
>    f:	5d                   	pop    %rbp
>   10:	c3                   	retq
>   11:	66                   	data16
>   12:	0f                   	.byte 0xf
>   13:	1f                   	(bad)
>   14:	84 00                	test   %al,(%rax)
> [  880.960700] NMI backtrace for cpu 27
> [  880.960700] CPU: 27 PID: 248 Comm: migration/27 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff8804c4cf8000 ti: ffff8804c3b00000 task.ti: ffff8804c3b00000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff8804c3b07b78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed0072423ee5 RCX: 1ffff1009899f2d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff8804c3b07bd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff88039211f738 R14: 0000000000000001 R15: ffff88039211f718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff8804c5200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 00000000029c4ff8 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff88039211f728 0000000000000282
> [  880.960700]  ffff880400000000 00ff8804c4cf8000 ffff8804c3b07bd8 dffffc0000000000
> [  880.960700]  ffff8804c5218440 ffff88039211f778 ffff88039211f718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 28
> [  880.960700] CPU: 28 PID: 0 Comm: swapper/28 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff88065d0c0000 ti: ffff88000eef0000 task.ti: ffff88000eef0000
> [  880.960700] RIP: native_safe_halt (./arch/x86/include/asm/irqflags.h:50)
> [  880.960700] RSP: 0018:ffff88000eef7d38  EFLAGS: 00000282
> [  880.960700] RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000000000
> [  880.960700] RDX: 1ffffffff4115884 RSI: 0000000000000001 RDI: ffffffffa08ac420
> [  880.960700] RBP: ffff88000eef7d38 R08: 0000000000000000 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffa31716b4
> [  880.960700] R13: ffff88000eef7fd8 R14: 0000000000000000 R15: ffff88000eef7fd8
> [  880.960700] FS:  0000000000000000(0000) GS:ffff8804ef200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 0000000000b34fb8 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffff88000eef7d68 ffffffff93160774 dffffc0000000000 ffffffffa31716b4
> [  880.960700]  ffff88000eef7fd8 0000000000000000 ffff88000eef7d78 ffffffff931629ef
> [  880.960700]  ffff88000eef7e68 ffffffff934018e0 0000000000000000 0000000000000000
> [  880.960700] Call Trace:
> [  880.960700] default_idle (./arch/x86/include/asm/paravirt.h:111 arch/x86/kernel/process.c:314)
> [  880.960700] arch_cpu_idle (arch/x86/kernel/process.c:306)
> [  880.960700] cpu_startup_entry (./arch/x86/include/asm/thread_info.h:162 include/linux/sched.h:2880 kernel/sched/idle.c:189 kernel/sched/idle.c:250 kernel/sched/idle.c:298)
> [  880.960700] ? arch_cpu_idle_prepare (??:?)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? clockevents_register_device (kernel/time/clockevents.c:481)
> [  880.960700] start_secondary (arch/x86/kernel/smpboot.c:219)
> [  880.960700] ? set_cpu_sibling_map (arch/x86/kernel/smpboot.c:219)
> [ 880.960700] Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84
> All code
> ========
>    0:	00 00                	add    %al,(%rax)
>    2:	00 00                	add    %al,(%rax)
>    4:	00 55 48             	add    %dl,0x48(%rbp)
>    7:	89 e5                	mov    %esp,%ebp
>    9:	fa                   	cli
>    a:	5d                   	pop    %rbp
>    b:	c3                   	retq
>    c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   13:	00 00
>   15:	55                   	push   %rbp
>   16:	48 89 e5             	mov    %rsp,%rbp
>   19:	fb                   	sti
>   1a:	5d                   	pop    %rbp
>   1b:	c3                   	retq
>   1c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   23:	00 00
>   25:	55                   	push   %rbp
>   26:	48 89 e5             	mov    %rsp,%rbp
>   29:	fb                   	sti
>   2a:	f4                   	hlt
>   2b:*	5d                   	pop    %rbp		<-- trapping instruction
>   2c:	c3                   	retq
>   2d:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>   34:	00
>   35:	55                   	push   %rbp
>   36:	48 89 e5             	mov    %rsp,%rbp
>   39:	f4                   	hlt
>   3a:	5d                   	pop    %rbp
>   3b:	c3                   	retq
>   3c:	66                   	data16
>   3d:	0f                   	.byte 0xf
>   3e:	1f                   	(bad)
>   3f:	84 00                	test   %al,(%rax)
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	5d                   	pop    %rbp
>    1:	c3                   	retq
>    2:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>    9:	00
>    a:	55                   	push   %rbp
>    b:	48 89 e5             	mov    %rsp,%rbp
>    e:	f4                   	hlt
>    f:	5d                   	pop    %rbp
>   10:	c3                   	retq
>   11:	66                   	data16
>   12:	0f                   	.byte 0xf
>   13:	1f                   	(bad)
>   14:	84 00                	test   %al,(%rax)
> [  880.960700] NMI backtrace for cpu 29
> [  880.960700] CPU: 29 PID: 0 Comm: swapper/29 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff88079d0b0000 ti: ffff88000eef8000 task.ti: ffff88000eef8000
> [  880.960700] RIP: native_safe_halt (./arch/x86/include/asm/irqflags.h:50)
> [  880.960700] RSP: 0018:ffff88000eeffd38  EFLAGS: 00000282
> [  880.960700] RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000000000
> [  880.960700] RDX: 1ffffffff4115884 RSI: 0000000000000001 RDI: ffffffffa08ac420
> [  880.960700] RBP: ffff88000eeffd38 R08: 0000000000000000 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffa31716b4
> [  880.960700] R13: ffff88000eefffd8 R14: 0000000000000000 R15: ffff88000eefffd8
> [  880.960700] FS:  0000000000000000(0000) GS:ffff880519000000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 00007f0f2b8e5210 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffff88000eeffd68 ffffffff93160774 dffffc0000000000 ffffffffa31716b4
> [  880.960700]  ffff88000eefffd8 0000000000000000 ffff88000eeffd78 ffffffff931629ef
> [  880.960700]  ffff88000eeffe68 ffffffff934018e0 ffff88000eeffde8 ffffffff9dbf7ec5
> [  880.960700] Call Trace:
> [  880.960700] default_idle (./arch/x86/include/asm/paravirt.h:111 arch/x86/kernel/process.c:314)
> [  880.960700] arch_cpu_idle (arch/x86/kernel/process.c:306)
> [  880.960700] cpu_startup_entry (./arch/x86/include/asm/thread_info.h:162 include/linux/sched.h:2880 kernel/sched/idle.c:189 kernel/sched/idle.c:250 kernel/sched/idle.c:298)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? arch_cpu_idle_prepare (??:?)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? clockevents_register_device (kernel/time/clockevents.c:481)
> [  880.960700] start_secondary (arch/x86/kernel/smpboot.c:219)
> [  880.960700] ? set_cpu_sibling_map (arch/x86/kernel/smpboot.c:219)
> [ 880.960700] Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84
> All code
> ========
>    0:	00 00                	add    %al,(%rax)
>    2:	00 00                	add    %al,(%rax)
>    4:	00 55 48             	add    %dl,0x48(%rbp)
>    7:	89 e5                	mov    %esp,%ebp
>    9:	fa                   	cli
>    a:	5d                   	pop    %rbp
>    b:	c3                   	retq
>    c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   13:	00 00
>   15:	55                   	push   %rbp
>   16:	48 89 e5             	mov    %rsp,%rbp
>   19:	fb                   	sti
>   1a:	5d                   	pop    %rbp
>   1b:	c3                   	retq
>   1c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   23:	00 00
>   25:	55                   	push   %rbp
>   26:	48 89 e5             	mov    %rsp,%rbp
>   29:	fb                   	sti
>   2a:	f4                   	hlt
>   2b:*	5d                   	pop    %rbp		<-- trapping instruction
>   2c:	c3                   	retq
>   2d:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>   34:	00
>   35:	55                   	push   %rbp
>   36:	48 89 e5             	mov    %rsp,%rbp
>   39:	f4                   	hlt
>   3a:	5d                   	pop    %rbp
>   3b:	c3                   	retq
>   3c:	66                   	data16
>   3d:	0f                   	.byte 0xf
>   3e:	1f                   	(bad)
>   3f:	84 00                	test   %al,(%rax)
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	5d                   	pop    %rbp
>    1:	c3                   	retq
>    2:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>    9:	00
>    a:	55                   	push   %rbp
>    b:	48 89 e5             	mov    %rsp,%rbp
>    e:	f4                   	hlt
>    f:	5d                   	pop    %rbp
>   10:	c3                   	retq
>   11:	66                   	data16
>   12:	0f                   	.byte 0xf
>   13:	1f                   	(bad)
>   14:	84 00                	test   %al,(%rax)
> [  880.960700] NMI backtrace for cpu 30
> [  880.960700] CPU: 30 PID: 269 Comm: migration/30 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff880542cf8000 ti: ffff880541b00000 task.ti: ffff880541b00000
> [  880.960700] RIP: multi_cpu_stop (kernel/stop_machine.c:192)
> [  880.960700] RSP: 0000:ffff880541b07b78  EFLAGS: 00000246
> [  880.960700] RAX: 0000000000000000 RBX: ffffed005ea54ee5 RCX: 1ffff100a859f2d5
> [  880.960700] RDX: 0000000000000000 RSI: ffffffff9e370ae0 RDI: ffffffffa31716b4
> [  880.960700] RBP: ffff880541b07bd8 R08: 0000000000000001 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> [  880.960700] R13: ffff8802f52a7738 R14: 0000000000000001 R15: ffff8802f52a7718
> [  880.960700] FS:  0000000000000000(0000) GS:ffff880543200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 00007f42552112c0 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffffffffa15a9540 ffffffff93532e90 ffff8802f52a7728 0000000000000282
> [  880.960700]  ffff880500000000 00ff880542cf8000 ffff880541b07bd8 dffffc0000000000
> [  880.960700]  ffff880543218440 ffff8802f52a7778 ffff8802f52a7718 ffffffff935335b0
> [  880.960700] Call Trace:
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? queue_stop_cpus_work (kernel/stop_machine.c:170)
> [  880.960700] cpu_stopper_thread (kernel/stop_machine.c:474)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] ? cpu_stop_should_run (include/linux/list.h:189 kernel/stop_machine.c:443)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? ikconfig_read_current (kernel/stop_machine.c:437)
> [  880.960700] ? trace_hardirqs_on_caller (kernel/locking/lockdep.c:2554 kernel/locking/lockdep.c:2601)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? cpu_stop_create (kernel/stop_machine.c:449)
> [  880.960700] smpboot_thread_fn (kernel/smpboot.c:161)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? schedule (./arch/x86/include/asm/bitops.h:311 (discriminator 1) kernel/sched/core.c:2824 (discriminator 1))
> [  880.960700] ? __kthread_parkme (kernel/kthread.c:164)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] ? sort_range (kernel/smpboot.c:105)
> [  880.960700] kthread (kernel/kthread.c:207)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [  880.960700] ret_from_fork (arch/x86/kernel/entry_64.S:565)
> [  880.960700] ? flush_kthread_work (kernel/kthread.c:176)
> [ 880.960700] Code: eb 27 0f 1f 00 41 83 fe 03 75 0a 80 7d cf 00 0f 85 50 01 00 00 f0 41 ff 4f 24 74 71 41 83 fe 04 0f 84 d7 00 00 00 45 89 f0 f3 90 <4c> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 74 08 3c 03 0f 8e f5
> All code
> ========
>    0:	eb 27                	jmp    0x29
>    2:	0f 1f 00             	nopl   (%rax)
>    5:	41 83 fe 03          	cmp    $0x3,%r14d
>    9:	75 0a                	jne    0x15
>    b:	80 7d cf 00          	cmpb   $0x0,-0x31(%rbp)
>    f:	0f 85 50 01 00 00    	jne    0x165
>   15:	f0 41 ff 4f 24       	lock decl 0x24(%r15)
>   1a:	74 71                	je     0x8d
>   1c:	41 83 fe 04          	cmp    $0x4,%r14d
>   20:	0f 84 d7 00 00 00    	je     0xfd
>   26:	45 89 f0             	mov    %r14d,%r8d
>   29:	f3 90                	pause
>   2b:*	4c 89 e8             	mov    %r13,%rax		<-- trapping instruction
>   2e:	48 c1 e8 03          	shr    $0x3,%rax
>   32:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>   37:	84 c0                	test   %al,%al
>   39:	74 08                	je     0x43
>   3b:	3c 03                	cmp    $0x3,%al
>   3d:	0f                   	.byte 0xf
>   3e:	8e f5                	mov    %ebp,%?
> 	...
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	4c 89 e8             	mov    %r13,%rax
>    3:	48 c1 e8 03          	shr    $0x3,%rax
>    7:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax
>    c:	84 c0                	test   %al,%al
>    e:	74 08                	je     0x18
>   10:	3c 03                	cmp    $0x3,%al
>   12:	0f                   	.byte 0xf
>   13:	8e f5                	mov    %ebp,%?
> 	...
> [  880.960700] NMI backtrace for cpu 31
> [  880.960700] CPU: 31 PID: 0 Comm: swapper/31 Not tainted 4.0.0-rc1-next-20150227-sasha-00039-gae4a688-dirty #1971
> [  880.960700] task: ffff88000f2d0000 ti: ffff88000f2d8000 task.ti: ffff88000f2d8000
> [  880.960700] RIP: native_safe_halt (./arch/x86/include/asm/irqflags.h:50)
> [  880.960700] RSP: 0000:ffff88000f2dfd38  EFLAGS: 00000282
> [  880.960700] RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 0000000000000000
> [  880.960700] RDX: 1ffffffff4115884 RSI: 0000000000000001 RDI: ffffffffa08ac420
> [  880.960700] RBP: ffff88000f2dfd38 R08: 0000000000000000 R09: 0000000000000000
> [  880.960700] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffa31716b4
> [  880.960700] R13: ffff88000f2dffd8 R14: 0000000000000000 R15: ffff88000f2dffd8
> [  880.960700] FS:  0000000000000000(0000) GS:ffff88056d200000(0000) knlGS:0000000000000000
> [  880.960700] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
> [  880.960700] CR2: 00007fff144e2980 CR3: 000000002082c000 CR4: 00000000000007a0
> [  880.960700] Stack:
> [  880.960700]  ffff88000f2dfd68 ffffffff93160774 dffffc0000000000 ffffffffa31716b4
> [  880.960700]  ffff88000f2dffd8 0000000000000000 ffff88000f2dfd78 ffffffff931629ef
> [  880.960700]  ffff88000f2dfe68 ffffffff934018e0 ffff88000f2dfde8 ffffffff9dbf7ec5
> [  880.960700] Call Trace:
> [  880.960700] default_idle (./arch/x86/include/asm/paravirt.h:111 arch/x86/kernel/process.c:314)
> [  880.960700] arch_cpu_idle (arch/x86/kernel/process.c:306)
> [  880.960700] cpu_startup_entry (./arch/x86/include/asm/thread_info.h:162 include/linux/sched.h:2880 kernel/sched/idle.c:189 kernel/sched/idle.c:250 kernel/sched/idle.c:298)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/paravirt.h:809 include/linux/spinlock_api_smp.h:162 kernel/locking/spinlock.c:191)
> [  880.960700] ? arch_cpu_idle_prepare (??:?)
> [  880.960700] ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/preempt.h:95 include/linux/spinlock_api_smp.h:163 kernel/locking/spinlock.c:191)
> [  880.960700] ? clockevents_register_device (kernel/time/clockevents.c:481)
> [  880.960700] start_secondary (arch/x86/kernel/smpboot.c:219)
> [  880.960700] ? set_cpu_sibling_map (arch/x86/kernel/smpboot.c:219)
> [ 880.960700] Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84
> All code
> ========
>    0:	00 00                	add    %al,(%rax)
>    2:	00 00                	add    %al,(%rax)
>    4:	00 55 48             	add    %dl,0x48(%rbp)
>    7:	89 e5                	mov    %esp,%ebp
>    9:	fa                   	cli
>    a:	5d                   	pop    %rbp
>    b:	c3                   	retq
>    c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   13:	00 00
>   15:	55                   	push   %rbp
>   16:	48 89 e5             	mov    %rsp,%rbp
>   19:	fb                   	sti
>   1a:	5d                   	pop    %rbp
>   1b:	c3                   	retq
>   1c:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
>   23:	00 00
>   25:	55                   	push   %rbp
>   26:	48 89 e5             	mov    %rsp,%rbp
>   29:	fb                   	sti
>   2a:	f4                   	hlt
>   2b:*	5d                   	pop    %rbp		<-- trapping instruction
>   2c:	c3                   	retq
>   2d:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>   34:	00
>   35:	55                   	push   %rbp
>   36:	48 89 e5             	mov    %rsp,%rbp
>   39:	f4                   	hlt
>   3a:	5d                   	pop    %rbp
>   3b:	c3                   	retq
>   3c:	66                   	data16
>   3d:	0f                   	.byte 0xf
>   3e:	1f                   	(bad)
>   3f:	84 00                	test   %al,(%rax)
> 
> Code starting with the faulting instruction
> ===========================================
>    0:	5d                   	pop    %rbp
>    1:	c3                   	retq
>    2:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
>    9:	00
>    a:	55                   	push   %rbp
>    b:	48 89 e5             	mov    %rsp,%rbp
>    e:	f4                   	hlt
>    f:	5d                   	pop    %rbp
>   10:	c3                   	retq
>   11:	66                   	data16
>   12:	0f                   	.byte 0xf
>   13:	1f                   	(bad)
>   14:	84 00                	test   %al,(%rax)
> 
> 
> Thanks,
> Sasha
> 


  parent reply	other threads:[~2015-03-06 11:28 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-02  7:45 sched: softlockups in multi_cpu_stop Sasha Levin
     [not found] ` <CAMiJ5CVWvUhGK=MWYB_CTNs901p=jsT4i5gkWTaHih7qdQdkFQ@mail.gmail.com>
2015-03-04  5:44   ` Rafael David Tinoco
2015-03-06 11:27 ` Sasha Levin [this message]
2015-03-06 12:32   ` Ingo Molnar
2015-03-06 14:34     ` Rafael David Tinoco
2015-03-06 14:45       ` Sasha Levin
2015-03-06 15:46         ` Sasha Levin
2015-03-06 17:19     ` Davidlohr Bueso
2015-03-06 18:02       ` Sasha Levin
2015-03-06 21:59         ` Sasha Levin
2015-03-06 18:57       ` Jason Low
2015-03-06 19:05         ` Linus Torvalds
2015-03-06 19:20           ` Davidlohr Bueso
2015-03-06 19:32             ` Linus Torvalds
2015-03-06 19:45               ` Davidlohr Bueso
2015-03-06 19:55               ` Davidlohr Bueso
2015-03-06 20:00                 ` Davidlohr Bueso
2015-03-06 21:42                 ` Linus Torvalds
2015-03-06 19:29           ` Jason Low
2015-03-06 21:12             ` Jason Low
2015-03-06 21:24               ` Linus Torvalds
2015-03-07  1:53                 ` Jason Low
2015-03-06 22:15               ` Davidlohr Bueso
2015-03-07  1:55                 ` Ming Lei
2015-03-07  2:07                   ` Davidlohr Bueso
2015-03-07  2:10                     ` Ming Lei
2015-03-07  2:26                       ` Davidlohr Bueso
2015-03-07  2:29                         ` Davidlohr Bueso
2015-03-07  2:55                           ` Ming Lei
2015-03-07  3:10                             ` Davidlohr Bueso
2015-03-07  3:19                               ` Ming Lei
2015-03-07  3:41                                 ` Davidlohr Bueso
2015-03-07  2:56                       ` Jason Low
2015-03-07  3:08                         ` Ming Lei
2015-03-07  3:10                           ` Davidlohr Bueso
2015-03-07  3:17                           ` Jason Low
2015-03-07  3:39                             ` Ming Lei
2015-03-07  3:53                               ` Jason Low
2015-03-07  1:58                 ` Jason Low
2015-03-07  4:31               ` Jason Low
2015-03-07  4:44                 ` Davidlohr Bueso
2015-03-07  6:45                   ` Jason Low
2015-03-07  5:54                 ` Ming Lei
2015-03-07  6:57                   ` Jason Low

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