rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 ticks this GP) idle=312/1/0x4000000000000002 softirq=281370/281370 fqs=0 
	(t=11127 jiffies g=482173 q=336)
rcu: rcu_preempt kthread starved for 11127 jiffies! g482173 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     I29296    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:2818 [inline]
 __schedule+0x7cb/0x1560 kernel/sched/core.c:3445
 schedule+0xa8/0x260 kernel/sched/core.c:3509
 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1807
 rcu_gp_fqs_loop kernel/rcu/tree.c:1589 [inline]
 rcu_gp_kthread+0x9b2/0x18b0 kernel/rcu/tree.c:1746
 kthread+0x354/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 1
CPU: 1 PID: 22130 Comm: kworker/1:6 Not tainted 5.2.0-rc4+ #29
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: rcu_gp process_srcu
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x183/0x1cf kernel/rcu/tree_stall.h:254
 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:529 [inline]
 rcu_pending kernel/rcu/tree.c:2625 [inline]
 rcu_sched_clock_irq.cold+0x4d1/0xbfd kernel/rcu/tree.c:2161
 update_process_times+0x32/0x80 kernel/time/timer.c:1639
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167
 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1298
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x33b/0xdd0 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 smp_apic_timer_interrupt+0x111/0x550 arch/x86/kernel/apic/apic.c:1066
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:806
 </IRQ>
RIP: 0010:preempt_schedule_irq+0xab/0x140 kernel/sched/core.c:3693
Code: 00 00 e8 b8 fb 31 fa e8 b3 89 5a fa 4c 89 f0 48 c1 e8 03 80 3c 18 00 75 6c 48 83 3d ce dd 96 01 00 74 5e fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 4b dc ff ff 48 c7 c0 f8 73 b2 88 48 c1 e8 03 80
RSP: 0018:ffff88808bfd7b08 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff1164e80 RBX: dffffc0000000000 RCX: 1ffff110118019c9
RDX: 0000000000000000 RSI: ffff88808c00ce28 RDI: ffff88808c00cdfc
RBP: ffff88808bfd7b28 R08: ffff88808c00c580 R09: ffff88808c00ce48
R10: 0000000000000000 R11: 0000000000000000 R12: ffffed10118018b0
R13: ffff88808c00c580 R14: ffffffff88b27400 R15: 0000000000000000
 retint_kernel+0x1b/0x2b
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:767 [inline]
RIP: 0010:queue_delayed_work_on+0x11d/0x200 kernel/workqueue.c:1678
Code: 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 d8 00 00 00 48 83 3d e3 df 67 07 00 0f 84 9a 00 00 00 e8 b8 12 26 00 48 89 df 57 9d <0f> 1f 44 00 00 e8 a9 12 26 00 44 89 f8 48 83 c4 10 5b 41 5c 41 5d
RSP: 0018:ffff88808bfd7be0 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff02
RAX: ffff88808c00c580 RBX: 0000000000000293 RCX: 1ffff110118019c9
RDX: 0000000000000000 RSI: ffffffff814a9418 RDI: 0000000000000293
RBP: ffff88808bfd7c18 R08: ffff88808c00c580 R09: ffff88808c00ce48
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000200
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
 queue_delayed_work include/linux/workqueue.h:509 [inline]
 srcu_reschedule+0xd7/0x130 kernel/rcu/srcutree.c:1225
 process_srcu+0x125/0xe20 kernel/rcu/srcutree.c:1238
 process_one_work+0x989/0x1790 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x354/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352