rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 GPs behind) idle=0be/1/0x4000000000000002 softirq=18619/18623 fqs=0 
	(t=11231 jiffies g=19573 q=176)
rcu: rcu_preempt kthread starved for 11231 jiffies! g19573 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     I27160    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3254 [inline]
 __schedule+0x8b6/0xcd0 kernel/sched/core.c:3880
 schedule+0x131/0x1e0 kernel/sched/core.c:3944
 schedule_timeout+0x19d/0x2b0 kernel/time/timer.c:1807
 rcu_gp_fqs_loop kernel/rcu/tree.c:1611 [inline]
 rcu_gp_kthread+0x1008/0x18d0 kernel/rcu/tree.c:1768
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 1
CPU: 1 PID: 3612 Comm: kworker/1:2 Not tainted 5.3.0-rc2+ #59
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+0x1d8/0x2f8 lib/dump_stack.c:113
 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x15a/0x220 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:2736 [inline]
 rcu_sched_clock_irq+0xb95/0x16d0 kernel/rcu/tree.c:2183
 update_process_times+0x134/0x190 kernel/time/timer.c:1639
 tick_sched_handle kernel/time/tick-sched.c:167 [inline]
 tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1296
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x471/0x8c0 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1068 [inline]
 smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1093
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:828
 </IRQ>
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x5f/0x80 kernel/locking/spinlock.c:199
Code: 00 00 00 00 fc ff df 80 3c 08 00 74 0c 48 c7 c7 90 87 ca 88 e8 02 1f 01 fa 48 83 3d ca 1a 19 01 00 74 26 fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 27 27 a2 f9 65 8b 05 ec 90 50 78 85 c0 74 03 5b
RSP: 0018:ffff88809b91fb48 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff11950f2 RBX: ffffffff88d014e0 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffffff81644cda RDI: ffffffff87b16c97
RBP: ffff88809b91fb50 R08: ffffffff817d8974 R09: fffffbfff11a029d
R10: fffffbfff11a029d R11: 0000000000000000 R12: ffffffff88d01178
R13: dffffc0000000000 R14: 00000000000003be R15: ffffffff88d014e0
 srcu_reschedule+0x9a/0xf0 kernel/rcu/srcutree.c:1220
 process_srcu+0x566/0xd20 kernel/rcu/srcutree.c:1238
 process_one_work+0x83b/0x1150 kernel/workqueue.c:2269
 worker_thread+0xc01/0x1630 kernel/workqueue.c:2415
 kthread+0x332/0x350 kernel/kthread.c:255