rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 GPs behind) idle=fca/1/0x4000000000000002 softirq=520380/520386 fqs=0 
	(t=11226 jiffies g=489325 q=173)
NMI backtrace for cpu 0
CPU: 0 PID: 9617 Comm: kworker/0:1 Not tainted 5.3.0-rc3-next-20190806 #60
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+0x70/0xb2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x23b/0x28b 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:2736 [inline]
 rcu_sched_clock_irq.cold+0x4dd/0xc13 kernel/rcu/tree.c:2183
 update_process_times+0x32/0x80 kernel/time/timer.c:1724
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167
 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1299
 __run_hrtimer kernel/time/hrtimer.c:1493 [inline]
 __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1555
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1617
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1068 [inline]
 smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1093
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:828
 </IRQ>
RIP: 0010:preempt_schedule_irq+0xab/0x160 kernel/sched/core.c:4169
Code: 00 00 e8 78 4c 0f fa e8 e3 cf 38 fa 4c 89 f0 48 c1 e8 03 80 3c 18 00 75 7d 48 83 3d 3e 20 94 01 00 74 6f fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 cb db ff ff 48 c7 c0 a8 f6 d2 88 48 c1 e8 03 80
RSP: 0018:ffff8880608f7ad8 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff11a5ed6 RBX: dffffc0000000000 RCX: 1ffffffff134c9ce
RDX: 0000000000000000 RSI: ffffffff8177a69e RDI: ffffffff873ed65d
RBP: ffff8880608f7af8 R08: ffff8880a0b8e500 R09: ffffed1015d06afd
R10: ffffed1015d06afc R11: ffff8880ae8357e3 R12: ffffed1014171ca0
R13: ffff8880a0b8e500 R14: ffffffff88d2f6b0 R15: 0000000000000000
 retint_kernel+0x1b/0x2b
RIP: 0010:delay_tsc+0x33/0xc0 arch/x86/lib/delay.c:68
Code: bf 01 00 00 00 41 55 41 54 53 e8 b8 9e 10 fa e8 83 b1 00 fc 41 89 c5 0f 01 f9 66 90 48 c1 e2 20 48 09 c2 49 89 d4 eb 16 f3 90 <bf> 01 00 00 00 e8 93 9e 10 fa e8 5e b1 00 fc 44 39 e8 75 36 0f 01
RSP: 0018:ffff8880608f7bb0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02
RAX: 0000000080000000 RBX: 0000058f65b1229c RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff833e35dc RDI: 0000000000000001
RBP: ffff8880608f7bd0 R08: ffff8880a0b8e500 R09: 0000000000000040
R10: 0000000000000040 R11: ffffffff88e545a7 R12: 0000058f65b105ff
R13: 0000000000000000 R14: 0000000000002ced R15: 0000000000001fde
 __delay arch/x86/lib/delay.c:161 [inline]
 __const_udelay+0x59/0x80 arch/x86/lib/delay.c:175
 try_check_zero+0x201/0x330 kernel/rcu/srcutree.c:705
 srcu_advance_state kernel/rcu/srcutree.c:1142 [inline]
 process_srcu+0x329/0xe20 kernel/rcu/srcutree.c:1237
 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352