rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 GPs behind) idle=d62/1/0x4000000000000002 softirq=103222/103225 fqs=0 
rcu: 	 (t=11243 jiffies g=111797 q=241)
NMI backtrace for cpu 1
CPU: 1 PID: 29033 Comm: kworker/1:4 Not tainted 5.1.0-rc6+ #89
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.c:1223
 print_cpu_stall kernel/rcu/tree.c:1360 [inline]
 check_cpu_stall kernel/rcu/tree.c:1434 [inline]
 rcu_pending kernel/rcu/tree.c:3103 [inline]
 rcu_sched_clock_irq.cold+0x500/0xa4a kernel/rcu/tree.c:2544
 update_process_times+0x32/0x80 kernel/time/timer.c:1635
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x33e/0xde0 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
 smp_apic_timer_interrupt+0x120/0x570 arch/x86/kernel/apic/apic.c:1060
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
 </IRQ>
RIP: 0010:rdtsc_ordered arch/x86/include/asm/msr.h:236 [inline]
RIP: 0010:delay_tsc+0x4a/0xc0 arch/x86/lib/delay.c:61
Code: 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 b1 3f fa e8 0e 41 23 fc 44 39 e8 75 36 0f 01 f9 <66> 90 48 c1 e2 20 48 89 d3 48 09 c3 48 89 d8 4c 29 e0 4c 39 f0 73
RSP: 0018:ffff88805c3c7bb0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 00000000a30326f7 RBX: 000001b1a3032607 RCX: 0000000000000001
RDX: 00000000000001b1 RSI: ffffffff833182bc RDI: 0000000000000005
RBP: ffff88805c3c7bd0 R08: ffff888055f9a580 R09: 0000000000000040
R10: 0000000000000040 R11: ffffffff88a44667 R12: 000001b1a30307ca
R13: 0000000000000001 R14: 0000000000002ced R15: 0000000000002631
 __delay arch/x86/lib/delay.c:161 [inline]
 __const_udelay+0x5f/0x80 arch/x86/lib/delay.c:175
 try_check_zero+0x201/0x330 kernel/rcu/srcutree.c:709
 srcu_advance_state kernel/rcu/srcutree.c:1146 [inline]
 process_srcu+0x329/0xe20 kernel/rcu/srcutree.c:1241
 process_one_work+0x98e/0x1790 kernel/workqueue.c:2269
 worker_thread+0x98/0xe40 kernel/workqueue.c:2415
 kthread+0x357/0x430 kernel/kthread.c:253
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352