rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 ticks this GP) idle=896/1/0x4000000000000002 softirq=78430/78430 fqs=1 
rcu: 	 (t=10981 jiffies g=101893 q=839)
NMI backtrace for cpu 1
CPU: 1 PID: 7779 Comm: kworker/1:3 Not tainted 5.0.0-rc4-next-20190201 #25
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:1234
 print_cpu_stall kernel/rcu/tree.c:1371 [inline]
 check_cpu_stall kernel/rcu/tree.c:1445 [inline]
 rcu_pending kernel/rcu/tree.c:3114 [inline]
 rcu_sched_clock_irq.cold+0x500/0xa4a kernel/rcu/tree.c:2555
 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:preempt_schedule_irq+0xab/0x140 kernel/sched/core.c:3715
Code: 00 00 e8 a8 54 49 fa e8 43 df 70 fa 4c 89 f0 48 c1 e8 03 80 3c 18 00 75 6c 48 83 3d fe 03 8e 01 00 74 5e fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 cb d5 ff ff 48 c7 c0 38 88 92 88 48 c1 e8 03 80
RSP: 0018:ffff88805980fad8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff1125108 RBX: dffffc0000000000 RCX: 1ffff1100b300dfe
RDX: 0000000000000000 RSI: ffff888059806fd0 RDI: ffff888059806f7c
RBP: ffff88805980faf8 R08: ffff888059806700 R09: ffff888059806ff0
R10: 0000000000000000 R11: 0000000000000000 R12: ffffed100b300ce0
R13: ffff888059806700 R14: ffffffff88928840 R15: 0000000000000000
 retint_kernel+0x1b/0x2d
RIP: 0010:delay_tsc+0x33/0xc0 arch/x86/lib/delay.c:68
Code: bf 01 00 00 00 41 55 41 54 53 e8 d8 ac 4a fa e8 13 ea 29 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 b3 ac 4a fa e8 ee e9 29 fc 44 39 e8 75 36 0f 01
RSP: 0018:ffff88805980fbb0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02
RAX: 0000000080000000 RBX: 0000024ac7bf7b1b RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff832d13c8 RDI: 0000000000000001
RBP: ffff88805980fbd0 R08: ffff888059806700 R09: 0000000000000040
R10: 0000000000000040 R11: ffffffff88a42a27 R12: 0000024ac7bf682c
R13: 0000000000000001 R14: 0000000000002ced R15: 0000000000000cb2
 __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:722
 srcu_advance_state kernel/rcu/srcutree.c:1159 [inline]
 process_srcu+0x329/0xe20 kernel/rcu/srcutree.c:1254
 process_one_work+0x98e/0x1790 kernel/workqueue.c:2257
 worker_thread+0x98/0xe40 kernel/workqueue.c:2403
 kthread+0x357/0x430 kernel/kthread.c:247
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352