rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=c12/1/0x4000000000000002 softirq=196797/196798 fqs=5249 
	(t=10502 jiffies g=328597 q=2144)
NMI backtrace for cpu 0
CPU: 0 PID: 26414 Comm: kworker/0:6 Not tainted 5.3.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events rt6_probe_deferred
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:1639
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167
 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1296
 __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
 __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1451
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1106 [inline]
 smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1131
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 </IRQ>
RIP: 0010:__list_add include/linux/list.h:65 [inline]
RIP: 0010:list_add_tail include/linux/list.h:93 [inline]
RIP: 0010:list_move_tail include/linux/list.h:214 [inline]
RIP: 0010:hhf_dequeue+0x6c4/0xa20 net/sched/sch_hhf.c:439
Code: 03 00 00 48 89 d8 49 89 9d 98 03 00 00 48 c1 e8 03 42 80 3c 20 00 0f 85 b4 02 00 00 48 8b 45 c8 48 8d 7b 08 48 89 03 48 89 f8 <48> c1 e8 03 42 80 3c 20 00 0f 85 8d 02 00 00 4c 89 f8 4c 89 7b 08
RSP: 0018:ffff8880960c7438 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffff888095cda300 RBX: ffff888095cda2f8 RCX: ffffffff85c7e179
RDX: 0000000000000000 RSI: ffffffff85c7e18b RDI: ffff888095cda300
RBP: ffff8880960c7488 R08: ffff888063d2c440 R09: fffffbfff14e9555
R10: ffff888063d2cdc0 R11: ffff888063d2c440 R12: dffffc0000000000
R13: ffff888095cda000 R14: ffff888095cda398 R15: ffff888095cda390
 dequeue_skb net/sched/sch_generic.c:258 [inline]
 qdisc_restart net/sched/sch_generic.c:361 [inline]
 __qdisc_run+0x1e7/0x19d0 net/sched/sch_generic.c:379
 __dev_xmit_skb net/core/dev.c:3533 [inline]
 __dev_queue_xmit+0x16f1/0x3650 net/core/dev.c:3838
 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902
 neigh_resolve_output net/core/neighbour.c:1490 [inline]
 neigh_resolve_output+0x5a5/0x970 net/core/neighbour.c:1470
 neigh_output include/net/neighbour.h:511 [inline]
 ip6_finish_output2+0x1034/0x2520 net/ipv6/ip6_output.c:116
 __ip6_finish_output+0x444/0xa50 net/ipv6/ip6_output.c:142
 ip6_finish_output+0x38/0x1f0 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0x235/0x7c0 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 NF_HOOK include/linux/netfilter.h:305 [inline]
 ndisc_send_skb+0xf29/0x1450 net/ipv6/ndisc.c:505
 ndisc_send_ns+0x3a9/0x850 net/ipv6/ndisc.c:647
 rt6_probe_deferred+0xe3/0x1a0 net/ipv6/route.c:615
 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