rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10500 ticks this GP) idle=092/1/0x4000000000000002 softirq=62746/62746 fqs=0 
	(t=10500 jiffies g=88725 q=1777)
rcu: rcu_preempt kthread starved for 10500 jiffies! g88725 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     I29256    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3254 [inline]
 __schedule+0x755/0x1580 kernel/sched/core.c:3880
 schedule+0xd9/0x260 kernel/sched/core.c:3947
 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1807
 rcu_gp_fqs_loop kernel/rcu/tree.c:1611 [inline]
 rcu_gp_kthread+0x9b2/0x18c0 kernel/rcu/tree.c:1768
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 0
CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.3.0-rc8+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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:hhf_dequeue+0x532/0xa20 net/sched/sch_hhf.c:435
Code: 45 b8 4c 8b 75 c8 42 80 3c 20 00 0f 85 3a 04 00 00 49 8b 85 90 03 00 00 48 39 45 c8 0f 85 4b fb ff ff 45 31 ff e9 b0 02 00 00 <e8> 39 15 ac fb 48 8d 43 f0 41 be 01 00 00 00 49 8d 95 c0 02 00 00
RSP: 0018:ffff8880a98b69a8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000301 RBX: ffff888096457538 RCX: ffffffff85c65b39
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: ffff8880a98b69f8 R08: ffff8880a98a2240 R09: 0000000000000000
R10: fffffbfff134afaf R11: ffff8880a98a2240 R12: dffffc0000000000
R13: ffff888096457240 R14: ffff8880964575d0 R15: 0000000000000000
 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
 br_dev_queue_push_xmit+0x3f3/0x5c0 net/bridge/br_forward.c:52
 br_nf_dev_queue_xmit+0x34e/0x1470 net/bridge/br_netfilter_hooks.c:796
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 br_nf_post_routing+0x1502/0x1d30 net/bridge/br_netfilter_hooks.c:844
 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline]
 nf_hook_slow+0xbc/0x1e0 net/netfilter/core.c:512
 nf_hook include/linux/netfilter.h:260 [inline]
 NF_HOOK include/linux/netfilter.h:303 [inline]
 br_forward_finish+0x215/0x400 net/bridge/br_forward.c:65
 br_nf_hook_thresh+0x2e9/0x370 net/bridge/br_netfilter_hooks.c:1015
 br_nf_forward_finish+0x66c/0xa90 net/bridge/br_netfilter_hooks.c:560
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 br_nf_forward_ip net/bridge/br_netfilter_hooks.c:630 [inline]
 br_nf_forward_ip+0xc74/0x21e0 net/bridge/br_netfilter_hooks.c:571
 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline]
 nf_hook_slow+0xbc/0x1e0 net/netfilter/core.c:512
 nf_hook include/linux/netfilter.h:260 [inline]
 NF_HOOK include/linux/netfilter.h:303 [inline]
 __br_forward+0x393/0xb00 net/bridge/br_forward.c:109
 deliver_clone+0x61/0xc0 net/bridge/br_forward.c:125
 br_flood+0x325/0x3d0 net/bridge/br_forward.c:232
 br_handle_frame_finish+0xb46/0x1670 net/bridge/br_input.c:162
 br_nf_hook_thresh+0x2e9/0x370 net/bridge/br_netfilter_hooks.c:1015
 br_nf_pre_routing_finish_ipv6+0x6fb/0xd80 net/bridge/br_netfilter_ipv6.c:206
 NF_HOOK include/linux/netfilter.h:305 [inline]
 br_nf_pre_routing_ipv6+0x456/0x832 net/bridge/br_netfilter_ipv6.c:236
 br_nf_pre_routing+0x1743/0x2355 net/bridge/br_netfilter_hooks.c:501
 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:223 [inline]
 br_handle_frame+0x806/0x133e net/bridge/br_input.c:348
 __netif_receive_skb_core+0xfc1/0x3060 net/core/dev.c:4905
 __netif_receive_skb_one_core+0xa8/0x1a0 net/core/dev.c:5002
 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5118
 process_backlog+0x206/0x750 net/core/dev.c:5929
 napi_poll net/core/dev.c:6352 [inline]
 net_rx_action+0x4d6/0x1030 net/core/dev.c:6418
 __do_softirq+0x262/0x98c kernel/softirq.c:292
 run_ksoftirqd kernel/softirq.c:603 [inline]
 run_ksoftirqd+0x8e/0x110 kernel/softirq.c:595
 smpboot_thread_fn+0x6a3/0xa40 kernel/smpboot.c:165
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352