rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=c26/1/0x4000000000000004 softirq=178212/178213 fqs=5201 
	(t=10500 jiffies g=247645 q=7514)
NMI backtrace for cpu 0
CPU: 0 PID: 26395 Comm: kworker/0:13 Not tainted 5.3.0-rc8+ #0
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: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:1110 [inline]
 smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
RIP: 0010:hhf_dequeue+0x5bc/0xa20 net/sched/sch_hhf.c:438
Code: e8 03 42 0f b6 14 20 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 3f 04 00 00 45 0f af b5 14 03 00 00 48 89 df 45 01 fe <44> 89 73 10 e8 bb cc 77 fd 31 ff 41 89 c6 89 c6 e8 ef 05 ac fb 45
RSP: 0018:ffff8880ae808e98 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000007 RBX: ffff8880a997d978 RCX: ffffffff85c66b39
RDX: 0000000000000000 RSI: ffffffff85c67006 RDI: ffff8880a997d978
RBP: ffff8880ae808ee8 R08: ffff88809a368180 R09: 0000000000000000
R10: fffffbfff134afaf R11: ffff88809a368180 R12: dffffc0000000000
R13: ffff8880a997d680 R14: 0000000000000000 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
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 br_forward_finish+0xfa/0x400 net/bridge/br_forward.c:65
 NF_HOOK include/linux/netfilter.h:305 [inline]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 __br_forward+0x641/0xb00 net/bridge/br_forward.c:109
 deliver_clone+0x61/0xc0 net/bridge/br_forward.c:125
 maybe_deliver+0x2c7/0x390 net/bridge/br_forward.c:181
 br_flood+0x13a/0x3d0 net/bridge/br_forward.c:223
 br_dev_xmit+0x98c/0x15a0 net/bridge/br_device.c:100
 __netdev_start_xmit include/linux/netdevice.h:4406 [inline]
 netdev_start_xmit include/linux/netdevice.h:4420 [inline]
 xmit_one net/core/dev.c:3280 [inline]
 dev_hard_start_xmit+0x1a3/0x9c0 net/core/dev.c:3296
 __dev_queue_xmit+0x2b15/0x3650 net/core/dev.c:3869
 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]
 NF_HOOK include/linux/netfilter.h:299 [inline]
 mld_sendpack+0x9c7/0xea0 net/ipv6/mcast.c:1682
 mld_send_cr net/ipv6/mcast.c:1978 [inline]
 mld_ifc_timer_expire+0x449/0x8a0 net/ipv6/mcast.c:2477
 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1322
 expire_timers kernel/time/timer.c:1366 [inline]
 __run_timers kernel/time/timer.c:1685 [inline]
 __run_timers kernel/time/timer.c:1653 [inline]
 run_timer_softirq+0x697/0x17a0 kernel/time/timer.c:1698
 __do_softirq+0x262/0x98c kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x19b/0x1e0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:537 [inline]
 smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
 </IRQ>
RIP: 0010:__preempt_count_sub arch/x86/include/asm/preempt.h:84 [inline]
RIP: 0010:preempt_count_sub+0x5a/0x150 kernel/sched/core.c:3650
Code: 85 e8 00 00 00 8b 0d 75 8f 3c 09 85 c9 75 1b 65 8b 05 f2 3b b3 7e 89 c2 81 e2 ff ff ff 7f 39 d3 7f 14 81 fb fe 00 00 00 76 64 <f7> db 65 01 1d d5 3b b3 7e 5b 5d c3 e8 35 70 eb 01 85 c0 74 f4 48
RSP: 0018:ffff88806fcc7b98 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
RAX: 0000000080000001 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff833e395c RDI: 0000000000000001
RBP: ffff88806fcc7ba0 R08: ffff88809a368180 R09: 0000000000000040
R10: 0000000000000040 R11: ffffffff88e53d27 R12: 000002bc64163108
R13: 0000000000000000 R14: 0000000000002ced R15: 0000000000002039
 delay_tsc+0x6b/0xc0 arch/x86/lib/delay.c:66
 __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