rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 GPs behind) idle=aa6/0/0x3 softirq=10720/10721 fqs=28 
	(t=10500 jiffies g=10345 q=51)
rcu: rcu_preempt kthread starved for 10444 jiffies! g10345 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    29320    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 1
CPU: 1 PID: 0 Comm: swapper/1 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: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:__read_once_size include/linux/compiler.h:199 [inline]
RIP: 0010:list_empty include/linux/list.h:268 [inline]
RIP: 0010:hhf_dequeue+0x58/0xa20 net/sched/sch_hhf.c:427
Code: 48 c1 e8 03 4c 01 e0 48 89 45 c0 49 8d 85 90 03 00 00 48 89 45 c8 48 c1 e8 03 48 89 45 b8 e8 5f 1a ac fb 48 8b 45 c0 80 38 00 <0f> 85 a8 07 00 00 48 8b 75 d0 49 8b 85 80 03 00 00 49 89 f6 48 39
RSP: 0018:ffff8880ae909038 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffed10110b8d90 RBX: ffff8880885c6bf8 RCX: ffffffff85c660f9
RDX: 0000000000000100 RSI: ffffffff85c65ad1 RDI: ffff8880885c6c00
RBP: ffff8880ae909088 R08: ffff8880a98d6340 R09: 0000000000000000
R10: fffffbfff134afaf R11: ffff8880a98d6340 R12: dffffc0000000000
R13: ffff8880885c6900 R14: ffff8880885c6c98 R15: ffff8880885c6c90
 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_hh_output include/net/neighbour.h:500 [inline]
 neigh_output include/net/neighbour.h:509 [inline]
 ip_finish_output2+0x1726/0x2570 net/ipv4/ip_output.c:228
 __ip_finish_output net/ipv4/ip_output.c:308 [inline]
 __ip_finish_output+0x5fc/0xb90 net/ipv4/ip_output.c:290
 ip_finish_output+0x38/0x1f0 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip_output+0x21f/0x640 net/ipv4/ip_output.c:432
 dst_output include/net/dst.h:436 [inline]
 ip_local_out+0xbb/0x190 net/ipv4/ip_output.c:125
 igmpv3_sendpack+0x1b5/0x2c0 net/ipv4/igmp.c:426
 igmpv3_send_cr net/ipv4/igmp.c:721 [inline]
 igmp_ifc_timer_expire+0x687/0xa00 net/ipv4/igmp.c:809
 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:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: b8 73 6e fa eb 8a 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d 24 1b 4a 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 14 1b 4a 00 fb f4 <c3> 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 2e 33 22 fa e8 b9
RSP: 0018:ffff8880a98e7d68 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff11a5e8d RBX: ffff8880a98d6340 RCX: 1ffffffff134b5ee
RDX: dffffc0000000000 RSI: ffffffff8177f18e RDI: ffffffff873e050c
RBP: ffff8880a98e7d98 R08: ffff8880a98d6340 R09: ffffed101531ac69
R10: ffffed101531ac68 R11: ffff8880a98d6347 R12: dffffc0000000000
R13: ffffffff89a57d78 R14: 0000000000000000 R15: 0000000000000001
 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571
 default_idle_call+0x84/0xb0 kernel/sched/idle.c:94
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x413/0x760 kernel/sched/idle.c:263
 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:354
 start_secondary+0x315/0x430 arch/x86/kernel/smpboot.c:264
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241