rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (10499 ticks this GP) idle=c4e/1/0x4000000000000002 softirq=137436/137437 fqs=5247 (t=10501 jiffies g=234073 q=1337) NMI backtrace for cpu 0 CPU: 0 PID: 8961 Comm: kworker/0:3 Not tainted 5.3.0-rc6-next-20190830 #75 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events rt6_probe_deferred Call Trace: __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:2795 [inline] rcu_sched_clock_irq.cold+0x4fd/0xc12 kernel/rcu/tree.c:2244 update_process_times+0x2d/0x70 kernel/time/timer.c:1724 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1299 __run_hrtimer kernel/time/hrtimer.c:1504 [inline] __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1566 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1628 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 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+0x6c1/0xa20 net/sched/sch_hhf.c:439 Code: 0f 85 08 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 RSP: 0018:ffff88805d8aee28 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffff8880a0726390 RBX: ffff8880a07262f8 RCX: ffffffff85cb6f79 RDX: 0000000000000000 RSI: ffffffff85cb6f8b RDI: ffff8880a0726300 RBP: ffff88805d8aee78 R08: ffff88805d8a64c0 R09: fffffbfff14ed341 R10: ffff88805d8a6ea0 R11: ffff88805d8a64c0 R12: dffffc0000000000 R13: ffff8880a0726000 R14: ffff8880a0726398 R15: ffff8880a0726390 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+0x16f1/0x37c0 net/core/dev.c:3838 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902 br_dev_queue_push_xmit+0x3f3/0x5e0 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:4419 [inline] netdev_start_xmit include/linux/netdevice.h:4433 [inline] xmit_one net/core/dev.c:3280 [inline] dev_hard_start_xmit+0x1a3/0x9c0 net/core/dev.c:3296 __dev_queue_xmit+0x2b82/0x37c0 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] ip6_finish_output2+0xf58/0x2550 net/ipv6/ip6_output.c:116 __ip6_finish_output+0x444/0xaa0 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+0x235/0x7f0 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+0xf29/0x14a0 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