rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=38a/1/0x4000000000000002 softirq=9356/9357 fqs=16 (t=10500 jiffies g=6609 q=236) rcu: rcu_preempt kthread starved for 10468 jiffies! g6609 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29128 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3254 [inline] __schedule+0x877/0xc50 kernel/sched/core.c:3880 schedule+0x131/0x1e0 kernel/sched/core.c:3947 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1807 rcu_gp_fqs_loop kernel/rcu/tree.c:1611 [inline] rcu_gp_kthread+0xef8/0x1790 kernel/rcu/tree.c:1768 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 1 CPU: 1 PID: 17 Comm: kworker/1:0 Not tainted 5.3.0-rc8+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d8/0x2f8 lib/dump_stack.c:113 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x15a/0x220 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+0xb95/0x16d0 kernel/rcu/tree.c:2183 update_process_times+0x134/0x190 kernel/time/timer.c:1639 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1296 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x403/0x850 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:__list_add_valid+0x6/0xc0 lib/list_debug.c:22 Code: 1f fe 0f 0b 55 48 89 e5 53 48 89 fb e8 23 ca 1f fe 48 c7 c7 e6 4d 3f 88 48 89 de e8 44 fd ff ff 5b 5d c3 90 55 48 89 e5 41 57 <41> 56 41 55 41 54 53 49 89 d6 49 89 f4 49 89 ff 49 bd 00 00 00 00 RSP: 0018:ffff8880a98ff1c0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 1ffff1101305c90a RBX: 1ffff1101305c90b RCX: ffff8880a98f4480 RDX: ffff8880982e4850 RSI: ffff8880982e4850 RDI: ffff8880982e47b8 RBP: ffff8880a98ff1c8 R08: ffffffff860c5d6a R09: 0000000000000000 R10: fffffbfff117be8d R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8880982e44c0 R14: ffff8880982e4850 R15: ffff8880982e4840 __list_add include/linux/list.h:60 [inline] list_add_tail include/linux/list.h:93 [inline] list_move_tail include/linux/list.h:214 [inline] hhf_dequeue+0x535/0xaa0 net/sched/sch_hhf.c:439 dequeue_skb net/sched/sch_generic.c:258 [inline] qdisc_restart net/sched/sch_generic.c:361 [inline] __qdisc_run+0x217/0x1b30 net/sched/sch_generic.c:379 __dev_xmit_skb net/core/dev.c:3533 [inline] __dev_queue_xmit+0x1161/0x3020 net/core/dev.c:3838 dev_queue_xmit+0x17/0x20 net/core/dev.c:3902 br_dev_queue_push_xmit+0x551/0x650 net/bridge/br_forward.c:52 NF_HOOK include/linux/netfilter.h:305 [inline] br_forward_finish net/bridge/br_forward.c:65 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] __br_forward+0x439/0x720 net/bridge/br_forward.c:109 deliver_clone net/bridge/br_forward.c:125 [inline] maybe_deliver net/bridge/br_forward.c:181 [inline] br_flood+0x52e/0x840 net/bridge/br_forward.c:223 br_dev_xmit+0xcb6/0x1100 net/bridge/br_device.c:96 __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+0x1c1/0x3f0 net/core/dev.c:3296 __dev_queue_xmit+0x1e86/0x3020 net/core/dev.c:3869 dev_queue_xmit+0x17/0x20 net/core/dev.c:3902 neigh_resolve_output+0x60c/0x6b0 net/core/neighbour.c:1490 neigh_output include/net/neighbour.h:511 [inline] ip6_finish_output2+0x102c/0x13d0 net/ipv6/ip6_output.c:116 __ip6_finish_output+0x693/0x910 net/ipv6/ip6_output.c:142 ip6_finish_output+0x52/0x1e0 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0x26f/0x390 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+0xa35/0xe40 net/ipv6/ndisc.c:504 ndisc_send_ns+0x5ce/0x7b0 net/ipv6/ndisc.c:646 addrconf_dad_work+0xe40/0x1c20 net/ipv6/addrconf.c:4120 process_one_work+0x7ef/0x10e0 kernel/workqueue.c:2269 worker_thread+0xc01/0x1630 kernel/workqueue.c:2415 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352