rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=0ea/1/0x4000000000000002 softirq=8787/8788 fqs=18 (t=10501 jiffies g=6657 q=46) rcu: rcu_preempt kthread starved for 10466 jiffies! g6657 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt I28896 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 0 CPU: 0 PID: 12 Comm: kworker/0:1 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:1106 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1131 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:__list_add_valid+0x4e/0xc0 lib/list_debug.c:26 Code: 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 26 c5 58 fe 48 8b 13 4c 39 e2 75 4f 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 e7 e8 08 c5 58 fe 49 8b 14 24 4c 39 f2 75 46 4d 39 e7 RSP: 0018:ffff8880aea08fc0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 1ffff11011e7c872 RBX: ffff88808f3e4398 RCX: ffff8880a98a4300 RDX: ffff88808f3e4390 RSI: ffff88808f3e4390 RDI: ffff88808f3e42f8 RBP: ffff8880aea08fe8 R08: ffffffff860c5d6a R09: 0000000000000000 R10: fffffbfff117be8d R11: 0000000000000000 R12: ffff88808f3e4390 R13: dffffc0000000000 R14: ffff88808f3e4390 R15: ffff88808f3e42f8 __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 br_nf_dev_queue_xmit+0x312/0x1590 include/linux/skbuff.h:4084 NF_HOOK include/linux/netfilter.h:305 [inline] br_nf_post_routing+0xa5f/0xea0 net/bridge/br_netfilter_hooks.c:844 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline] nf_hook_slow+0xc8/0x210 net/netfilter/core.c:512 nf_hook+0x23a/0x310 include/linux/netfilter.h:260 NF_HOOK include/linux/netfilter.h:303 [inline] br_forward_finish+0x7a/0xc0 net/bridge/br_forward.c:65 br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:1014 [inline] br_nf_forward_finish+0x8f4/0xc80 net/bridge/br_netfilter_hooks.c:560 NF_HOOK include/linux/netfilter.h:305 [inline] br_nf_forward_ip+0xed4/0x13f0 net/bridge/br_netfilter_hooks.c:630 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline] nf_hook_slow+0xc8/0x210 net/netfilter/core.c:512 nf_hook+0x23a/0x310 include/linux/netfilter.h:260 NF_HOOK include/linux/netfilter.h:303 [inline] __br_forward+0x39e/0x720 net/bridge/br_forward.c:109 br_flood+0x7af/0x840 net/bridge/br_forward.c:234 br_handle_frame_finish+0xf37/0x1370 net/bridge/br_input.c:162 br_nf_hook_thresh+0x306/0x390 net/bridge/br_netfilter_hooks.c:1014 br_nf_pre_routing_finish_ipv6+0x8ac/0xb30 net/bridge/br_netfilter_ipv6.c:187 NF_HOOK include/linux/netfilter.h:305 [inline] br_nf_pre_routing_ipv6+0x2ab/0x350 net/bridge/br_netfilter_ipv6.c:236 br_nf_pre_routing+0x6ca/0x1380 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+0x7d9/0xeb0 net/bridge/br_input.c:348 __netif_receive_skb_core+0x1a7d/0x3470 net/core/dev.c:4905 __netif_receive_skb_one_core net/core/dev.c:5002 [inline] __netif_receive_skb+0xc5/0x370 net/core/dev.c:5118 process_backlog+0x4d8/0x910 net/core/dev.c:5929 napi_poll net/core/dev.c:6352 [inline] net_rx_action+0x5ef/0xfd0 net/core/dev.c:6418 __do_softirq+0x333/0x7c4 arch/x86/include/asm/paravirt.h:778 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082 do_softirq+0xfd/0x190 kernel/softirq.c:337 __local_bh_enable_ip+0x194/0x240 kernel/softirq.c:189 local_bh_enable+0x1f/0x30 include/linux/bottom_half.h:32 rcu_read_unlock_bh include/linux/rcupdate.h:681 [inline] ip6_finish_output2+0x109f/0x13d0 net/ipv6/ip6_output.c:117 __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