rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10500 ticks this GP) idle=04e/1/0x4000000000000002 softirq=20846/20846 fqs=0 (t=10500 jiffies g=29281 q=699) rcu: rcu_preempt kthread starved for 10500 jiffies! g29281 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt I29032 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3265 [inline] __schedule+0x76e/0x17a0 kernel/sched/core.c:3937 schedule+0xd9/0x260 kernel/sched/core.c:4004 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1893 rcu_gp_fqs_loop kernel/rcu/tree.c:1639 [inline] rcu_gp_kthread+0x9b2/0x18d0 kernel/rcu/tree.c:1799 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 0 CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.3.0-rc6-next-20190830 #75 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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_valid+0x23/0xa0 lib/list_debug.c:23 Code: 90 90 90 90 90 90 90 48 b8 00 00 00 00 00 fc ff df 55 48 89 e5 41 55 49 89 fd 48 8d 7a 08 41 54 49 89 d4 48 89 fa 48 83 ec 08 <48> c1 ea 03 80 3c 02 00 75 52 49 8b 54 24 08 48 39 f2 0f 85 5a 01 RSP: 0018:ffff8880a98ae980 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: dffffc0000000000 RBX: ffff888098a3b2f8 RCX: ffffffff85cb6ed1 RDX: ffff888098a3b398 RSI: ffff888098a3b390 RDI: ffff888098a3b398 RBP: ffff8880a98ae998 R08: ffff8880a989c240 R09: fffffbfff14ed341 R10: ffff8880a989cba8 R11: ffff8880a989c240 R12: ffff888098a3b390 R13: ffff888098a3b2f8 R14: ffff888098a3b398 R15: ffff888098a3b390 __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+0x66d/0xa20 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+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 br_nf_dev_queue_xmit+0x34e/0x14b0 net/bridge/br_netfilter_hooks.c:796 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] br_nf_post_routing+0x1502/0x1d30 net/bridge/br_netfilter_hooks.c:844 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline] nf_hook_slow+0xbc/0x1e0 net/netfilter/core.c:512 nf_hook include/linux/netfilter.h:260 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] br_forward_finish+0x215/0x400 net/bridge/br_forward.c:65 br_nf_hook_thresh+0x2e9/0x370 net/bridge/br_netfilter_hooks.c:1015 br_nf_forward_finish+0x66c/0xa90 net/bridge/br_netfilter_hooks.c:560 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] br_nf_forward_ip net/bridge/br_netfilter_hooks.c:630 [inline] br_nf_forward_ip+0xc74/0x21e0 net/bridge/br_netfilter_hooks.c:571 nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline] nf_hook_slow+0xbc/0x1e0 net/netfilter/core.c:512 nf_hook include/linux/netfilter.h:260 [inline] NF_HOOK include/linux/netfilter.h:303 [inline] __br_forward+0x393/0xb00 net/bridge/br_forward.c:109 deliver_clone+0x61/0xc0 net/bridge/br_forward.c:125 br_flood+0x325/0x3d0 net/bridge/br_forward.c:232 br_handle_frame_finish+0xb46/0x1670 net/bridge/br_input.c:162 br_nf_hook_thresh+0x2e9/0x370 net/bridge/br_netfilter_hooks.c:1015 br_nf_pre_routing_finish_ipv6+0x6fa/0xdb0 net/bridge/br_netfilter_ipv6.c:206 NF_HOOK include/linux/netfilter.h:305 [inline] br_nf_pre_routing_ipv6+0x456/0x840 net/bridge/br_netfilter_ipv6.c:236 br_nf_pre_routing+0x1743/0x2360 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+0x806/0x1340 net/bridge/br_input.c:348 __netif_receive_skb_core+0xfc1/0x3060 net/core/dev.c:4907 __netif_receive_skb_one_core+0xa8/0x1a0 net/core/dev.c:5004 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5120 process_backlog+0x206/0x750 net/core/dev.c:5951 napi_poll net/core/dev.c:6388 [inline] net_rx_action+0x50a/0x10d0 net/core/dev.c:6456 __do_softirq+0x262/0x98c kernel/softirq.c:292 run_ksoftirqd kernel/softirq.c:603 [inline] run_ksoftirqd+0x8e/0x110 kernel/softirq.c:595 smpboot_thread_fn+0x6a3/0xa40 kernel/smpboot.c:165 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352