rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=116/1/0x4000000000000004 softirq=9549/9550 fqs=33 (t=10501 jiffies g=9205 q=54) rcu: rcu_preempt kthread starved for 10436 jiffies! g9205 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt I29520 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 0 CPU: 0 PID: 3021 Comm: kworker/0:2 Not tainted 5.3.0-rc8+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events iterate_cleanup_work 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: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:__sanitizer_cov_trace_pc+0x0/0x50 kernel/kcov.c:95 Code: 89 25 24 4d 19 09 41 bc f4 ff ff ff e8 9d 9f e9 ff 48 c7 05 0e 4d 19 09 00 00 00 00 e9 77 e9 ff ff 90 90 90 90 90 90 90 90 90 <55> 48 89 e5 65 48 8b 04 25 40 fe 01 00 65 8b 15 f4 88 8f 7e 81 e2 RSP: 0018:ffff8880ae808af0 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000301 RBX: ffff8880a1989978 RCX: ffffffff85c67051 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff8880ae808b48 R08: ffff88809f8fc180 R09: 0000000000000000 R10: fffffbfff134afaf R11: ffff88809f8fc180 R12: dffffc0000000000 R13: ffff8880a1989680 R14: 0000000000000001 R15: 0000000000000000 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 br_nf_dev_queue_xmit+0x34e/0x1470 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+0x6fb/0xd80 net/bridge/br_netfilter_ipv6.c:206 NF_HOOK include/linux/netfilter.h:305 [inline] br_nf_pre_routing_ipv6+0x456/0x832 net/bridge/br_netfilter_ipv6.c:236 br_nf_pre_routing+0x1743/0x2355 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+0x806/0x133e net/bridge/br_input.c:348 __netif_receive_skb_core+0xfc1/0x3060 net/core/dev.c:4905 __netif_receive_skb_one_core+0xa8/0x1a0 net/core/dev.c:5002 __netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5118 process_backlog+0x206/0x750 net/core/dev.c:5929 napi_poll net/core/dev.c:6352 [inline] net_rx_action+0x4d6/0x1030 net/core/dev.c:6418 __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 RIP: 0010:should_resched arch/x86/include/asm/preempt.h:102 [inline] RIP: 0010:__local_bh_enable_ip+0x18e/0x270 kernel/softirq.c:196 Code: 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 df 00 00 00 48 83 3d 7f 59 8d 07 00 0f 84 8f 00 00 00 fb 66 0f 1f 44 00 00 <65> 8b 05 13 63 bc 7e 85 c0 74 7f 5b 41 5c 41 5d 5d c3 80 3d c6 0b RSP: 0018:ffff88809f9c7bb0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11a5e8c RBX: 0000000000000200 RCX: 1ffffffff134b5ee RDX: dffffc0000000000 RSI: ffffffff8177f15e RDI: ffffffff81459aba RBP: ffff88809f9c7bc8 R08: ffff88809f8fc180 R09: fffffbfff118b838 R10: fffffbfff118b837 R11: ffffffff88c5c1bb R12: ffffffff85d21651 R13: ffffffff88c5c1b8 R14: 0000000000000001 R15: dffffc0000000000 local_bh_enable include/linux/bottom_half.h:32 [inline] get_next_corpse net/netfilter/nf_conntrack_core.c:2014 [inline] nf_ct_iterate_cleanup+0x217/0x4e0 net/netfilter/nf_conntrack_core.c:2037 nf_ct_iterate_cleanup_net net/netfilter/nf_conntrack_core.c:2122 [inline] nf_ct_iterate_cleanup_net+0x133/0x190 net/netfilter/nf_conntrack_core.c:2107 iterate_cleanup_work+0x4a/0xd7 net/netfilter/nf_nat_masquerade.c:216 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