rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (1 GPs behind) idle=836/1/0x4000000000000004 softirq=198271/198272 fqs=5237 (t=10500 jiffies g=322685 q=541) NMI backtrace for cpu 1 CPU: 1 PID: 30746 Comm: kworker/u4:5 Not tainted 5.3.0-rc7+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker 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: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:preempt_count arch/x86/include/asm/preempt.h:26 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:68 [inline] RIP: 0010:write_comp_data+0x9/0x70 kernel/kcov.c:123 Code: 12 00 00 8b 80 f4 12 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 5d c3 0f 1f 00 65 4c 8b 04 25 40 fe 01 00 <65> 8b 05 58 88 8f 7e a9 00 01 1f 00 75 51 41 8b 80 f0 12 00 00 83 RSP: 0018:ffff8880ae9096e0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: ffff8880790ebdf8 RCX: ffffffff85c7e4d9 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff8880ae9096e8 R08: ffff8880658ee040 R09: fffffbfff14e9755 R10: ffff8880658ee9c0 R11: ffff8880658ee040 R12: dffffc0000000000 R13: ffff8880790ebb00 R14: ffff8880790ebe98 R15: ffff8880790ebe90 __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+0x679/0xa20 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+0x16f1/0x3650 net/core/dev.c:3838 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902 br_send_bpdu_finish net/bridge/br_stp_bpdu.c:32 [inline] NF_HOOK include/linux/netfilter.h:305 [inline] br_send_bpdu.isra.0.constprop.0+0x5ce/0xa70 net/bridge/br_stp_bpdu.c:59 br_send_config_bpdu+0x68c/0x7a0 net/bridge/br_stp_bpdu.c:120 br_transmit_config.part.0+0x517/0x780 net/bridge/br_stp.c:203 br_transmit_config net/bridge/br_stp.c:364 [inline] br_config_bpdu_generation+0x1d2/0x230 net/bridge/br_stp.c:362 br_hello_timer_expired+0xab/0x190 net/bridge/br_stp_timer.c:37 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1322 expire_timers kernel/time/timer.c:1366 [inline] __run_timers kernel/time/timer.c:1685 [inline] __run_timers kernel/time/timer.c:1653 [inline] run_timer_softirq+0x697/0x17a0 kernel/time/timer.c:1698 __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:1133 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:batadv_nc_purge_paths+0x27e/0x370 net/batman-adv/network-coding.c:436 Code: fe ff ff e8 24 1d 4e fa 48 8b 7d b8 e8 eb ad 1c 00 48 8b 45 b0 83 45 c4 01 48 c1 e8 03 42 0f b6 04 28 84 c0 74 04 3c 03 7e 75 <48> 8b 45 c8 44 8b 7d c4 8b 58 10 44 89 fe 89 df e8 ed 1d 4e fa 44 RSP: 0018:ffff88809470fc60 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: ffff88809637da38 RCX: 0000000000000006 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff8880658ee8cc RBP: ffff88809470fcd0 R08: 1ffffffff14e9755 R09: fffffbfff14e9756 R10: fffffbfff14e9755 R11: ffffffff8a74baaf R12: 0000000000000000 R13: dffffc0000000000 R14: ffffffff87246190 R15: 0000000000000029 batadv_nc_worker+0x29c/0x760 net/batman-adv/network-coding.c:719 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