rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P11622/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=67821, q=869 ncpus=1)
task:kworker/0:8     state:R  running task     stack:23592 pid:11622 tgid:11622 ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x125c/0x6730 kernel/sched/core.c:7234
 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556
 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline]
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x205/0xa00 kernel/entry/common.c:167
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:228 [inline]
RIP: 0010:nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:343 [inline]
RIP: 0010:gc_worker+0x2bf/0x1a10 net/netfilter/nf_conntrack_core.c:1534
Code: 00 00 48 c7 c7 c8 3a 23 91 e8 9d 9e 09 f8 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 db 02 2e f8 58 48 85 db 0f 85 32 13 00 00 <e8> 2c 08 2e f8 8b 1d 06 e1 46 07 89 dd 31 ff 83 e5 01 89 ee e8 88
RSP: 0018:ffffc9000f50fb48 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff89dc6781
RDX: ffff8880307d2540 RSI: ffffffff89dc6790 RDI: ffff8880307d2540
RBP: ffff88814a000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000040000 R15: 000000000002c1c2
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>