rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P17719/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=68429, q=869 ncpus=2)
task:kworker/1:6     state:R  running task     stack:27624 pid:17719 tgid:17719 ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238
 irqentry_exit+0x599/0x620 kernel/entry/common.c:239
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x2d7/0x3d0 kernel/locking/lockdep.c:5893
Code: 88 7a 11 00 00 00 00 eb b5 e8 55 85 0c 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 d5 42 7a 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 a5 83 6e ff cc 48 8d 3d 42 34 73
RSP: 0018:ffffc9000d0e7948 EFLAGS: 00000286
RAX: 898a7ae888b76500 RBX: 0000000000000202 RCX: 0000000000000046
RDX: 0000000000000002 RSI: ffffffff8e167611 RDI: ffffffff8c27be00
RBP: ffff88802f3b48a8 R08: ffffffff90119ab7 R09: 1ffffffff2023356
R10: dffffc0000000000 R11: fffffbfff2023357 R12: 0000000000000002
R13: 0000000000000002 R14: ffffffff8e75e520 R15: ffff88802f3b3d00
 rcu_lock_release include/linux/rcupdate.h:322 [inline]
 rcu_read_unlock include/linux/rcupdate.h:881 [inline]
 gc_worker+0xb4c/0x1290 net/netfilter/nf_conntrack_core.c:1617
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>