rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9205/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=99137, q=1058049 ncpus=2)
task:kworker/0:12    state:R  running task     stack:25000 pid:9205  tgid:9205  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x116a/0x5dd0 kernel/sched/core.c:6786
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7109
 irqentry_exit+0x36/0x90 kernel/entry/common.c:307
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x40 kernel/rcu/update.c:319
Code: 00 00 00 eb b6 e8 30 fa ff ff eb b6 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 8b 05 66 b1 22 05 85 c0 74 20 8b 05 60 e2 22 05 85 c0
RSP: 0018:ffffc9000d9f7b50 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff89ab730c
RDX: ffff88807e8c0000 RSI: ffffffff89ab78fe RDI: 0000000000000005
RBP: ffffffff9b26fa8c R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff888024800000
R13: 000000000000b11f R14: dffffc0000000000 R15: 0000000000001770
 rcu_read_unlock include/linux/rcupdate.h:869 [inline]
 gc_worker+0x973/0x16e0 net/netfilter/nf_conntrack_core.c:1620
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>