rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5944/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=34713, q=556582 ncpus=2)
task:kworker/1:4     state:R  running task     stack:21272 pid:5944  tgid:5944  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:seqcount_lockdep_reader_access+0x17e/0x1c0 include/linux/seqlock.h:75
Code: f8 4d 85 e4 75 16 e8 71 0e 13 f8 eb 15 e8 6a 0e 13 f8 e8 f5 b8 cd 01 4d 85 e4 74 ea e8 5b 0e 13 f8 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 66 43 c7 44 3e 09 00 00 43 c6 44 3e 0b 00
RSP: 0018:ffffc9000b1f7860 EFLAGS: 00000293
RAX: ffffffff89ac9f35 RBX: 0000000000000000 RCX: ffff88802f83bc00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000b1f7910 R08: ffffffff8fa3a837 R09: 1ffffffff1f47506
R10: dffffc0000000000 R11: fffffbfff1f47507 R12: 0000000000000200
R13: ffff888024925018 R14: 1ffff9200163ef0c R15: dffffc0000000000
 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:342 [inline]
 gc_worker+0x308/0x1380 net/netfilter/nf_conntrack_core.c:1548
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>