rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4923/1:b..l
	(detected by 0, t=10502 jiffies, g=40985, q=3639)
task:kworker/1:16    state:R  running task     stack:22328 pid: 4923 ppid:     2 flags:0x00004000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777
 irqentry_exit+0x53/0x80 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:seqcount_lockdep_reader_access+0x1dc/0x220 include/linux/seqlock.h:106
Code: f8 4d 85 ed 75 16 e8 93 42 f0 f8 eb 15 e8 8c 42 f0 f8 e8 87 cd a3 01 4d 85 ed 74 ea e8 7d 42 f0 f8 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00
RSP: 0018:ffffc9000157fa40 EFLAGS: 00000293
RAX: ffffffff88903163 RBX: 0000000000000000 RCX: ffff8880224d8000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000157faf0 R08: ffffffff88903139 R09: fffffbfff20ec634
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 0000000000000200 R14: 0000000000000046 R15: 1ffff920002aff48
 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:338 [inline]
 gc_worker+0x30f/0x14b0 net/netfilter/nf_conntrack_core.c:1472
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>