rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P1108/1:b..l
	(detected by 1, t=10502 jiffies, g=28909, q=1607)
task:kworker/0:2     state:R  running task     stack:24080 pid: 1108 ppid:     2 flags:0x00004000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 kernel/entry/common.c:435
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:seqcount_lockdep_reader_access+0x196/0x1d0 include/linux/seqlock.h:106
Code: f9 4d 85 e4 75 16 e8 49 2e 50 f9 eb 15 e8 42 2e 50 f9 e8 ad 21 99 01 4d 85 e4 74 ea e8 33 2e 50 f9 fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 3e 00 00 00 00 43 c7 44 3e 08 00 00 00 00 65 48 8b 04 25
RSP: 0000:ffffc900044a7a20 EFLAGS: 00000293
RAX: ffffffff8828f52d RBX: 0000000000000000 RCX: ffff888021f75940
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900044a7ad0 R08: ffffffff9101515f R09: 1ffffffff2202a2b
R10: dffffc0000000000 R11: fffffbfff2202a2c R12: 0000000000000200
R13: ffff88807747c480 R14: 1ffff92000894f44 R15: dffffc0000000000
 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:343 [inline]
 gc_worker+0x2e5/0x13d0 net/netfilter/nf_conntrack_core.c:1486
 process_one_work+0x867/0xff0 kernel/workqueue.c:2310
 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>