rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6949/1:b..l
	(detected by 1, t=10503 jiffies, g=23353, q=417)
task:kworker/0:16    state:R  running task     stack:25360 pid: 6949 ppid:     2 flags:0x00004000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
 irqentry_exit+0x63/0x70 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+0x196/0x1d0 include/linux/seqlock.h:106
Code: f9 4d 85 e4 75 16 e8 49 6d 54 f9 eb 15 e8 42 6d 54 f9 e8 7d 9e 98 01 4d 85 e4 74 ea e8 33 6d 54 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: 0018:ffffc9000359fa20 EFLAGS: 00000293
RAX: ffffffff8824dbbd RBX: 0000000000000000 RCX: ffff888023960000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000359fad0 R08: ffffffff901d815f R09: 1ffffffff203b02b
R10: dffffc0000000000 R11: fffffbfff203b02c R12: 0000000000000200
R13: ffff888075f6b718 R14: 1ffff920006b3f44 R15: dffffc0000000000
 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:338 [inline]
 gc_worker+0x2e2/0x1390 net/netfilter/nf_conntrack_core.c:1472
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>