rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P965/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=16133, q=778 ncpus=2)
task:kworker/1:2     state:R  running task     stack:23864 pid:965   ppid:2      flags:0x00004000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009
 irqentry_exit+0x67/0x70 kernel/entry/common.c:438
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lock_acquire+0x1f2/0x410 kernel/locking/lockdep.c:5758
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 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:ffffc900042ef940 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 2536c94c543e0e00
RDX: 0000000000000000 RSI: ffffffff8aaace20 RDI: ffffffff8afc71c0
RBP: ffffc900042efa48 R08: dffffc0000000000 R09: 1ffffffff21b4ca0
R10: dffffc0000000000 R11: fffffbfff21b4ca1 R12: 1ffff9200085df34
R13: ffffffff8cd2fe20 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 rcu_read_lock include/linux/rcupdate.h:786 [inline]
 gc_worker+0x28d/0x14b0 net/netfilter/nf_conntrack_core.c:1502
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>