rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5911/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=33949, q=948437 ncpus=2)
task:kworker/1:5     state:R  running task     stack:21480 pid:5911  tgid:5911  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5254 [inline]
 __schedule+0x17c4/0x4d60 kernel/sched/core.c:6862
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7189
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:lock_acquire+0x5f/0x360 kernel/locking/lockdep.c:5831
Code: 89 44 24 58 0f 1f 44 00 00 65 8b 05 6f 6c d2 10 83 f8 08 0f 83 b8 01 00 00 89 c0 48 0f a3 05 98 f8 df 0d 73 16 e8 e1 03 09 00 <84> c0 75 0d f6 05 0a 00 ca 0d 01 0f 84 d7 01 00 00 83 3d 99 28 e0
RSP: 0018:ffffc9000455f860 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 97e548d92ce4ab00
RDX: 0000000000000000 RSI: ffffffff8bbf1b40 RDI: ffffffff8bbf1b00
RBP: ffffffff89758474 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1efad8f R12: 0000000000000002
R13: ffffffff8df3d5a0 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 gc_worker+0x285/0x1380 net/netfilter/nf_conntrack_core.c:1546
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>