rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5892/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=28305, q=457373 ncpus=2)
task:kworker/1:7     state:R  running task     stack:24952 pid:5892  tgid:5892  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x116f/0x5de0 kernel/sched/core.c:6767
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7090
 irqentry_exit+0x36/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5870
Code: 39 0c 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 52 07 ed 0e 0f 82 74 02 00 00 8b 35 ea 36 ed 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 29 39 0c 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc90004e7fae8 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3bfc00 RCX: 0000000098976749
RDX: 0000000000000000 RSI: ffffffff8dbbf003 RDI: ffffffff8bf4a2a0
RBP: 0000000000000002 R08: 20d35136f2fa4cfa R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 gc_worker+0x241/0x16e0 net/netfilter/nf_conntrack_core.c:1532
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>