rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7306/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=216985, q=3966 ncpus=2)
task:kworker/1:9     state:R  running task     stack:20776 pid:7306  tgid:7306  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x17b4/0x5680 kernel/sched/core.c:7188
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7512
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
 irqentry_exit+0x14f/0x730 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872
Code: ff ff ff e8 e1 94 06 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 cb 5f 97 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d d8 5d 92
RSP: 0018:ffffc9000201f940 EFLAGS: 00000282
RAX: 9d8be3ca05015800 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 000000008f476d1a RSI: ffffffff8e218a1b RDI: ffffffff8c28ac60
RBP: ffffffff89cb924d R08: ffffffff89cb924d R09: ffffffff8e95cd60
R10: dffffc0000000000 R11: fffffbfff20614ff R12: 0000000000000002
R13: ffffffff8e95cd60 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 rcu_read_lock include/linux/rcupdate.h:838 [inline]
 gc_worker+0x281/0x1290 net/netfilter/nf_conntrack_core.c:1543
 process_one_work kernel/workqueue.c:3302 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>