rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5817/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=22249, q=336337 ncpus=2)
task:kworker/0:7     state:R  running task     stack:24856 pid:5817  tgid:5817  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1821/0x5740 kernel/sched/core.c:7189
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x14f/0x8b0 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:seqcount_lockdep_reader_access+0xed/0x100 include/linux/seqlock.h:76
Code: 00 75 11 e8 05 32 fc f7 4d 85 f6 75 16 e8 fb 31 fc f7 eb 15 e8 f4 31 fc f7 e8 6f e0 dd 01 4d 85 f6 74 ea e8 e5 31 fc f7 fb 5b <41> 5e e9 0c d5 e0 01 cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90
RSP: 0018:ffffc90004ebf970 EFLAGS: 00000293
RAX: ffffffff89c984cb RBX: 0000000000000001 RCX: ffff888027dcdd00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90004ebfad0 R08: ffffffff903034f7 R09: 1ffffffff206069e
R10: dffffc0000000000 R11: fffffbfff206069f R12: dffffc0000000000
R13: ffffffff9a93c8c0 R14: 0000000000000200 R15: 0000000000001936
 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:343 [inline]
 gc_worker+0x304/0x1290 net/netfilter/nf_conntrack_core.c:1552
 process_one_work kernel/workqueue.c:3314 [inline]
 process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
 kthread+0x389/0x470 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>