rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6976/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=54717, q=3713 ncpus=2)
task:kworker/0:12    state:R  running task     stack:24288 pid:6976  tgid:6976  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7190
 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
 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:75
Code: 00 75 11 e8 15 b6 3e f8 4d 85 f6 75 16 e8 0b b6 3e f8 eb 15 e8 04 b6 3e f8 e8 ff 50 d7 01 4d 85 f6 74 ea e8 f5 b5 3e f8 fb 5b <41> 5e e9 f7 00 8e f7 cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90
RSP: 0018:ffffc90004b97910 EFLAGS: 00000293
RAX: ffffffff8982400b RBX: 0000000000000001 RCX: ffff88802a243d00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90004b97a70 R08: ffffffff8f822177 R09: 1ffffffff1f0442e
R10: dffffc0000000000 R11: fffffbfff1f0442f R12: ffff8880b863a080
R13: ffff8880280b2618 R14: 0000000000000200 R15: 0000000000040000
 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:342 [inline]
 gc_worker+0x308/0x1380 net/netfilter/nf_conntrack_core.c:1548
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>