rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5960/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=41549, q=1090 ncpus=2)
task:kworker/1:7     state:R  running task     stack:22184 pid:5960  tgid:5960  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue: events_power_efficient gc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x116a/0x5de0 kernel/sched/core.c:6785
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7108
 irqentry_exit+0x36/0x90 kernel/entry/common.c:307
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__seqprop_spinlock_sequence include/linux/seqlock.h:227 [inline]
RIP: 0010:nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:333 [inline]
RIP: 0010:gc_worker+0x2d5/0x16e0 net/netfilter/nf_conntrack_core.c:1537
Code: 00 00 48 c7 c7 88 18 aa 90 e8 37 72 eb f7 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 15 18 0f f8 58 48 85 db 0f 85 d4 0f 00 00 <e8> 96 1c 0f f8 8b 1d 70 14 fd 06 41 89 dc 31 ff 41 83 e4 01 44 89
RSP: 0018:ffffc9000238fb58 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff89ad0f49
RDX: ffff88801e754880 RSI: ffffffff89ad0f58 RDI: 0000000000000007
RBP: ffffffff9b278e8c R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff888031e00000
R13: 0000000000040000 R14: dffffc0000000000 R15: 0000000000001770
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>