rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=6893, q=113)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294955133-4294944630), jiffies_till_next_fqs=1, root ->qsmask 0x0
kworker/1:8     R  running task    28712  2703      2 0x80004008
Workqueue: events iterate_cleanup_work
Call Trace:
 <IRQ>
 sched_show_task+0x40f/0x560 kernel/sched/core.c:5954
 print_other_cpu_stall kernel/rcu/tree_stall.h:410 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:538 [inline]
 rcu_pending kernel/rcu/tree.c:2827 [inline]
 rcu_sched_clock_irq+0x1861/0x1ad0 kernel/rcu/tree.c:2271
 update_process_times+0x12d/0x180 kernel/time/timer.c:1726
 tick_sched_handle kernel/time/tick-sched.c:167 [inline]
 tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310
 __run_hrtimer kernel/time/hrtimer.c:1517 [inline]
 __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1579
 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1641
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:__memcg_kmem_uncharge+0x24/0x1a0 mm/memcontrol.c:2909
Code: 1f 80 00 00 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 50 89 f3 49 89 fc 48 b8 00 00 00 00 00 fc ff df 4c 8d 77 38 4d 89 f5 <49> c1 ed 03 41 80 7c 05 00 00 74 08 4c 89 f7 e8 48 07 fb ff 4d 8b
RSP: 0018:ffffc900078a78a8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffff88809fcf2000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffea000255ddc0
RBP: ffffc900078a78d8 R08: 000000000003a728 R09: ffffed1012c55749
R10: ffffed1012c55749 R11: 0000000000000000 R12: ffffea000255ddc0
R13: ffffea000255ddf8 R14: ffffea000255ddf8 R15: ffff8880962aba38
 memcg_kmem_uncharge include/linux/memcontrol.h:1402 [inline]
 free_thread_stack+0x12e/0x590 kernel/fork.c:284
 release_task_stack kernel/fork.c:440 [inline]
 put_task_stack+0xa3/0x130 kernel/fork.c:451
 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256
 context_switch kernel/sched/core.c:3388 [inline]
 __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081
 preempt_schedule_irq+0xc1/0x140 kernel/sched/core.c:4338
 retint_kernel+0x1b/0x2b
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline]
RIP: 0010:lock_is_held_type+0x25c/0x2b0 kernel/locking/lockdep.c:4524
Code: 68 95 2a 89 48 c1 e8 03 42 80 3c 30 00 74 0c 48 c7 c7 68 95 2a 89 e8 33 50 57 00 48 83 3d c3 be ce 07 00 74 56 4c 89 e7 57 9d <0f> 1f 44 00 00 89 d8 48 83 c4 28 5b 41 5c 41 5d 41 5e 41 5f 5d c3
RSP: 0018:ffffc900078a7b30 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff12552ad RBX: 0000000000000000 RCX: ffffffff815c1e17
RDX: dffffc0000000000 RSI: ffff88809fcf28e0 RDI: 0000000000000286
RBP: ffffc900078a7b80 R08: ffff88809fcf2858 R09: fffffbfff140cf3c
R10: fffffbfff140cf3c R11: 0000000000000000 R12: 0000000000000286
R13: ffff88809fcf2894 R14: dffffc0000000000 R15: 1ffff11013f9e512
 lock_is_held include/linux/lockdep.h:361 [inline]
 ___might_sleep+0x84/0x5e0 kernel/sched/core.c:6765
 get_next_corpse net/netfilter/nf_conntrack_core.c:2013 [inline]
 nf_ct_iterate_cleanup+0x30d/0x390 net/netfilter/nf_conntrack_core.c:2035
 nf_ct_iterate_cleanup_net+0xf9/0x150 net/netfilter/nf_conntrack_core.c:2120
 iterate_cleanup_work+0x4f/0x100 net/netfilter/nf_nat_masquerade.c:216
 process_one_work+0x7ef/0x10d0 kernel/workqueue.c:2264
 worker_thread+0xc01/0x1630 kernel/workqueue.c:2410
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
rcu: rcu_preempt kthread starved for 10537 jiffies! g6893 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    28984    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3385 [inline]
 __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081
 schedule+0x181/0x210 kernel/sched/core.c:4155
 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline]
 rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352