rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P8253/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=69941, q=254 ncpus=2)
task:kworker/u8:22   state:R  running task     stack:23560 pid:8253  tgid:8253  ppid:2      task_flags:0x4208160 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
 irqentry_exit+0x36/0x90 kernel/entry/common.c:197
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:396 [inline]
RIP: 0010:__rcu_read_unlock+0x3d/0x550 kernel/rcu/tree_plugin.h:435
Code: 53 48 8d bd 44 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 <84> d2 0f 85 4a 02 00 00 65 4c 8b 25 5b c6 34 12 49 8d bc 24 44 04
RSP: 0018:ffffc9000c0e7af8 EFLAGS: 00000202
RAX: 0000000000000007 RBX: 0000000000000001 RCX: ffffc9000c0e7aec
RDX: 0000000000000000 RSI: ffffffff8de2d0d8 RDI: ffff888068778444
RBP: ffff888068778000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
 rcu_read_unlock include/linux/rcupdate.h:873 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
 batadv_nc_worker+0x89f/0x1030 net/batman-adv/network-coding.c:719
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:463
 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>