rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4381/1:b..l
	(detected by 1, t=10503 jiffies, g=10981, q=143 ncpus=2)
task:kworker/u4:8    state:R  running task     stack:20432 pid:4381  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__preempt_count_add kernel/rcu/tree.c:717 [inline]
RIP: 0010:rcu_is_watching+0x2/0xa0 kernel/rcu/tree.c:720
Code: eb 99 e8 91 bd ac 08 48 c7 c7 a0 17 b3 8c 4c 89 f6 e8 c2 a3 c3 02 e9 53 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 41 57 <41> 56 53 65 ff 05 bc 5a 97 7e e8 0f d2 ac 08 89 c3 83 f8 08 73 60
RSP: 0018:ffffc90004a6fbd0 EFLAGS: 00000202
RAX: ffffffff89e1badf RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff8880286c8000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffff88805a0cc8e8 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: dffffc0000000000
R13: ffffffff89e1baae R14: ffff88805a0acc80 R15: 000000000000011d
 rcu_read_lock include/linux/rcupdate.h:792 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0x108/0x600 net/batman-adv/network-coding.c:719
 process_one_work+0x898/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10496 jiffies! g10981 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=6770
rcu: rcu_preempt kthread starved for 10499 jiffies! g10981 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:26880 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 0 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:741