rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6578/1:b..l
	(detected by 0, t=10502 jiffies, g=88493, q=203 ncpus=2)
task:kworker/u4:17   state:R  running task     stack:22928 pid:6578  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874
 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:rcu_read_unlock include/linux/rcupdate.h:820 [inline]
RIP: 0010:batadv_nc_process_nc_paths+0x27a/0x390 net/batman-adv/network-coding.c:699
Code: e1 8a f7 e8 f8 67 36 00 89 c5 31 ff 89 c6 e8 ed e4 8a f7 85 ed 74 15 e8 04 dc 74 f7 84 c0 74 18 e8 7b e1 8a f7 4c 8b 74 24 08 <eb> 65 e8 6f e1 8a f7 4c 8b 74 24 08 eb 59 e8 c3 67 36 00 89 c5 31
RSP: 0018:ffffc900037b7b70 EFLAGS: 00000293
RAX: ffffffff89f793d5 RBX: ffffffff89f79820 RCX: ffff8880266f1dc0
RDX: 0000000000000000 RSI: ffffffff8adf1180 RDI: ffffffff8adf1140
RBP: 0000000000000001 R08: dffffc0000000000 R09: 1ffffffff215f248
R10: dffffc0000000000 R11: fffffbfff215f249 R12: dffffc0000000000
R13: ffff88802d4657b0 R14: 0000000000000001 R15: ffff88802d464c80
 batadv_nc_worker+0x527/0x600 net/batman-adv/network-coding.c:735
 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1270 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 3562 jiffies! g88493 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=55889
rcu: rcu_preempt kthread starved for 3563 jiffies! g88493 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
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:27760 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
 schedule+0xb9/0x180 kernel/sched/core.c:6638
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x99/0x3b0 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 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:741