rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5556/1:b..l
	(detected by 1, t=10502 jiffies, g=25877, q=249)
task:kworker/u4:10   state:R  running task     stack:23128 pid: 5556 ppid:     2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6779
 irqentry_exit+0x53/0x80 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:740 [inline]
RIP: 0010:batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
RIP: 0010:batadv_nc_worker+0xcc/0x5b0 net/batman-adv/network-coding.c:723
Code: 74 08 4c 89 ff e8 54 cc ad f7 4a 8d 1c e5 00 00 00 00 49 03 1f e8 44 3c 4f f7 e8 8f 81 00 00 e8 1a 42 23 00 89 c5 31 ff 89 c6 <e8> 3f dd 63 f7 85 ed 74 10 e8 56 8a 4e f7 84 c0 74 0e e8 cd d9 63
RSP: 0018:ffffc9000311fbf8 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffff888060ec0380 RCX: ffff888027f68000
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff2131e19
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000070
R13: dffffc0000000000 R14: ffff888062fa0c80 R15: ffff88802b1b6840
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: rcu_preempt kthread starved for 8659 jiffies! g25877 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:27000 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375
 schedule+0x11b/0x1f0 kernel/sched/core.c:6458
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </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 acpi_safe_halt drivers/acpi/processor_idle.c:108 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562