rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3636/1:b..l
	(detected by 0, t=10502 jiffies, g=12601, q=18 ncpus=2)
task:kworker/u4:6    state:R  running task     stack:20960 pid:3636  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:lock_acquire+0x10d/0x5a0 kernel/locking/lockdep.c:5635
Code: 00 00 00 e8 45 ae 77 00 48 0f a3 1d 35 23 09 0d 73 0d e8 36 e4 08 00 84 c0 0f 84 b9 02 00 00 48 c7 c0 e4 be 73 8e 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 dd 02 00 00 83 3d c3 57 09 0d 00 0f 84
RSP: 0018:ffffc9000421fa80 EFLAGS: 00000a03
RAX: 1ffffffff1ce77dc RBX: 0000000000000001 RCX: ffffffff816a66eb
RDX: 0000000000000000 RSI: ffffffff8b3d4640 RDI: ffffffff8b3d4600
RBP: ffffc9000421fbe0 R08: dffffc0000000000 R09: fffffbfff1ce7146
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000843f58
R13: dffffc0000000000 R14: 0000000000000000 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0xe8/0x610 net/batman-adv/network-coding.c:719
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10500 jiffies! g12601 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=6539
rcu: rcu_preempt kthread starved for 10501 jiffies! g12601 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:26144 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </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 acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:572