rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3678/1:b..l
	(detected by 0, t=10502 jiffies, g=32089, q=159 ncpus=2)
task:kworker/u4:8    state:R  running task     stack:24728 pid:3678  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:rcu_is_watching+0x6c/0xb0 kernel/rcu/tree.c:723
Code: c3 a8 56 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 1e 8b 03 65 ff 0d 25 23 8f 7e 74 0c 83 e0 04 c1 e8 02 5b <41> 5e 41 5f c3 e8 e2 46 8d ff eb ed 89 d9 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffffc90004757be0 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffff88807c0d5940
RDX: ffff88807c0d5940 RSI: ffffffff8b3d4740 RDI: ffffffff8b3d4700
RBP: 0000000000000000 R08: ffffffff8a5c103a R09: fffffbfff2093845
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888021c60c80
R13: 000000000000020b R14: ffffffff8cb15868 R15: dffffc0000000000
 rcu_read_unlock include/linux/rcupdate.h:820 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
 batadv_nc_worker+0x203/0x610 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 starved for 10397 jiffies! g32089 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:26712 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