rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P964/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=42641, q=495 ncpus=2)
task:kworker/u8:5    state:R  running task     stack:23440 pid:964   tgid:964   ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0xe37/0x5490 kernel/sched/core.c:6529
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6851
 irqentry_exit+0x36/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x0/0x560 kernel/locking/lockdep.c:5727
Code: 24 04 e8 53 c3 80 00 8b 74 24 04 e9 1f ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 b8 00 00 00 00 00 fc ff df 41 57 4d 89 cf 41 56 49
RSP: 0018:ffffc90003ec7b80 EFLAGS: 00000246
RAX: ffffffff8ada93c4 RBX: ffff88807d170cd8 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8ddb9fe0
RBP: 000000000000019b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000400 R11: 0000000000000000 R12: 0000000000000001
R13: 000000000003db0c R14: 0000000000000000 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 rcu_read_lock include/linux/rcupdate.h:838 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0x16a/0x1060 net/batman-adv/network-coding.c:719
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xed0 kernel/workqueue.c:3389
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: rcu_preempt kthread starved for 10030 jiffies! g42641 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:27680 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0xe37/0x5490 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6621
 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581
 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2034
 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2236
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </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:48 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:111
sched: RT throttling activated