rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P32/1:b..l
	(detected by 0, t=10502 jiffies, g=23105, q=145 ncpus=2)
task:kworker/u4:2    state:R  running task     stack:22560 pid:32    ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:409 [inline]
RIP: 0010:batadv_nc_worker+0x170/0x600 net/batman-adv/network-coding.c:719
Code: 36 4b 9f f7 c6 05 bd 7a 29 04 01 48 c7 c7 80 d1 ad 8b be 19 03 00 00 48 c7 c2 c0 d1 ad 8b e8 37 1d 82 f7 48 89 e8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 ef e8 21 78 ef f7 48 8b 6d 00 48 85 ed
RSP: 0018:ffffc90000a97be0 EFLAGS: 00000a02
RAX: 1ffff1100aeceb4f RBX: 0000000000000001 RCX: ffff88801aa80000
RDX: 0000000000000000 RSI: ffffffff8adefd00 RDI: ffffffff8adefcc0
RBP: ffff888057675a78 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: dffffc0000000000
R13: ffffffff89e1833e R14: ffff8880570ecc80 R15: 000000000000034f
 process_one_work+0x898/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1250 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 starved for 9613 jiffies! g23105 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:27840 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 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