rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P2557/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=51633, q=391 ncpus=2)
task:kworker/u8:8    state:R  running task     stack:23296 pid:2557  tgid:2557  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_mcast_mla_update
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:rcu_preempt_read_exit kernel/rcu/tree_plugin.h:394 [inline]
RIP: 0010:__rcu_read_unlock+0x3d/0x580 kernel/rcu/tree_plugin.h:433
Code: 53 48 8d bd 44 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 <84> d2 0f 85 42 02 00 00 65 4c 8b 25 f3 67 92 7e 49 8d bc 24 44 04
RSP: 0018:ffffc9000946faf8 EFLAGS: 00000202
RAX: 0000000000000007 RBX: 0000000000000001 RCX: ffffc9000946fab0
RDX: 0000000000000000 RSI: ffffffff8b4cc7c0 RDI: ffff88802a77de44
RBP: ffff88802a77da00 R08: 0000000000000000 R09: fffffbfff2025e9b
R10: ffffffff9012f4df R11: 0000000000000000 R12: ffff88802d4f8000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001
 rcu_read_unlock include/linux/rcupdate.h:871 [inline]
 batadv_mcast_mla_softif_get_ipv4 net/batman-adv/multicast.c:415 [inline]
 batadv_mcast_mla_softif_get net/batman-adv/multicast.c:532 [inline]
 __batadv_mcast_mla_update net/batman-adv/multicast.c:912 [inline]
 batadv_mcast_mla_update+0x1e47/0x3200 net/batman-adv/multicast.c:949
 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231
 process_scheduled_works kernel/workqueue.c:3312 [inline]
 worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390
 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 10364 jiffies! g51633 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:27200 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