rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P9277
	(detected by 0, t=10502 jiffies, g=105509, q=14)
kworker/u4:6    R  running task    24792  9277      2 0x80004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 context_switch kernel/sched/core.c:3367 [inline]
 __schedule+0x937/0x1ff0 kernel/sched/core.c:4083
 __sched_text_start+0x8/0x8
 check_preemption_disabled lib/smp_processor_id.c:16 [inline]
 __this_cpu_preempt_check+0x28/0x190 lib/smp_processor_id.c:64
 set_irq_regs arch/x86/include/asm/irq_regs.h:27 [inline]
 smp_apic_timer_interrupt+0x1b6/0x600 arch/x86/kernel/apic/apic.c:1142
 retint_kernel+0x2b/0x2b
 preempt_schedule_notrace_thunk+0x16/0x2c arch/x86/entry/thunk_64.S:51
 preempt_schedule_notrace kernel/sched/core.c:4312 [inline]
 preempt_schedule_notrace+0x99/0x120 kernel/sched/core.c:4283
 preempt_schedule_notrace_thunk+0x16/0x2c arch/x86/entry/thunk_64.S:51
 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
 rcu_dynticks_curr_cpu_in_eqs+0x4f/0xb0 kernel/rcu/tree.c:302
 rcu_is_watching+0x1e/0x20 kernel/rcu/tree.c:930
 rcu_read_lock include/linux/rcupdate.h:602 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:407 [inline]
 batadv_nc_worker+0x4c3/0x760 net/batman-adv/network-coding.c:718
 process_one_work+0x965/0x16a0 kernel/workqueue.c:2268
 lock_release+0x800/0x800 kernel/locking/lockdep.c:4689
 pwq_dec_nr_in_flight+0x310/0x310 kernel/workqueue.c:1198
 rwlock_bug.part.0+0x90/0x90 include/linux/sched.h:1329
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:110 [inline]
 test_ti_thread_flag include/linux/thread_info.h:84 [inline]
 need_resched include/linux/sched.h:1827 [inline]
 schedule+0xe7/0x2a0 kernel/sched/core.c:4160
 worker_thread+0x96/0xe20 kernel/workqueue.c:2414
 process_one_work+0x16a0/0x16a0 kernel/workqueue.c:2273
 kthread+0x388/0x470 kernel/kthread.c:268
 kthread_mod_delayed_work+0x1a0/0x1a0 kernel/kthread.c:1090
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
rcu: rcu_preempt kthread starved for 10497 jiffies! g105509 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    28848    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3367 [inline]
 __schedule+0x937/0x1ff0 kernel/sched/core.c:4083
 __sched_text_start+0x8/0x8
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:117 [inline]
 _raw_spin_lock_irqsave+0x94/0xbf kernel/locking/spinlock.c:159
 check_preemption_disabled lib/smp_processor_id.c:52 [inline]
 debug_smp_processor_id+0x2f/0x185 lib/smp_processor_id.c:57
 schedule+0xd0/0x2a0 kernel/sched/core.c:4158
 schedule_timeout+0x35c/0x850 kernel/time/timer.c:1898
 usleep_range+0x160/0x160 kernel/time/timer.c:2093
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
 _raw_spin_unlock_irqrestore+0x62/0xe0 kernel/locking/spinlock.c:191
 __next_timer_interrupt+0x190/0x190 kernel/time/timer.c:1512
 prepare_to_swait_exclusive+0x110/0x110 kernel/sched/swait.c:98
 rcu_gp_fqs_loop kernel/rcu/tree.c:1674 [inline]
 rcu_gp_kthread+0x9bf/0x1960 kernel/rcu/tree.c:1836
 rcu_barrier+0x4b0/0x4b0 arch/x86/include/asm/paravirt.h:764
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
 _raw_spin_unlock_irqrestore+0x62/0xe0 kernel/locking/spinlock.c:191
 __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline]
 lockdep_hardirqs_on+0x463/0x620 kernel/locking/lockdep.c:3702
 __kthread_parkme+0x13f/0x1e0 kernel/kthread.c:212
 rcu_barrier+0x4b0/0x4b0 arch/x86/include/asm/paravirt.h:764
 kthread+0x388/0x470 kernel/kthread.c:268
 kthread_mod_delayed_work+0x1a0/0x1a0 kernel/kthread.c:1090
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352