rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4307/1:b..l (detected by 1, t=10502 jiffies, g=64505, q=110) task:kworker/u4:6 state:R running task stack:21880 pid: 4307 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04 RSP: 0018:ffffc900011efa40 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 5a03c25519aa6000 RDX: 0000000000000000 RSI: ffffffff8a2b2ea0 RDI: ffffffff8a79ec00 RBP: ffffc900011efb58 R08: dffffc0000000000 R09: 1ffffffff2037218 R10: dffffc0000000000 R11: fffffbfff2037219 R12: ffffffff8c31c720 R13: 1ffff9200023df54 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313 rcu_read_lock include/linux/rcupdate.h:740 [inline] batadv_nc_process_nc_paths+0xb2/0x350 net/batman-adv/network-coding.c:691 batadv_nc_worker+0x4e4/0x5c0 net/batman-adv/network-coding.c:739 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: rcu_preempt kthread starved for 8447 jiffies! g64505 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 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:27800 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 0 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:729