rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5524/1:b..l P6519/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=17209, q=384 ncpus=2)
task:sed             state:R  running task     stack:23680 pid:6519  tgid:6519  ppid:6518   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5408 [inline]
 __schedule+0x17e8/0x4a20 kernel/sched/core.c:6745
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7067
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:mt_slot lib/maple_tree.c:788 [inline]
RIP: 0010:mas_slot lib/maple_tree.c:821 [inline]
RIP: 0010:mas_validate_limits lib/maple_tree.c:7508 [inline]
RIP: 0010:mt_validate+0x17e8/0x4aa0 lib/maple_tree.c:7593
Code: 1e 94 7f f6 4c 8b bc 24 40 01 00 00 44 89 74 24 08 41 0f b6 c6 48 8b 4c 24 38 48 8d 1c c1 48 89 d8 48 c1 e8 03 42 80 3c 28 00 <74> 08 48 89 df e8 ee 93 7f f6 4c 8b 33 e8 16 47 0a 00 89 c3 31 ff
RSP: 0018:ffffc90004a07700 EFLAGS: 00000246
RAX: 1ffff11003e7184d RBX: ffff88801f38c268 RCX: ffff88801f38c250
RDX: ffff888020ad0000 RSI: 000000000000000a RDI: 0000000000000003
RBP: ffffc90004a078f0 R08: ffffffff8b7c5730 R09: ffffffff8b7c5564
R10: 0000000000000003 R11: ffff888020ad0000 R12: 0000000000000002
R13: dffffc0000000000 R14: 0000000000000003 R15: ffff8880306eafc0
 validate_mm+0xe7/0x530 mm/mmap.c:288
 mmap_region+0x1a61/0x2090 mm/mmap.c:3000
 do_mmap+0x8ad/0xfa0 mm/mmap.c:1397
 vm_mmap_pgoff+0x1dd/0x3d0 mm/util.c:573
 ksys_mmap_pgoff+0x4f1/0x720 mm/mmap.c:1443
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8e72489b74
RSP: 002b:00007ffde9566e68 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007ffde9566f18 RCX: 00007f8e72489b74
RDX: 0000000000000003 RSI: 0000000000002000 RDI: 00007f8e721b9000
RBP: 00007ffde9567200 R08: 0000000000000003 R09: 0000000000052000
R10: 0000000000000812 R11: 0000000000000246 R12: 00007f8e72467570
R13: 00007ffde9567288 R14: 0000000000052120 R15: 0000000000000000
 </TASK>
task:kworker/u8:11   state:R  running task     stack:24336 pid:5524  tgid:5524  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5408 [inline]
 __schedule+0x17e8/0x4a20 kernel/sched/core.c:6745
 preempt_schedule_notrace+0x100/0x140 kernel/sched/core.c:7017
 preempt_schedule_notrace_thunk+0x1a/0x30 arch/x86/entry/thunk.S:13
 rcu_is_watching+0x7e/0xb0 kernel/rcu/tree.c:725
 rcu_read_lock include/linux/rcupdate.h:782 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0x10b/0x610 net/batman-adv/network-coding.c:719
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xa2e/0x1830 kernel/workqueue.c:3312
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3393
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/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 10501 jiffies! g17209 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:25560 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5408 [inline]
 __schedule+0x17e8/0x4a20 kernel/sched/core.c:6745
 __schedule_loop kernel/sched/core.c:6822 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6837
 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2000
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2202
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/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:86 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:112