rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P11618/1:b..l P3623/1:b..l P10919/1:b..l
	(detected by 1, t=10502 jiffies, g=76481, q=130 ncpus=2)
task:udevd           state:R  running task     stack:25944 pid:10919 ppid:3623   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5243 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6560
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6872
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:handle_mounts fs/namei.c:1527 [inline]
RIP: 0010:step_into+0xca0/0x1070 fs/namei.c:1836
Code: 24 20 48 8d b4 24 d0 00 00 00 49 be 00 00 00 00 00 fc ff df 4c 89 ef 48 8b 54 24 18 8b 4c 24 2c e8 d5 03 00 00 e9 6b f8 ff ff <48> 8d 8c 24 c0 00 00 00 80 e1 07 38 c1 0f 8c f9 f3 ff ff 48 8d bc
RSP: 0018:ffffc90003787940 EFLAGS: 00000202
RAX: 0000000000000001 RBX: dffffc0000000000 RCX: ffff8880534f9dc0
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffffc90003787c60
RBP: ffffc90003787a90 R08: ffffffff81f573c3 R09: ffffed1004e5ade5
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffffc90003787c60 R14: 1ffff920006f0f3c R15: 1ffff920006f0f40
 walk_component fs/namei.c:2004 [inline]
 link_path_walk+0x72c/0xee0 fs/namei.c:2325
 path_parentat fs/namei.c:2526 [inline]
 __filename_parentat+0x25e/0x6e0 fs/namei.c:2550
 filename_parentat fs/namei.c:2568 [inline]
 do_rmdir+0x127/0x590 fs/namei.c:4219
 __do_sys_rmdir fs/namei.c:4271 [inline]
 __se_sys_rmdir fs/namei.c:4269 [inline]
 __x64_sys_rmdir+0x45/0x50 fs/namei.c:4269
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f31e1917e07
RSP: 002b:00007ffce10763d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 00007ffce1076808 RCX: 00007f31e1917e07
RDX: 0000000000000000 RSI: 0000564c27c953c4 RDI: 00007ffce1076808
RBP: 00007ffce1077008 R08: 0000564c27c953c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffce1076408
R13: 0000564c27c97500 R14: 0000564c27c948a0 R15: 0000000000000000
 </TASK>
task:udevd           state:R  running task     stack:22760 pid:3623  ppid:1      flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5243 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6560
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6729
 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6753
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0x128/0x130 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __wake_up_common_lock kernel/sched/wait.c:140 [inline]
 __wake_up_sync_key+0x121/0x1c0 kernel/sched/wait.c:208
 sock_def_readable+0x15b/0x280 net/core/sock.c:3308
 __netlink_sendskb net/netlink/af_netlink.c:1258 [inline]
 netlink_sendskb+0x96/0x130 net/netlink/af_netlink.c:1264
 netlink_unicast+0x399/0x970 net/netlink/af_netlink.c:1352
 netlink_sendmsg+0xa26/0xd60 net/netlink/af_netlink.c:1859
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x5d3/0x9a0 net/socket.c:2519
 ___sys_sendmsg net/socket.c:2573 [inline]
 __sys_sendmsg+0x2a9/0x390 net/socket.c:2602
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f31e1924a4b
RSP: 002b:00007ffce10779e8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000564c27c749e0 RCX: 00007f31e1924a4b
RDX: 0000000000000000 RSI: 00007ffce10779f8 RDI: 0000000000000004
RBP: 0000564c27c97ac0 R08: 0000000000000001 R09: 0000000000000000
R10: 000000000000010f R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000000a7 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
task:rm              state:R  running task     stack:23880 pid:11618 ppid:11570  flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5243 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6560
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6729
 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6753
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 filemap_map_pages+0xffa/0x12c0 mm/filemap.c:3498
 do_fault_around mm/memory.c:4600 [inline]
 do_read_fault mm/memory.c:4626 [inline]
 do_fault mm/memory.c:4760 [inline]
 handle_pte_fault mm/memory.c:5031 [inline]
 __handle_mm_fault mm/memory.c:5173 [inline]
 handle_mm_fault+0x33e0/0x5340 mm/memory.c:5294
 do_user_addr_fault arch/x86/mm/fault.c:1340 [inline]
 handle_page_fault arch/x86/mm/fault.c:1431 [inline]
 exc_page_fault+0x26f/0x620 arch/x86/mm/fault.c:1487
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7f29fa2bc000
RSP: 002b:00007ffc8d5e5608 EFLAGS: 00010206
RAX: 00007f29fa2bc000 RBX: 00007f29fa5bb570 RCX: 00007ffc8d5e56b8
RDX: 00007ffc8d5e56b8 RSI: 00007ffc8d5e5698 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 000000000000000d
R10: 00007ffc8d5e52d0 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffc8d5e5698 R14: 00007ffc8d5e56b8 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10577 jiffies! g76481 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:26712 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5243 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6560
 schedule+0xbf/0x180 kernel/sched/core.c:6636
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 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 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 acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:567