rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4679/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=50209, q=269 ncpus=2)
task:udevd           state:R  running task     stack:21632 pid:4679  tgid:4679  ppid:1      flags:0x00000002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851
 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:seqcount_lockdep_reader_access+0x1d6/0x220 include/linux/seqlock.h:75
Code: 62 e8 ce d5 79 ff 4d 85 f6 48 bb 00 00 00 00 00 fc ff df 75 07 e8 ba d5 79 ff eb 06 e8 b3 d5 79 ff fb 48 c7 04 24 0e 36 e0 45 <4a> c7 04 23 00 00 00 00 66 42 c7 44 23 09 00 00 42 c6 44 23 0b 00
RSP: 0018:ffffc90003137740 EFLAGS: 00000293
RAX: ffffffff8219b6ad RBX: dffffc0000000000 RCX: ffff88807c9b1e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900031377f0 R08: ffffffff8219b688 R09: 1ffffffff27f4d0f
R10: dffffc0000000000 R11: fffffbfff27f4d10 R12: 1ffff92000626ee8
R13: ffffc90003137760 R14: 0000000000000200 R15: 0000000000000046
 read_seqbegin include/linux/seqlock.h:772 [inline]
 read_seqbegin_or_lock include/linux/seqlock.h:1076 [inline]
 prepend_path+0xe1/0xbe0 fs/d_path.c:166
 d_absolute_path+0x179/0x310 fs/d_path.c:234
 tomoyo_get_absolute_path security/tomoyo/realpath.c:101 [inline]
 tomoyo_realpath_from_path+0x2b4/0x5e0 security/tomoyo/realpath.c:271
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x2b7/0x740 security/tomoyo/file.c:822
 security_inode_getattr+0xd8/0x130 security/security.c:2269
 vfs_getattr+0x45/0x430 fs/stat.c:204
 vfs_fstat fs/stat.c:229 [inline]
 vfs_fstatat+0xe4/0x190 fs/stat.c:338
 __do_sys_newfstatat fs/stat.c:505 [inline]
 __se_sys_newfstatat fs/stat.c:499 [inline]
 __x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:499
 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: 0033:0x7f8980b165f4
RSP: 002b:00007ffd0ac1de18 EFLAGS: 00000202 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 000055ba56055420 RCX: 00007f8980b165f4
RDX: 00007ffd0ac1de30 RSI: 00007f8980bb3130 RDI: 000000000000000e
RBP: 000055ba560185b0 R08: 0000000000090800 R09: 000055ba55fe9560
R10: 0000000000001000 R11: 0000000000000202 R12: 00007ffd0ac1de30
R13: 00000000000000fe R14: 000055ba275831c4 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10526 jiffies! g50209 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:24560 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/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+0x21/0x30 drivers/acpi/processor_idle.c:111