rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6876/1:b..l
	(detected by 0, t=10503 jiffies, g=34641, q=25 ncpus=2)
task:modprobe        state:R  running task     stack:24160 pid:6876  ppid:4365   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:mas_validate_limits lib/maple_tree.c:-1 [inline]
RIP: 0010:mt_validate+0x2340/0x4c90 lib/maple_tree.c:7242
Code: 20 00 74 05 e8 31 7a cb f7 4d 8b 75 00 31 ff 4c 89 f6 e8 03 4f 7b f7 4d 85 f6 0f 85 33 01 00 00 e8 15 4b 7b f7 4c 8b 74 24 18 <e9> 00 fe ff ff e8 16 7f 64 f7 41 89 c6 31 ff 89 c6 e8 5a 4e 7b f7
RSP: 0018:ffffc9000458f5c0 EFLAGS: 00000293
RAX: ffffffff8a058b4b RBX: 000000000000000a RCX: ffff888024111dc0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000458f790 R08: ffff888024111dc0 R09: 0000000000000003
R10: 0000000000000003 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff88807b849a58 R14: 0000000000000001 R15: 000000000000000f
 validate_mm_mt+0xcd/0x420 mm/mmap.c:295
 validate_mm+0xcc/0x2b0 mm/mmap.c:332
 vma_expand+0x828/0x880 mm/mmap.c:604
 __mmap_region mm/mmap.c:2740 [inline]
 mmap_region+0xc24/0x1c70 mm/mmap.c:2916
 do_mmap+0x958/0xfd0 mm/mmap.c:1436
 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:520
 ksys_mmap_pgoff+0x516/0x6f0 mm/mmap.c:1482
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fed5db68242
RSP: 002b:00007ffdbbd85698 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007fed5db18000 RCX: 00007fed5db68242
RDX: 0000000000000001 RSI: 0000000000028000 RDI: 00007fed5db18000
RBP: 0000000000000812 R08: 0000000000000000 R09: 0000000000096000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffdbbd85720
R13: 00007fed5db440c0 R14: 00007ffdbbd85aa0 R15: 00000fffb77b0ad6
 </TASK>
rcu: rcu_preempt kthread starved for 10525 jiffies! g34641 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:27200 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 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 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:741
vkms_vblank_simulate: vblank timer overrun
hrtimer: interrupt took 516161332 ns