rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=c044/1/0x4000000000000000 softirq=34884/34884 fqs=0
rcu: 	(detected by 1, t=10505 jiffies, g=30669, q=175 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 10508 Comm: syz.4.1377 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__lock_acquire+0xab9/0xd20
Code: 8d e8 4b cd e5 ff 90 0f 0b 90 90 90 31 c0 48 8b 3c 24 48 83 78 40 00 0f 84 6a 01 00 00 4c 89 f6 89 ea 4c 89 f9 e8 17 38 00 00 <85> c0 0f 84 e4 01 00 00 41 f6 46 22 10 75 2e 48 8b 1c 24 4c 89 bb
RSP: 0018:ffffc90000007750 EFLAGS: 00000086
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 7faf0308d49dce00
RDX: 0000000000000000 RSI: ffff8880328c4530 RDI: ffff8880328c3a00
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81ad9ddb
R10: dffffc0000000000 R11: ffffed1009604f59 R12: 0000000000000069
R13: ffff8880328c4530 R14: ffff8880328c4530 R15: 3ab6d40026a7fe15
FS:  00007f64a4a1b6c0(0000) GS:ffff8880b83e0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f64a49d9d58 CR3: 000000003765c000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 lock_acquire+0x120/0x360
 _raw_spin_lock_irqsave+0xa7/0xf0
 hrtimer_try_to_cancel+0x22b/0x420
 hrtimer_cancel+0x3b/0x50
 cpu_clock_event_stop+0xd9/0x130
 __perf_event_overflow+0x580/0xe40
 perf_swevent_hrtimer+0x3b8/0x500
 __hrtimer_run_queues+0x4e0/0xc60
 hrtimer_interrupt+0x45b/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:finish_task_switch+0x26b/0x950
Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 0f 69 f5 09 e8 ca 4f 36 00 fb 4c 8b 65 c0 <49> 8d bc 24 58 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc9000986fb38 EFLAGS: 00000282
RAX: 7faf0308d49dce00 RBX: 0000000000000000 RCX: 7faf0308d49dce00
RDX: 0000000000000000 RSI: ffffffff8dbc0fba RDI: ffffffff8c038200
RBP: ffffc9000986fb90 R08: ffffffff8fc43c37 R09: 1ffffffff1f88786
R10: dffffc0000000000 R11: fffffbfff1f88787 R12: ffff8880328c3a00
R13: dffffc0000000000 R14: ffff8880328c1d00 R15: ffff88804b03abd8
 __schedule+0x17a0/0x4cc0
 preempt_schedule_irq+0xb5/0x150
 irqentry_exit+0x6f/0x90
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:irqentry_exit_to_user_mode+0x51/0x120
Code: 07 85 c0 0f 85 c3 00 00 00 e8 cb 41 26 f6 65 4c 8b 34 25 08 00 c4 92 49 8b 3e f7 c7 1e 30 02 00 74 53 49 89 ff e8 af 40 26 f6 <4c> 89 f8 a8 18 74 08 e8 b3 19 01 00 4c 89 f8 a9 00 10 00 00 74 0b
RSP: 0000:ffffc9000986ff28 EFLAGS: 00000282
RAX: 7faf0308d49dce00 RBX: ffffc9000986ff48 RCX: 7faf0308d49dce00
RDX: 0000000000000000 RSI: ffffffff8dbc0fba RDI: ffffffff8c038200
RBP: 0000000000000000 R08: ffffffff8fc43c37 R09: 1ffffffff1f88786
R10: dffffc0000000000 R11: fffffbfff1f88787 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8880328c3a00 R15: 0000000000000008
 asm_sysvec_call_function_single+0x1a/0x20
RIP: 0033:0x7f64a3a5e806
Code: 53 48 83 ec 68 48 63 47 28 48 89 3c 24 48 8d 74 24 20 bf 01 00 00 00 89 44 24 10 48 c1 e0 07 48 01 d0 48 89 44 24 18 48 8b 18 <e8> 05 5b 12 00 85 c0 0f 85 5a 04 00 00 48 ba db 34 b6 d7 82 de 1b
RSP: 002b:00007f64a4a1b060 EFLAGS: 00000206
RAX: 00007f64a3cdd060 RBX: 00007f64a3c1ab78 RCX: 00007f64a3b8eba9
RDX: 00007f64a3c9ade0 RSI: 00007f64a4a1b080 RDI: 0000000000000001
RBP: 00007f64a3dd5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f64a3dd6038 R14: 00007ffc65d1dbc0 R15: 00007ffc65d1dca8
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10504 jiffies! g30669 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=14424
rcu: rcu_preempt kthread starved for 10505 jiffies! g30669 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26696 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x4bc/0x870
 ret_from_fork_asm+0x1a/0x30
 </TASK>
