rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=bf8c/1/0x4000000000000000 softirq=15325/15325 fqs=0
rcu: 	(detected by 0, t=10502 jiffies, g=7305, q=480 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5961 Comm: syz.0.13 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:do_raw_spin_lock+0x155/0x290
Code: 0f b1 0b 0f 85 dd 00 00 00 65 8b 1d 29 d7 02 11 48 b9 00 00 00 00 00 fc ff df 41 0f b6 04 0f 49 89 cf 84 c0 0f 85 0b 01 00 00 <41> 89 5d 00 43 80 3c 3e 00 74 08 4c 89 e7 e8 48 d3 85 00 48 8b 44
RSP: 0018:ffffc900001e07c0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000001 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc900001e0800
RBP: ffffc900001e0870 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200003c100 R12: ffff888136627a90
R13: ffff888136627a88 R14: 1ffff11026cc4f52 R15: dffffc0000000000
FS:  00007f516fe2f6c0(0000) GS:ffff8881a3c11000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f516fe2efc8 CR3: 000000011436e000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 _raw_spin_lock_irqsave+0xb3/0xf0
 hrtimer_try_to_cancel+0x22b/0x420
 hrtimer_cancel+0x3b/0x50
 cpu_clock_event_stop+0xd9/0x130
 __perf_event_overflow+0x580/0xe40
 perf_swevent_hrtimer+0x3c5/0x550
 __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:perf_trace_init+0x1a2/0x2d0
Code: 74 b8 03 00 84 c0 0f 85 a1 00 00 00 e8 a7 88 f6 ff 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 81 ae 5a 00 48 8b 1b <48> 81 fb 60 d7 19 8e 74 45 e8 80 88 f6 ff e9 d1 fe ff ff 44 89 e1
RSP: 0018:ffffc9000424fa78 EFLAGS: 00000246
RAX: 1ffffffff1f00274 RBX: ffffffff8f801300 RCX: ffff88801b321cc0
RDX: 0000000000000000 RSI: 000000000000105d RDI: 000000000000014a
RBP: 0000000000000002 R08: ffffffff8fa3b537 R09: 1ffffffff1f476a6
R10: dffffc0000000000 R11: fffffbfff1f476a7 R12: 000000000000105d
R13: 0000000000000000 R14: dffffc0000000000 R15: 000000000000014a
 perf_tp_event_init+0x8d/0x120
 perf_try_init_event+0x17f/0x870
 perf_event_alloc+0x133e/0x2be0
 __se_sys_perf_event_open+0x772/0x1d70
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f516ef8ec29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f516fe2f038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f516f1d5fa0 RCX: 00007f516ef8ec29
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000180
RBP: 00007f516f011e41 R08: 000000000000000a R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f516f1d6038 R14: 00007f516f1d5fa0 R15: 00007ffd57634888
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g7305 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=2233
rcu: rcu_preempt kthread starved for 10502 jiffies! g7305 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27432 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+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
