rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=c1b4/1/0x4000000000000000 softirq=17036/17036 fqs=0
rcu: 	(detected by 0, t=10505 jiffies, g=9777, q=379 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6493 Comm: syz.0.153 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+0x2ad/0xd20
Code: 01 e8 89 f1 81 e1 ff 1f 00 00 ba 00 e0 ff ff 41 23 54 c7 20 09 ca 41 89 54 c7 20 4d 89 4c c7 08 49 89 5c c7 10 4c 8b 6c 24 68 <4d> 89 6c c7 18 65 8b 15 13 97 03 11 31 f6 85 d2 40 0f 95 c6 31 d2
RSP: 0000:ffffc900001e0750 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffff888136627a98 RCX: 0000000000000067
RDX: 00000000000c4067 RSI: 0000000000000067 RDI: ffff888022151cc0
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81ada78b
R10: dffffc0000000000 R11: ffffed1026cc4f51 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880221527b0
FS:  00007f56feb016c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31c18ff8 CR3: 00000001100b6000 CR4: 00000000000006f0
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+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:raw_spin_rq_unlock_irq+0x13/0x90
Code: cc e8 d1 15 e8 09 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 41 56 53 66 90 e8 74 ac ea 09 e8 7f 29 35 00 fb 5b <41> 5e 41 5f e9 d4 fa ea 09 cc f3 0f 1e fa 49 be 00 00 00 00 00 fc
RSP: 0000:ffffc900065e7cc8 EFLAGS: 00000282
RAX: 9781d23e0cace200 RBX: ffff888136639f80 RCX: 9781d23e0cace200
RDX: 0000000000000000 RSI: ffffffff8d9ba191 RDI: ffffffff8be33e80
RBP: ffffc900065e7ef0 R08: ffffffff8fa3a937 R09: 1ffffffff1f47526
R10: dffffc0000000000 R11: fffffbfff1f47527 R12: dffffc0000000000
R13: 0000000000000000 R14: ffff888022151cc0 R15: 1ffff11026cc7551
 __schedule+0x19e0/0x4cc0
 schedule+0x165/0x360
 irqentry_exit_to_user_mode+0x5d/0x120
 asm_sysvec_call_function_single+0x1a/0x20
RIP: 0033:0x7f56fdb8eba9
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:00007f56feb01038 EFLAGS: 00000246
RAX: 0000000000000009 RBX: 00007f56fddd5fa0 RCX: 00007f56fdb8eba9
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000480
RBP: 00007f56fdc11e19 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f56fddd6038 R14: 00007f56fddd5fa0 R15: 00007fff54490108
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10504 jiffies! g9777 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=4447
rcu: rcu_preempt kthread starved for 10505 jiffies! g9777 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:27160 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>
