rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10502 jiffies, g=15573, q=410 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294960702-4294950200), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g15573 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=6030
rcu: rcu_preempt kthread starved for 10502 jiffies! g15573 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200 ->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:R stack:27448 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>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 7249 Comm: syz.0.382 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+0x6c9/0xd20
Code: 08 00 00 00 e8 88 25 00 00 45 31 ff 85 c0 0f 84 f5 05 00 00 83 3d 36 a9 0e 18 00 75 13 48 63 44 24 20 48 0f a3 05 a7 19 0b 12 <0f> 83 15 05 00 00 31 ed 48 8b 3c 24 4c 8b bf e0 0a 00 00 48 83 7c
RSP: 0000:ffffc90006e77690 EFLAGS: 00000047
RAX: 0000000000000067 RBX: 0000000000000002 RCX: ffffffff9349e388
RDX: 0000000000000008 RSI: ffff88802dc26130 RDI: ffff88802dc25640
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81ada78b
R10: dffffc0000000000 R11: ffffed1009604f51 R12: ffffffffffffff02
R13: 0000000000000002 R14: ffff88802dc26130 R15: 0000000000000000
FS:  00007f4a3c5ef6c0(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 0000000113850000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000082
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 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+0x52/0xc0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0033:0x7f4a3b78eba9
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:00007f4a3c5ef0e8 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 00007f4a3b9d5fa8 RCX: 00007f4a3b78eba9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f4a3b9d5fac
RBP: 00007f4a3b9d5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4a3b9d6038 R14: 00007fffbb6467d0 R15: 00007fffbb6468b8
 </TASK>
