rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10506 jiffies, g=25533, q=329 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10506 (4294966547-4294956041), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g25533 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=12990
rcu: rcu_preempt kthread starved for 10506 jiffies! g25533 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:26920 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: 9046 Comm: syz.1.893 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+0x29e/0xd20
Code: 00 4c 89 6c 24 28 4a 8d 04 ad 00 00 00 00 4c 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
RSP: 0018:ffffc90000007750 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffff88804b027a98 RCX: 0000000000000067
RDX: 00000000000c4067 RSI: 0000000000000067 RDI: ffff888109c01cc0
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81ada78b
R10: dffffc0000000000 R11: ffffed1009604f51 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: ffff888109c027b0
FS:  00007fae67db66c0(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 0000000039d9a000 CR4: 00000000000006f0
DR0: 0000200000000080 DR1: 0000000000000000 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+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:__mutex_unlock_slowpath+0x6a5/0x740
Code: 48 8d bc 24 88 00 00 00 e8 b8 84 a7 f6 48 89 9c 24 88 00 00 00 bf 01 00 00 00 e8 76 50 14 f6 65 8b 05 ff 10 25 07 85 c0 74 55 <48> c7 44 24 40 0e 36 e0 45 48 b8 00 00 00 00 00 fc ff df 48 8b 4c
RSP: 0018:ffffc90007237ae0 EFLAGS: 00000246
RAX: ffff888109c01cc0 RBX: 1ffffffff1f47b4c RCX: ffffffff8b7bba31
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffc90007237b80
RBP: ffffc90007237bf0 R08: ffffc90007237b87 R09: 1ffff92000e46f70
R10: dffffc0000000000 R11: fffff52000e46f71 R12: ffffc90007237b80
R13: 0000000000000000 R14: 1ffffffff3358464 R15: ffff88802fd0f440
 perf_ioctl+0xdaa/0x1ec0
 __se_sys_ioctl+0xfc/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fae66f8eba9
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:00007fae67db6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fae671d5fa0 RCX: 00007fae66f8eba9
RDX: 0000000000000008 RSI: 0000000000002402 RDI: 000000000000000e
RBP: 00007fae67011e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fae671d6038 R14: 00007fae671d5fa0 R15: 00007ffc364a6678
 </TASK>
