rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=20877, q=281 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294966458-4294955956), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g20877 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=12580
rcu: rcu_preempt kthread starved for 10502 jiffies! g20877 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200 ->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:R stack:26632 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 8632 Comm: syz.4.808 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:_raw_spin_unlock_irqrestore+0x6b/0x110
Code: ee 7c 8b 49 89 e7 49 c1 ef 03 48 b8 f1 f1 f1 f1 00 f3 f3 f3 49 bc 00 00 00 00 00 fc ff df 4b 89 04 27 48 83 c7 18 48 8b 75 08 <e8> e0 91 20 f6 4c 89 f7 e8 38 29 21 f6 f7 c3 00 02 00 00 74 05 e8
RSP: 0018:ffffc900001e0880 EFLAGS: 00000082
RAX: f3f3f300f1f1f1f1 RBX: 0000000000000802 RCX: ffff88810a83d640
RDX: 0000000000010000 RSI: ffffffff81ada91e RDI: ffff888136627a98
RBP: ffffc900001e0918 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200003c100 R12: dffffc0000000000
R13: ffff888136627b00 R14: ffff888136627a80 R15: 1ffff9200003c110
FS:  00007fc5613c36c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c389975 CR3: 0000000107048000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 hrtimer_try_to_cancel+0x3be/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:plist_del+0x0/0x3f0
Code: e1 07 80 c1 03 38 c1 0f 8c b8 fd ff ff 4c 89 f7 e8 55 01 ae f6 e9 ab fd ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <66> 0f 1f 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 28 48 89 f3 49
RSP: 0018:ffffc90006167b68 EFLAGS: 00000246
RAX: ffffffff81b3188f RBX: ffffc90006cd7aa0 RCX: 0000000000080000
RDX: ffffc90003601000 RSI: ffff888113a0e408 RDI: ffffc90006cd7aa0
RBP: 0000000000000001 R08: ffff88810846d66b R09: 1ffff1102108dacd
R10: dffffc0000000000 R11: ffffed102108dace R12: dffffc0000000000
R13: ffffc90006cd7ad0 R14: ffff888113a0e3c0 R15: ffff888113a0e3c8
 __futex_unqueue+0xf0/0x160
 futex_wake_mark+0xe2/0x200
 futex_wake+0x3bb/0x560
 do_futex+0x395/0x420
 __se_sys_futex+0x36f/0x400
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc56058eba9
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:00007fc5613c30e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fc5607d5fa8 RCX: 00007fc56058eba9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fc5607d5fac
RBP: 00007fc5607d5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc5607d6038 R14: 00007ffda7ac8040 R15: 00007ffda7ac8128
 </TASK>
