rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=61625, q=78 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294993518-4294983016), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g61625 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=21987
rcu: rcu_preempt kthread starved for 10502 jiffies! g61625 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:27224 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
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+0x4bc/0x870
 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: 15272 Comm: syz.7.2576 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_release+0x15b/0x3e0
Code: 0f 84 dd 00 00 00 48 85 ed 0f 84 19 01 00 00 83 7d 24 00 0f 85 ea 01 00 00 8b 45 20 3d 00 00 20 00 48 8b 5c 24 08 8b 54 24 14 <72> 25 89 c1 81 e1 00 00 e0 ff 25 ff ff 1f 00 01 c8 05 00 00 e0 ff
RSP: 0018:ffffc900001e0818 EFLAGS: 00000083
RAX: 00000000000c4068 RBX: 0000000000000083 RCX: 51c48dee131e7b00
RDX: 0000000000000001 RSI: ffff888136627ad8 RDI: ffff88812ab66258
RBP: ffff88812ab66258 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200003c100 R12: 0000000000000001
R13: 0000000000000001 R14: ffff888136627ad8 R15: ffff88812ab65700
FS:  00007fb6ab8e86c0(0000) GS:ffff8881a3a03000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffd000000 CR3: 000000001f1ba000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 _raw_spin_unlock_irqrestore+0x70/0x110
 hrtimer_try_to_cancel+0x3be/0x420
 hrtimer_cancel+0x3b/0x50
 cpu_clock_event_stop+0xd9/0x130
 __perf_event_overflow+0x580/0xe40
 perf_swevent_hrtimer+0x3b8/0x500
 __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:lock_acquire+0x175/0x360
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 9b d1 23 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc90003c078d8 EFLAGS: 00000206
RAX: 51c48dee131e7b00 RBX: 0000000000000000 RCX: 51c48dee131e7b00
RDX: 0000000000000000 RSI: ffffffff8dd8c8ae RDI: ffffffff8c03d4e0
RBP: ffffffff81b49257 R08: 0000000000000000 R09: ffffffff81b49257
R10: dffffc0000000000 R11: ffffed10245594f9 R12: 0000000000000000
R13: ffff888122aca7e0 R14: 0000000000000001 R15: 0000000000000246
 _raw_spin_lock+0x2e/0x40
 futex_wait_setup+0xd7/0x590
 __futex_wait+0x148/0x3d0
 futex_wait+0x104/0x360
 do_futex+0x333/0x420
 __se_sys_futex+0x36f/0x400
 do_syscall_64+0xfa/0xfa0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb6aa98ec29
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:00007fb6ab8e80e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fb6aabd5fa8 RCX: 00007fb6aa98ec29
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb6aabd5fa8
RBP: 00007fb6aabd5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb6aabd6038 R14: 00007ffd81e24530 R15: 00007ffd81e24618
 </TASK>
