rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10502 jiffies, g=100029, q=656 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295007761-4294997259), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g100029 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=39403
rcu: rcu_preempt kthread starved for 10502 jiffies! g100029 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: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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17375 Comm: syz.0.3013 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:do_raw_spin_lock+0x12e/0x290
Code: 00 48 89 df be 04 00 00 00 e8 9e d2 85 00 48 8d 7c 24 40 be 04 00 00 00 e8 8f d2 85 00 8b 44 24 40 b9 01 00 00 00 f0 0f b1 0b <0f> 85 dd 00 00 00 65 8b 1d 29 d7 02 11 48 b9 00 00 00 00 00 fc ff
RSP: 0018:ffffc900000077c0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff88804b027a80 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000007800
RBP: ffffc90000007870 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000000f00 R12: ffff88804b027a90
R13: ffff88804b027a88 R14: 1ffff11009604f52 R15: 1ffff11009604f51
FS:  00007f03f8a076c0(0000) GS:ffff8880b8611000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 000000003b674000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000082
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 _raw_spin_lock_irqsave+0xb3/0xf0
 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:exit_to_user_mode_loop+0x45/0x110
Code: eb 1e e8 ee c9 d0 09 65 48 8b 04 25 08 f0 a0 92 4c 8b 30 41 f7 c6 1e 30 02 00 0f 84 c5 00 00 00 e8 b0 17 1d 00 fb 41 f6 c6 18 <74> 05 e8 24 d4 d1 09 41 f7 c6 00 10 00 00 74 08 48 89 df e8 a3 d2
RSP: 0018:ffffc9000336fed0 EFLAGS: 00000246
RAX: be6e30f35be8ac00 RBX: ffffc9000336ff58 RCX: be6e30f35be8ac00
RDX: 0000000000000000 RSI: ffffffff8d9baef1 RDI: ffffffff8be34480
RBP: ffffc9000336ff48 R08: ffffffff8fa3b537 R09: 1ffffffff1f476a6
R10: dffffc0000000000 R11: fffffbfff1f476a7 R12: 0000000000000000
R13: 000000000000012a R14: 0000000000000002 R15: ffff88801f705640
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f03f7b8ec29
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:00007f03f8a07038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffea RBX: 00007f03f7dd5fa0 RCX: 00007f03f7b8ec29
RDX: 000000000000000f RSI: 0000000000000000 RDI: 00002000000000c0
RBP: 00007f03f7c11e41 R08: 0000000000000002 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f03f7dd6038 R14: 00007f03f7dd5fa0 R15: 00007ffe1146fab8
 </TASK>
