rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=e46c/1/0x4000000000000000 softirq=15559/15559 fqs=0
rcu: 	(detected by 0, t=10502 jiffies, g=7449, q=170 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6109 Comm: syz.2.60 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:hrtimer_cancel+0x33/0x50
Code: e8 42 15 12 00 48 89 df e8 9a f9 ff ff 89 c5 31 ff 89 c6 e8 6f 19 12 00 85 ed 78 0c e8 26 15 12 00 eb 1a e8 1f 15 12 00 f3 90 <48> 89 df e8 75 f9 ff ff 85 c0 78 ed 89 c5 e8 0a 15 12 00 89 e8 5b
RSP: 0000:ffffc900064078d0 EFLAGS: 00000006
RAX: ffffffff81adabe1 RBX: ffff88803da30de8 RCX: ffff888021829cc0
RDX: 0000000000010000 RSI: 0000000000000004 RDI: 00000000ffffffff
RBP: 00000000ffffffff R08: ffff888136627a83 R09: 1ffff11026cc4f50
R10: dffffc0000000000 R11: ffffed1026cc4f51 R12: ffff88803da30e90
R13: dffffc0000000000 R14: ffff88803da30de8 R15: ffffffffffff5f05
FS:  00007fac410896c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1dbf3fdfc8 CR3: 000000010f516000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 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: 0033:0x7fac410d2af3
Code: 41 89 fd 49 c1 e5 04 4b 8d 1c 2e 48 83 c3 28 49 b9 ff ff ff ff ff ff ff 7f 49 ba ff ff ff ff ff ff ff 3f 4d 8d 62 01 45 8b 3e <41> f6 c7 01 75 4d 41 8b 46 04 83 f8 01 75 56 0f ae e8 0f 31 48 c1
RSP: 002b:00007fac41088fd0 EFLAGS: 00000202
RAX: 0000000000000002 RBX: 00007fac410cc038 RCX: 0000000000000001
RDX: 00007fac4029ade0 RSI: 00007fac410890b0 RDI: 0000000000000001
RBP: 00007fac41089040 R08: 0000000000000000 R09: 7fffffffffffffff
R10: 3fffffffffffffff R11: 0000000000000246 R12: 4000000000000000
R13: 0000000000000010 R14: 00007fac410cc000 R15: 000000000000306a
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g7449 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=2432
rcu: rcu_preempt kthread starved for 10502 jiffies! g7449 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27656 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>
