rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10505 jiffies, g=15509, q=375 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10501 (4294960427-4294949926), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10500 jiffies! g15509 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=6916
rcu: rcu_preempt kthread starved for 10501 jiffies! g15509 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:26664 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: 7660 Comm: syz.1.579 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 a2 15 12 00 48 89 df e8 9a f9 ff ff 89 c5 31 ff 89 c6 e8 cf 19 12 00 85 ed 78 0c e8 86 15 12 00 eb 1a e8 7f 15 12 00 f3 90 <48> 89 df e8 75 f9 ff ff 85 c0 78 ed 89 c5 e8 6a 15 12 00 89 e8 5b
RSP: 0018:ffffc900001e0990 EFLAGS: 00000006
RAX: ffffffff81adb021 RBX: ffff888024afcc68 RCX: ffff88810b0f1cc0
RDX: 0000000000010000 RSI: 0000000000000004 RDI: 00000000ffffffff
RBP: 00000000ffffffff R08: ffff888136627a83 R09: 1ffff11026cc4f50
R10: dffffc0000000000 R11: ffffed1026cc4f51 R12: ffff888024afcd10
R13: dffffc0000000000 R14: ffff888024afcc68 R15: ffffffffffff1d07
FS:  00007f41da1326c0(0000) GS:ffff8881a3c11000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32163fff CR3: 000000010df22000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 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:do_syscall_64+0xc3/0x3b0
Code: 00 48 8b 7d 08 48 89 7b 18 e8 09 5a 00 00 0f 1f 44 00 00 0f 1f 44 00 00 90 e8 79 bf 4c f6 90 90 e8 22 bf 4c f6 fb 49 8b 57 08 <f6> c2 3f 74 0e 4c 89 f7 4c 89 ee e8 3d b2 2f f6 49 89 c4 90 90 41
RSP: 0018:ffffc90006c87ef0 EFLAGS: 00000286
RAX: bfae01d447d06b00 RBX: ffffc90006c87ef0 RCX: bfae01d447d06b00
RDX: 0000000000000000 RSI: ffffffff8d9baef1 RDI: ffffffff8be34480
RBP: ffffc90006c87f48 R08: ffffffff8fa3b537 R09: 1ffffffff1f476a6
R10: dffffc0000000000 R11: fffffbfff1f476a7 R12: 00000000000000ca
R13: 00000000000000ca R14: ffffc90006c87f58 R15: ffff88810b0f1cc0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f41d938ec29
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:00007f41da1320e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f41d95d5fa8 RCX: 00007f41d938ec29
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f41d95d5fac
RBP: 00007f41d95d5fa0 R08: 7fffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f41d95d6038 R14: 00007ffec509ade0 R15: 00007ffec509aec8
 </TASK>
