rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 1, t=10505 jiffies, g=31013, q=186 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10505 (4294963477-4294952972), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10504 jiffies! g31013 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=8074
rcu: rcu_preempt kthread starved for 10505 jiffies! g31013 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:28192 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17d9/0x56c0
 schedule+0x164/0x2b0
 schedule_timeout+0x152/0x2c0
 rcu_gp_fqs_loop+0x30c/0x11f0
 rcu_gp_kthread+0x9e/0x2b0
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 0 Comm: swapper/0 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:rcu_is_watching+0x44/0xb0
Code: 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd d0 d7 4f 8e 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 2c bf 88 00 <48> c7 c3 d8 88 6e 93 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38
RSP: 0018:ffffc90000007d38 EFLAGS: 00000046
RAX: 1ffffffff1c9fafa RBX: 0000000000000000 RCX: 0000000080010003
RDX: 0000000000010000 RSI: ffffffff8c4bdd60 RDI: ffffffff8c4bdd20
RBP: ffff88801f823300 R08: ffff88801f823327 R09: 0000000000000000
R10: ffff88801f823318 R11: ffffed1003f04665 R12: ffff8881210281c0
R13: ffffffff81b3b03f R14: ffffffff8e4fd7d0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88818d94b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8daa627dac CR3: 000000016efae000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 lock_release+0x4b/0x3c0
 _raw_spin_unlock_irqrestore+0x1b/0x80
 __hrtimer_run_queues+0x2bf/0xa10
 hrtimer_interrupt+0x448/0x910
 __sysvec_apic_timer_interrupt+0x102/0x430
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:pv_native_safe_halt+0xf/0x20
Code: ac 7e 02 e9 93 06 03 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d d3 3e 18 00 fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8e807de0 EFLAGS: 00000202
RAX: 00000000001c259b RBX: ffffffff819b5450 RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8e22f108 RDI: ffffffff8c4bdd80
RBP: ffffffff8e807eb8 R08: ffff8881210338db R09: 1ffff1102420671b
R10: dffffc0000000000 R11: ffffed102420671c R12: 0000000000000000
R13: 1ffffffff1d11de8 R14: 1ffffffff1d00fc4 R15: dffffc0000000000
 default_idle+0x9/0x20
 default_idle_call+0x72/0xb0
 do_idle+0x2e0/0x540
 cpu_startup_entry+0x43/0x60
 rest_init+0x2de/0x300
 start_kernel+0x392/0x3e0
 x86_64_start_reservations+0x24/0x30
 x86_64_start_kernel+0x137/0x1b0
 common_startup_64+0x13e/0x157
 </TASK>
