rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=427481, q=333 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295127719-4295117217), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g427481 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=98651
rcu: rcu_preempt kthread starved for 10502 jiffies! g427481 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:26944 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x1550/0x5060
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 rcu_gp_fqs_loop+0x312/0x1560
 rcu_gp_kthread+0x9d/0x3b0
 kthread+0x726/0x8b0
 ret_from_fork+0x5b0/0xb20
 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: 38 Comm: kcompactd0 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:_find_first_zero_bit+0x2e/0xb0
Code: 41 57 41 56 41 55 41 54 53 48 85 f6 74 46 48 89 f3 49 89 fe 49 bc 00 00 00 00 00 fc ff df 48 89 f8 48 c1 e8 03 42 80 3c 20 00 <74> 08 4c 89 f7 e8 e8 37 92 fd 49 8b 06 48 83 f8 ff 74 2b 45 31 ed
RSP: 0018:ffffc90000ae7678 EFLAGS: 00000046
RAX: 1ffff1102000eaa2 RBX: 0000000000000002 RCX: dffffc0000000000
RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff888100075510
RBP: 0000000080000000 R08: ffff888100075393 R09: 1ffff1102000ea72
R10: dffffc0000000000 R11: ffffed102000ea73 R12: dffffc0000000000
R13: 1ffffffff1b8ca99 R14: ffff888100075510 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8882a9a22000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fde50841868 CR3: 000000010d81d000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000008000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 mm_get_cid+0xc7/0x130
 __schedule+0x222f/0x5060
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 kcompactd+0x415/0x12a0
 kthread+0x726/0x8b0
 ret_from_fork+0x5b0/0xb20
 ret_from_fork_asm+0x1a/0x30
 </TASK>
