GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	(detected by 0, t=10502 jiffies, g=81633, q=237 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294993798-4294983296), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g81633 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x200
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=22802
rcu: rcu_preempt kthread starved for 10502 jiffies! g81633 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:27544 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_timeout+0x158/0x2c0
 rcu_gp_fqs_loop+0x312/0x11d0
 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 13858 Comm: syz.1.2077 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__sanitizer_cov_trace_pc+0x5c/0x70
Code: a8 16 00 00 83 fa 02 75 21 48 8b 91 b0 16 00 00 48 8b 32 48 8d 7e 01 8b 89 ac 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 <e9> 3f 75 e5 09 cc 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90
RSP: 0018:ffffc90000a08dd0 EFLAGS: 00000006
RAX: ffffffff81b27751 RBX: ffff8881bbaf4338 RCX: ffff88810c1fd880
RDX: 0000000000010000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffff8881bbaf4300 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520001411ac R12: ffff88823c628280
R13: 1ffff110478c507a R14: ffff88823c628420 R15: dffffc0000000000
FS:  00007f8622bb76c0(0000) GS:ffff8882a9291000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8622bb6ff8 CR3: 000000010f68e000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 __hrtimer_run_queues+0x4c1/0xa20
 hrtimer_interrupt+0x44b/0x950
 __sysvec_apic_timer_interrupt+0x102/0x430
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:lock_acquire+0x221/0x350
Code: ff ff ff e8 e1 84 06 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 cb 4f 97 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 98 68 92
RSP: 0018:ffffc90007e9fb90 EFLAGS: 00000286
RAX: 08e81851e741e800 RBX: 0000000000000000 RCX: 0000000080000001
RDX: 000000006c614800 RSI: ffffffff8e21c286 RDI: ffffffff8c28b4e0
RBP: ffffffff81b9357d R08: ffffffff81b9357d R09: ffff88811432a3e0
R10: dffffc0000000000 R11: ffffed1022865479 R12: 0000000000000000
R13: ffff88811432a3e0 R14: 0000000000000001 R15: 0000000000000246
 _raw_spin_lock+0x2e/0x40
 futex_wake+0x1dd/0x580
 do_futex+0x395/0x420
 __se_sys_futex+0x3a8/0x450
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8621d9cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8622bb70e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f8622016098 RCX: 00007f8621d9cdd9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f862201609c
RBP: 00007f8622016090 R08: 3fffffffffffffff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8622016128 R14: 00007ffe970fd200 R15: 00007ffe970fd2e8
 </TASK>
