Re: An issue of kernel stall caused by infiniband mad packet

[Leon Romanovsky]

On Wed, Feb 22, 2023 at 08:40:52PM +0800, Yacan Liu wrote:
> Hi folks:
> 
>   We recently encountered a kernel stall issue related to infiniband mad
> packet. We believe this is caused by some abnormal operations of user-level
> programs.But I am not sure if the kernel driver needs to do some protection.
> 
> In our cluster, multiple nodes will establish multiple RDMA connections with
> each other. Then, when we start the program, the kernel prompts the
> following error after one minute:
> 
> [ 5489.530125] rcu: INFO: rcu_sched self-detected stall on CPU
> [ 5489.535714] rcu:     55-....: (19027 ticks this GP)
> idle=236/1/0x4000000000000000 softirq=13510/13510 fqs=4359
> [ 5489.545554]  (t=21015 jiffies g=279845 q=701559)
> [ 5489.545557] NMI backtrace for cpu 55
> [ 5489.545559] CPU: 55 PID: 44979 Comm: kworker/u196:1 Tainted: G    OE
> 5.10.91-netease3-1 #2
> [ 5489.545560] Hardware name: Inspur SA5212M5/YZMB-00882-10T, BIOS 4.1.21
> 08/25/2021
> [ 5489.545582] Workqueue: ib-comp-unb-wq ib_cq_poll_work [ib_core]
> [ 5489.545584] Call Trace:
> [ 5489.545586]
> [ 5489.545590]  dump_stack+0x6b/0x83
> [ 5489.545593]  nmi_cpu_backtrace.cold+0x32/0x69
> [ 5489.545596]  ? lapic_can_unplug_cpu+0x80/0x80
> [ 5489.545599]  nmi_trigger_cpumask_backtrace+0xd7/0xe0
> [ 5489.545602]  rcu_dump_cpu_stacks+0xa2/0xd0
> [ 5489.545604]  rcu_sched_clock_irq.cold+0x1ff/0x3d6
> [ 5489.545607]  ? trigger_load_balance+0x5a/0x240
> [ 5489.545610]  update_process_times+0x8c/0xc0
> [ 5489.545613]  tick_sched_handle+0x22/0x60
> [ 5489.545615]  tick_sched_timer+0x7c/0xb0
> [ 5489.545617]  ? tick_do_update_jiffies64.part.0+0xc0/0xc0
> [ 5489.545619]  __hrtimer_run_queues+0x12a/0x270
> [ 5489.545621]  hrtimer_interrupt+0x110/0x2c0
> [ 5489.545623]  __sysvec_apic_timer_interrupt+0x5f/0xd0
> [ 5489.545627]  asm_call_irq_on_stack+0xf/0x20
> [ 5489.545627]
> [ 5489.545629]  sysvec_apic_timer_interrupt+0x72/0x80
> [ 5489.545631]  asm_sysvec_apic_timer_interrupt+0x12/0x20
> 
> OS:  Debian 11
> Kernel: 5.10.91
> ofed: MLNX_OFED_LINUX-5.5-1.0.3.2

Please approach your NVidia support representative. There are some
differences between upstream and MOFED code in MAD area.

Thanks