how to avoid CPU watchdog error during debug

[Philipp Hortmann]

On 8/25/21 3:06 AM, ckim at etri.re.kr wrote:
> Hello,
> 
> While debugging a kernel module, I get this error and the OS crashes.
> 
> [39068.833652] rcu: INFO: rcu_sched self-detected stall on CPU
> 
> [39068.834739] watchdog: BUG: soft lockup - CPU#3 stuck for 164s! 
> [systemd-journal:399]
> 
> [39068.834854] watchdog: BUG: soft lockup - CPU#0 stuck for 164s! 
> [test_axpu_app:2896]
> 
> This seems because I stopped the processor for debugging.
> 
> How can I avoid this watchdog error during debug?
> 
> Any help will be appreciated. Thanks!
> 
> Chan Kim
> 
> 
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
> 

Hi Kim,

since many things are time depending in the kernel it is difficult to 
stop parts of the kernel. The question is if it is really absolutely 
necessary to do this? Why you can not do it by logging with printk?

Debugging is described in:
https://www.doc-developpement-durable.org/file/Projets-informatiques/cours-&-manuels-informatiques/Linux/Linux%20Kernel%20Development,%203rd%20Edition.pdf

See Chapter 18 Debugging

Thanks! Bye Philipp