How to dump stack for kernel threads

How to dump stack for kernel threads

[Larry Finger]

In a driver that I am debugging, there is a periodic task that runs every minute. Intermittently, it 
destructively interrupts some other activity in the driver, but I have not been able to find the 
section that is not thread-safe. I have included a dump_stack call at the point where the problem is 
evident, but the current thread is OK. How would I generate a stack dump of the rest of this 
driver's kernel threads? Dumping all kernel threads would also be OK.

Thanks,

Larry

Re: How to dump stack for kernel threads

[Jan Engelhardt]

>Subject: How to dump stack for kernel threads
>
> In a driver that I am debugging, there is a periodic task that runs every
> minute. Intermittently, it destructively interrupts some other activity in the
> driver, but I have not been able to find the section that is not thread-safe. I
> have included a dump_stack call at the point where the problem is evident, but
> the current thread is OK. How would I generate a stack dump of the rest of this
> driver's kernel threads? Dumping all kernel threads would also be OK.

Sysrq+T. Behind the jungle, there's a function doing what you want.


Jan Engelhardt
-- 
| Software Engineer and Linux/Unix Network Administrator
| Alphagate Systems, http://alphagate.hopto.org/
| jengelh's site, http://jengelh.hopto.org/

Re: How to dump stack for kernel threads

[Larry Finger]

Jan Engelhardt wrote:
>>In a driver that I am debugging, there is a periodic task that runs every
>>minute. Intermittently, it destructively interrupts some other activity in the
>>driver, but I have not been able to find the section that is not thread-safe. I
>>have included a dump_stack call at the point where the problem is evident, but
>>the current thread is OK. How would I generate a stack dump of the rest of this
>>driver's kernel threads? Dumping all kernel threads would also be OK.
> 
> 
> Sysrq+T. Behind the jungle, there's a function doing what you want.
> 
> 
> Jan Engelhardt

Thanks for the tip. It won't work for me from the keyboard but your suggestion got me into a call to 
handle_sysrq.

Larry