having trouble with kdb on smp (kernel 2.5.9)

[Matthew C Dobson]

Keith Owens wrote:

>On Fri, 17 May 2002 15:01:07 -0700, 
>Matthew Dobson <colpatch at us.ibm.com> wrote:
>
>>Keith Owens wrote:
>>
>>>On Wed, 15 May 2002 18:03:29 -0700,
>>>Patricia Gaughen <gone at us.ibm.com> wrote:
>>>
>>>>2.5.9 on an 8 proc numaq box.  I saw the recent patch from Ethan Solomita and
>>>>I'll give it a try tonight or tomorrow.  But we've ran into a couple of issues:
>>>>
>>>>      - when the system hangs we enter kdb but using bt, bta and btp do not produce
>>>>stacks for any of the processes.  We're able to get the stacks manually, but
>>>>this is not much fun :-)
>>>>
>>>Which version of gcc?  Newer versions of gcc produce stack frame code
>>>that kdb cannot backtrace without CONFIG_FRAME_POINTER=y.
>>>
>>I'm currently using gcc version 3.0.2.  And I definitely do have
>>CONFIG_FRAME_POINTER turned on.
>>
>
>Any error messages?  I am guessing that it says "Stack is not in
>task_struct, backtrace not available".  task_struct data has been moved
>around in recent 2.5 kernels and kdb has not been changed to validate
>the new layout yet.
>
Yep...  That the error message that I get... The latest kdb on the 
oss.sgi site is based on 2.5.7 which has the new task_struct changes, so 
I figured it would know how to find the stack... Like I said, we've been 
able to do it manually, by locating the thread_info in task_struct, and 
then manually dumping the 2 pages of memory sitting there...  The 
back-trace functionality would be nice, but isn't strictly necessary... 
 What would be really helpful is if I could look at what other cpus are 
doing...

Thanks!

-Matt