How to debug kernels (was: cvs commit: src/sys/conf kern.post.mk)

[Garance A Drosihn]

[this will be a repeat to Greg, but I'll mention it publicly...]

At 10:21 AM +0930 9/12/05, Greg 'groggy' Lehey wrote:
>
>A lot must depend on how you use your debug kernel.  One of the
>biggest problems I've found is keeping the kernel and the sources
>in sync.  ...
>
>The method I use is described in
>http://wwww.lemis.com/grog/Papers/Debug-tutorial/tutorial.pdf.

This looks like a very useful document, which pulls together a
lot of information for the benefit of those developers who want
to work at the kernel-level.  I've only skimmed it over, but I
intend to read it in more detail later...

But I think David's change is a significant help for those users
who are not kernel developers, and who have no desire to become a
kernel developer.  Most of the time I am not debugging any kernel-
change of my own, for instance.  All I want from a debug kernel is
to have the information around if some other developer asks:
"Can you get a traceback from that coredump?".

I'll only care about the debug information *IF* my system hits a
panic, and that may not happen until weeks after I have built a
kernel.  A lot can happen in my /usr/obj directories in the course
of two weeks!  (especially if I am not *expecting* to need any of
the information in it).

More serious kernel developers would still want to check out the
information and follow the advice included your tutorial.  But
there are many users who are not working at that level of detail.

-- 
Garance Alistair Drosehn            =   gad at gilead.netel.rpi.edu
Senior Systems Programmer           or  gad at freebsd.org
Rensselaer Polytechnic Institute    or  drosih at rpi.edu