To Linus: kdb in 2.4?

To Linus: kdb in 2.4?

[LA Walsh]

I'm wondering about the possibility of re-examining the idea of a kernel debugger
option distributed with 2.4.  

I'm thinking that it could be a great teaching tool to break and examine structures,
variables, process states, as well as an aid to people who may not have a grasp
of the entire kernel but need to write device drivers.

It's easy for someone who's "grown up" with Linux to know it all so thoroughly 
that such a tool seems fluff.  But even the best mechanics on new cars use complex
diagnostic tools to do car repair.  Sure there may be experts that designed the engine
that wouldn't need it, but large numbers of people need to repair cars or modify them for
their purposes.  Having tools to aid in that isn't so much a crutch as it is
a learning tool.  It's like being able to look at the characters of the alphabet
individually before one learns to comprehend the entirety of the writings of Buddha.

Certainly Buddha doesn't need to know how to read to know his own writings -- and
certainly, if everyone meditates and 'evolves' to their Buddha nature, they wouldn't
need to read the texts or recognize the letters either.  

But not everyone is at the same place on the mountain (or even the same mountain, for
that matter).

In wisdom, one would, I posit, understand others are in different places and may
find it useful to have tools to learn to read before they comprehend.  

Just my 2-4 cents on the matter...
-- 
L A Walsh                        | Trust Technology, Core Linux, SGI
law@sgi.com                      | Voice: (650) 933-5338

Re: To Linus: kdb in 2.4?

[Jeff Dike]

law@sgi.com said:
> I'm wondering about the possibility of re-examining the idea of a
> kernel debugger option distributed with 2.4.   

First off, I'd like to say that I'm highly sympathetic to this, assuming that 
a kernel debugger doesn't change the kernel's behavior.

However, 

> I'm thinking that it could be a great teaching tool to break and
> examine structures, variables, process states, as well as an aid to
> people who may not have a grasp of the entire kernel but need to write
> device drivers. 

you might look at UML (http://user-mode-linux.sourceforge.net) for this.  A 
number of kernel hackers are very successfully using UML for doing filesystem 
and mm development and debugging.  With some help from the host, it's also 
possible to do driver development under UML.

I also know of a number of people using UML to further their education by 
using it to poke around a running kernel.

> Certainly Buddha doesn't need to know how to read to know his own
> writings -- and certainly, if everyone meditates and 'evolves' to
> their Buddha nature, they wouldn't need to read the texts or recognize
> the letters either.   

So, if you can't convince Buddha of the wisdom of your arguments (or even if 
you can) check out UML.  It makes a perfectly good kernel debugger available, 
and it's a lot easier to deal with than a native kernel.

				Jeff

Re: To Linus: kdb in 2.4?

[Hacksaw]

Shhhh! Do not nudge sleeping penguin. Here is blow-by-blow of last incident:

http://kt.linuxcare.com/kernel-traffic/kt20001002_87.epl#1