KDB enhancements

[linas@xxxxxxxxxxxxxx]

Hi Keith,

I'm vaguely daydreaming about a few KDB enhancements, I was curious if 
you've thought about them:

-- 'cat /proc/meminfo'  Turns out one bug I was chasing was OOM on
   a machine with 32GB of RAM (!) and it took me days to even think
   of looking there.

-- Support for examining structures symbolically.  I've had to walk
   the buffer cache by hand in the past, I've walked task struct
   by hand yesterday, and they guy down the hall stares at network
   structs.  

   I don't know if it would be better to handle a few of these as 
   special-cases in some simple manner, or if some more complex but
   generic mechanism would be better ... 

--linas