kdb from COM1: doesn't work with ctrl-A

[slurn at verisign.com]

> 
> Hi Keith and the rest of the gang,
> 
> I would like to know some rather basic questions answered. I could not make 
> out much from the available documnetations.
> 
> The following are my questions:
> 
> 1) How is debugging done in a multi-processor environment ?

When an event of interest occurs, kdb will stop all processors. The
processor upon which the event occured will be the active processor
that KDB initially uses; you can switch processors using a kdb command.

> 2) Does kdb/kdgb support debugging in a SMP environment ?

kdb does.   I'm not sure if SMP support was added to kgdb.

> 3) Could anyone let me know the limitations kdb/kgdb has in an SMP environment?
> 4) Can non-maskable interrupts be sent across processors while debugging?

KDB uses NMI's to switch cpu's.    Other than that, NMI's are handled 
normally.  Note that while kdb is running on a CPU, the other CPU's are 
all halted (well, blocked anyway).

> 
> anyone has anyidea of Dprobes limitations and strenghts in the same context, please throw light on the same.

Sorry, don't know anything about Dprobes.

scott