> I'm getting the impression that most folk on this list consider a Big
> Lock (which I _assume_ refers to allowing all CPU's to run kernel mode
> and field interrupts, with mutual exclusion) as the first goal towards
> SMP.   Much preliminary work appears to have been done towards this end.

Sorry, I think I see the plan now... the Big Lock with
simple_lock_try() and a separate spin lock for the run queue - so that
cpu's that cannot gain the "kernel" lock can still go look for a user
process to run, is effectively the same as master/slave without the
need for multiple run queues or a fixed master cpu.  More of a a step
in the right direction even though its a lot more work to get to first
base.

--sjg