"When we first started to learn about SMP systems, our
first thought was - gosh, don't they go on about caches a lot?
But it isn't just in parallel processing where the hairy
business of cache coherency is a problem, as we've seen with the
AMD Linux bug blame game. This has affected uniprocessor systems,
and I was stumped. But Reg readers have provided a wealth of
detail, and what follows will take you from a bird's eye view to
the low-level nasties.