Although the actual changes to the way you set up the processor to run SMP are fairly minor, the fact that you're running on a multicore system can have a major impact on your software!
The main thing to keep in mind is this: in a single processor environment, it may be a nice "design abstraction" to pretend that threads execute in parallel; under a multicore system, they really do execute in parallel! (With BMP, you can make your threads run on a specific CPU.)
In this section, we'll examine the impact of multicore on your system design.