I don't know enough about rump to talk more definitively, and in fact I've failed to find an overview about what it is technically, how it works on NetBSD, how it works outside NetBSD, etc. Does running rump on Linux provide the SMP scalability improvements one misses with NetBSD's kernel for instance? Can you point me at something to read that's short enough to digest in an hour?
Follow the "Getting Started" link on rumpkernel.org. That page includes both short and long reading (should you get more interested ;), and also some "hands on" tutorials should you learn about things better that way (I know I do).
SMP scalability is all about bottlenecks. If the driver is the bottleneck, it won't scale no matter where you run it.
