The Soul of Barb's New Machine was creat 1150

(the post I'm hoping to respond to here didn't actually make it to my cite, so I'm really responding to the first response to it that did. If I've got the attribution wrong, I apologize).

The superiority that the microkernel was supposed to have was in better encapsulation of the OS components, mainly through having them in separate address spaces (that's just a part of it, but it's the part that's relevant to my comment). But this meant that a call to just about anything required a context switch to the filesystem, then a context switch to the actual device driver, then a context switch back to the filesystem, then a context switch back to the user process. And a message pbutted with each of those context switches. This is from memory, so I may have missed some context switches and messages in there.

To try to make this less horrible, all the OS components were put into a single address space, just like in a monolithic OS.

The result was that performance was indeed terrible (all those messages were still pbutted around), but not as terrible as it would have been. -- Joseph J. Pfeiffer, Jr., Ph.D. Phone -- (505) 646-1605 Department of Computer Science FAX -- (505) 646-1002