Re: Linux, the microkernel (was Re: latest linus-2.5 BK broken)

Rob Landley
2002-06-22T18:23:16Z

On Saturday 22 June 2002 11:31 am, Alan Cox wrote:
> > A microkernel design was actually made to work once, with good
> > performance. It was about fifteen years ago, in the amiga. Know how they
> > pulled it off? Commodore used a mutant ultra-cheap 68030 that had -NO-
> > memory management unit.
>
> Vanilla 68000 actually. And it never worked well - the UI folks had
> to use a library not threads. The fs performance sucked

I dug through my notes a bit, and the interview I was thinking (with one of
the designers before he died, Jay Minor I think) said that when they did
upgrade to the 68030 (long after the A1000), they specifically comissioned an
MMU-less version (68EC030), and that if they'd had to deal with an MMU in the
first place he doubted they could ever have gotten a microkernel architecture
to work.

Unfortunately, all I have from said interview at the moment are the notes I
took. My first year of computer history research was a learning experience
about how to do research, back before I learned to store the URL the notes
came from with the notes (no, the fact it's in my bookmarks list doesn't mean
I can find it again), and to save pages to my hard drive becaue the links
have been known to go away over time... :)

On a side note, it's fun looking through the tanenbaum-torvalds debate
archive and see all the people holding up the amiga as an example of a
successful microkernel with decent performance, and note the lack of MMU...

Rob