Re: Please read if you use x86 -current

[Antti Kantee <pooka%cs.hut.fi@localhost>]

On Wed Nov 12 2008 at 21:40:00 +0100, vincent wrote:
> Le 12 nov. 08 à 21:37, Adam Hamsik a écrit :
> 
> >>
> >>Do you plan to move away further core kernel modules, like UVM or  
> >>VFS ?
> >
> >What do you mean with this ? Both UVM and VFS are core kernel parts  
> >and they
> >can't be moved away, but POSIX semaphores are not core kernel part  
> >and can be
> >modularized easily.

vm pagers, however, could be.  And actually at some point I want to look
at doing that.

> I mean, is this somehow a (maybe hidden or unconscious) first move  
> into evolving NetBSD kernel in a Mach-like direction?

Well, if you want the *first* step in moving to a Mach-like direction,
you need to go waaaay back in history to CSRG.  But mostly moving into a
Mach-style direction is pointless.  A single-server is a ridiculous idea.
And a multiserver suffers both from performance problems (without very
very careful tuning for the hardware) and is still a ridiculous idea: why
would I want to run e.g. my rootfs as a server?  If it crashes, I'm pretty
much screwed.  There is a lot of functionality I want in kernel space.

However, having the system composed of well-defined components and
having the option for distributed operation (of which a separate address
space within a single machine is a special case) for some components
makes sense.  Chunking everything into separate servers because it's
"better" doesn't.