RE: Samba

[Kevin Musick <KMusick@teldar.com>]

Neal H Warfield wrote:
> If we reimplement mach over an exokernel, it will only decrease
> the microkernel's portability -- we now have a dependency on an
> exokernel rather then a generic piece of hardware.

What's the difference?  Either you port the Mach microkernel or you port the
exokernel.  In either case, you have localized machine dependent operations
to a small portion of the overall system code.

> Additionally, it will not increase performance; the current killer
> with the hurd/mach is the number of context switches to do any amount
> of work (look in the archives for a discussion of this topic).  Will
> an exokernel decrease the number of context switches?  Unlikely,
> however, I am open to suggestions.

The very goal of the exokernel design is to reduce the number of context
switches required.

Check out the site at http://www.pdos.lcs.mit.edu/exo.html.  This gives a
brief introduction.  They implemented a Web server on the kernel, called
Cheetah, which ran eight times faster than NCSA.  You can also obtain
volumes of information by going to www.mit.edu and doing a search on
"exokernel."

Kevin Musick
kmusick@teldar.com