Guess I'll hang on to my Hasselblad V

On Wed, 15 Jul 2009 18:22:47 -0400, Alan Browne wrote:

Stefan Patric wrote:

I don't even think the Mach kernel is still in development by the
originators. Apple, I've read, has taken it over for their own
purposes.

It would appear. The claim that it is the Mach kernel is from Wikipedia
which is usually reliable for "nerd" input.

Apple took the Mach kernel and massaged it to suit its purposes for OS
X. I don't know if that code is available, but under the Open Source
license, it's suppose to be.

Although, I'm sure Mach, in some form or other, is floating
around the open source development community. There are some, me
included, that prefer micro-kernels over Linux and BSD's standard
monolithic ones. They each have their advantages and disadvantages.

At the level I use them, probably no difference. However one important
change to Mac OS X will come out in the 10.6 release this late summer.

Very generally, monolithic kernels work best with servers while micros
are more suitable for desktops.

Part of it is to get full benefit of 64 bit processors and the rest,
perhaps more important is for multi core / multi CPU environments. The
OS has changed how tasks are queued for execution in order that
resources be maximized without application programmers needing to worry
much about the target CPU architecture. Mo
http://www.apple.com/macosx/technology/#grandcentral

Sounds like the way cluster supercomputer kernel-OSes work, so that how
the app is distributed and executed through the cluster is transparent to
the user, and doesn't require special compiling of the app itself.

as well as the use of the graphics processor as an additional CPU
(OpenCL) - requires Apps to be compiled for it however. (Same link
above). [Not sure if my machine will support that however].

Don't know about the Mac, but I read a couple years ago, that some team
was working on a Linux kernel that would automatically distribute
execution of the OS, apps, etc. over multi-core/multi-cpus without the
need for custom compile of anything except the kernel.

Ain't progress grand?


Stef

In article , Stefan Patric
wrote:

I don't even think the Mach kernel is still in development by the
originators. Apple, I've read, has taken it over for their own
purposes.

It would appear. The claim that it is the Mach kernel is from Wikipedia
which is usually reliable for "nerd" input.

Apple took the Mach kernel and massaged it to suit its purposes for OS
X.

actually next did for nextstep/openstep and apple inherited that.

I don't know if that code is available, but under the Open Source
license, it's suppose to be.

it's available.