Somehow this feels related to the work that came out of Berkeley a year
or so ago. I'm still not convinced what is the benefits of multiple
kernels. If you are managing a couple of 100s of cores a single kernel
would do just fine, once the industry is ready for a couple dozen of
thousands PUs -- the kernel is most likely to be dispensed with anyway.
I'm not familiar with the berkeley work.
Did you find any ideas there particularly engaging?
I'm still digesting it. My first thoughts were that if my pc is a
distributed heterogeneous computer, what lessons it can borrow from
earlier work on distributed heterogeneous computing (ie. plan9).
I found the discussion on cache coherency, message passing and
optimization to be enlightening. The fact that you may want to
organize your core OS quite a bit differently depending on which
model cpus in the same family you use is kind of scary.
The mention that "... the overhead of cache coherence restricts the
ability to scale up to even 80 cores" is also eye openeing. If we're at
aprox 8 cores today, thats only 5 yrs away (if we double cores every
1.5 yrs).
Roman.
Tim Newsham
http://www.thenewsh.com/~newsham/
