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Re: [f-cpu] Winograd DCT on my seul.org account



hi,

Michael Riepe wrote:
> On Tue, Apr 23, 2002 at 05:27:21AM +0200, Marco Al wrote:
> > Michael Riepe wrote:
> > > Threads work best if they don't have to communicate with each other,
> > > no matter if they're running on 1 CPU or 1000.  Communication usually
> > > means that you have to synchronize the sender and receiver thread, and
> > > the faster one will have to wait. In an MP system, you can run another
> > > thread instead, but synchronization and context switching still take
> > > some time -- and the more threads communicate with each other, the more
> > > synchronization overhead you'll have. Therefore, `fine-grained' threading
> > > doesn't work well (e.g. threads that return quickly or communicate a lot).
> > Depends on the architecture.

of course. but usually, we speak about "classic RISC" on this list.

> > "We can even use threads of about 10 instructions to achieve efficient
> > parallel execution"
> > from http://www.computer.org/micro/mi2000/pdf/m4012.pdf

oh, _that_ paper...
 
> Nice. If you do it in hardware, you can of course fork and synchronize
> threads much faster.

i don't remember well, but even though synchronisation is rather fast
(through common registers or something like that), _communication_
and _programming_ is another subject... and i don't even speak about
extensibility (and binary compatibility) because it looks like
an ASIC that has a very specific application (speech recognition).

>  Michael "Tired" Riepe <Michael.Riepe@stud.uni-hannover.de>


Juergen Goeritz wrote:
> On Wed, 24 Apr 2002, Michael Riepe wrote:
> >> "We can even use threads of about 10 instructions to achieve efficient
> >> parallel execution"
> >>
> >> from http://www.computer.org/micro/mi2000/pdf/m4012.pdf
> >
> >Nice. If you do it in hardware, you can of course fork and synchronize
> >threads much faster.
> 
> that's the way in the future anyway...

and it will remain so for a long time ;-P
(that what they said about InP and AsGa for a while and it still holds)

> JG
WHYGEE
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