[Eug-lug] Concurrency, (free lunch is over article)

[Bob Miller]

Mike Cherba wrote:

> I find it interesting that the article only covers one percieved facet
> of mutlicore performance and doesn't really cover effective division of
> work as the number of processors goes toward infinity.  While SMP is a
> good approach for 2 or even 4 processors, I do not believe it to be the
> best approach for numbers of cores higher than that.  Especially
> depending on the work to be done.  Once you have more than a few cores,
> you can afford to specialize the tasks of each core at an even lower
> level.  Certain functions work best with a single CPU focused on them.  

I don't understand what you're saying.  Are you advocating
special-purpose functional units a la PlayStation or video card, or
general-purpose CPUs given special jobs by system software?

> My concerns are that most software developers today do not understand
> how to design applications which effectively make use of multiple
> processing units.  

I keep hearing this.  I personally know lots of people who can
effectively design for SMP, NUMA or Beowulf systems.  Also, some
frameworks are useful for hiding concurrency from application
programmers (e.g., app servers, apache+mysql).  I don't think the
brain shortage is as severe as it's made out to be.

-- 
Bob Miller                              K<bob>
kbobsoft software consulting
http://kbobsoft.com                     kbob at jogger-egg.com