It's All About Search ...
It's been "double the pleasure double the fun" on the back end for some time now. 4-way, 8-way, 16-way server processor configurations are pretty run-of-the-mill these days. All that server stuff has been multithreaded, multiprogrammed and multiprocessed, and at this point it's pretty much a done deal right? By server stuff I mean the database app, the web server, the e-mail server, the E-bay server, the World-of-Warcraft server, etc. Sure the programming is a little dicey. The debugging and testing is a little unpredictable and treacherous at times but we manage to pull it off. The server stuff runs just fast enough so that the user doesn't give up hope and continues to keep coming back. Mission accomplished right?Add to the server stuff those scientific-high-performance-earth-quake-modeling-weather-simulating-biomedical-gene-sequencing-cryptographic-breaking programs that routinely bring the most parallel of parallel computers to it knees wheezing and coughing in defeat and you have a reasonable picture of how most parallelism in software is used.
But for the moment (Ahem...) Tracey and I are stuck on a different wavelength (well of course we are). We are quite enthralled by the possibilities of cheap multicore (potentially massively multicore) computers and how they might help us quench our thirst for all things ICOT, certain ingredients of the Semantic Web, and a particularly nasty set of AI-Complete problems that we just can't get off of our plates. See, for us the computer's most important function is problem solving. Yea. we know that the YouTube.com junkies, the movie-music-chat-room-email-family-photo junkies might disagree with us. But that's okay we can still be cordial. Perhaps the most popular function of the computer is as a communication/presentation device with the role as a data storage/retrieval device coming in a close second. I guess computation device is probably in there somewhere around 3rd or 4th place taking turns with the computer as a control device. So most of the multicore discussion takes place within the confines of those four functions. But for right now we're into the problem solving thing and that is another story. Nope, we don't mean the computer as part of the solution to some problem. We mean using the computer to solve the problem. Nope we don't mean using the computer to execute step-by-step instructions that implement some known solution to a problem. We mean using the computer to find an unknown solution or hard to find solution to a problem. Yep! problem solving. We want our computer to put all of those processors to use for problem solving. And not just any kind of problems. We're fixated on AI-Complete problems. We are currently fantasizing about the possibilities of parallelism to the rescue. For the problems we're interested in the solutions are hidden among staggering almost astronomical numbers of possibilities and search, reasoning, and discrimination are at the very core of what we need the computer to do. We've been told that a single processor could never be fast enough to do what we need it to do. We are currently under a cruel ICOT spell being led to believe that somehow parallelism will help us reach the unreachable.
We really can't give you the silver-bullet-code approach we have in mind without first going a little deeper into the connection between AI-Complete problems, Search, and Parallelism. And right now Fallout 3 is calling and we have to spend a little time in Megaton. But we'll be back and we will make said connection clear.