Find John Fast!!

The popular paradigm of the computer is a web client, and large chunks of the software development effort is connected to web development. But Tracey and I are still trapped with the notion of the computer as a problem solver, not as part of the solution but as a solver. We use the computer to solve hard problems and we currently are trying to solve unsolvable problems.

In both cases we are struggling with Level 1 parallelism (see Figure 1). We are pursing a suspicious possibly spurious connection between problem complexity, search, and Level 1 massive parallelism.

In Level 1 parallelism, we are concerned with the inherent complexity of the problem, not necessarily the complexity of some algorithm used to solve the problem (see Figure 1). This can be a tricky distinction. Through either poor choice or poor programming I could come up with an overly complex algorithm for a simple problem. For example, I could come up with a search strategy that took exponential time to search a list that is in alphabetical order. It is well known that there are solutions to the problem of searching a ordered list that require far less work than any exponential search strategy. Binary search is a case in point. Even a brute force from start to end of the list search only requires that we look at each item in the list once. So in Level 1 parallelism our focus is not on the complexity of some algorithm we might choose to solve the problem, but on the complexity of the problem itself.

For example, our problem is to obtain tomorrow's winning lottery number from John Smith who is currently on Main Street somewhere in the United States. The winning lottery number happens to be the same as a telephone number + a three-digit office extension on one of the business cards that he has in his possession. Unfortunately, John doesn't know that he has the winning lottery number. Of course many of the issues in this problem are obvious. Where in the U.S is John? Which city? Further, which Main Street in that city? East Main? West Main, etc.?

Not only do we have to find the city and the correct Main Street, we also have to find which John Smith. Perhaps there is more than one John Smith currently standing on some Main Street in the U.S. After we have tracked down John Smith, we've got to see what business cards he has in his possession and which ones have phone numbers with 3 digit extensions. And then if there is time to buy lottery tickets before tomorrow's drawing!

There are lots of strategies that we could use in trying to accomplish our goal. Each of those strategies have their own complexities. But we are more concerned with the inherent complexity of the problem itself. Although this problem suggest extremely obvious applications of parallelism (embarrassingly parallel in this case). Is massive parallelism sufficient? What if there are tens of thousands of John Smith's currently on Main Street somewhere in America? What if most of those John Smiths are salesman and have thousands of applicable business cards in their possession? How do we distinguish our John Smith that's currently on Main Street somewhere in America from all of the other people who are currently on Main Street somewhere in America? Can we obtain the winning lottery number from John Smith before tomorrow's lottery drawing? What level of parallelism would make that possible? How would that parallelism be structured or organized? How would the parallelism be managed?

Keep in mind that we've made no mention of computers. Level 1 analysis and decomposition happens before computer solutions are modeled. The paradigm shift requires not only rethinking parallel approaches but also rethinking our approaches to problem and solution modeling. But yet there is hope from the ghosts of ICOT and the Fifth Generation project. Stay tuned.

Real World Parallelism Webinar Series
  • November 17, 2009
    Visual Effects for Animation - presented by DreamWorks Animation
    Speaker: Ron Henderson (Bio)

    Ron Henderson manages the FX Tools group at DreamWorks Animation, where he is responsible for developing physical simulation and procedural modeling tools. These systems have been used for key visual effects in recent films such as Kung Fu Panda and Monsters vs. Aliens (March 2009).

    Prior to joining DreamWorks in 2002 he was a senior scientist at Caltech with a joint appointment to the Applied Math and Aeronautics departments, where he worked on efficient techniques for the direct numerical simulation of fluid turbulence.

    Abstract:
    In this webinar, Ron Henderson will show examples of visual effects, from hair and feathers to smoke and fire, from a variety of DreamWorks Animation feature films. He will discuss in general terms the kinds of techniques used to achieve particular visual effects. Finally, Henderson will show a detailed breakdown of the dam-breaking scene from Madagascar: Escape 2 Africa, demonstrating how different elements of key frame animation, simulation, and rendering are combined in a real production shot.

  • December 1, 2009
    A Quick and Easy Way to Parallelize a Legacy Codebase with Intel® Threading Building Blocks (TBBs)
    Speaker: Bernard Laberge, Avid, Senior Principal Engineer (Bio)

    Bernard Laberge is a senior principal engineer in the video editors division at Avid. During his seven years with the company he has been actively involved in the replacement of the legacy video processing engines used by Avid editors with a common hardware-abstracted, component-based video processing engine currently running on the CPU with SIMD optimized code, GPU, and dedicated hardware.

    Abstract:
    Learn how to overcome the limitations of a thread-based scheduler, including dealing with the absence of recursive parallelism support and the inefficient handling of unbalanced processing load. Bernard Laberge addresses how Avid resolved the expensive refactoring of their thread-based scheduler into a task-based solution by choosing Intel® Threading Building Blocks (TBBs). He explores how Avid was able to easily integrate the Intel TBBs into their video editor applications and more than 5 million lines of code.

  • December 15, 2009
    How to Use Intel® Parallel Studio to Streamline Code Development in a Multicore Environment
    Speaker: Matt Dunbar, Director for Performance Technology, SIMULIA (Bio)

    Matt Dunbar is the director for performance technology at SIMULIA. Since joining the company in 1993, he has worked on parallelization of the Abaqus suite of products, initially for shared memory architectures and more recently for distributed memory architectures. Dunbar has also been intimately involved in selecting both the hardware and software tools used in the development of the Abaqus product line.

    Abstract:
    Resolve elusive, costly multithreading errors quickly and efficiently with Intel® Parallel Studio. While many coding problems that lead to bugs in software applications are typically straightforward logic errors, errors in managing memory and in multithreading code can sometimes take weeks to months to diagnose and fix. Matt Dunbar explores how and why taking advantage of multicore processors through multithreaded code is critical for compute-intensive applications. While spotlighting his work on SIMULIA's Abaqus finite element solver, Dunbar addresses the need for multicore execution and shares his experiences using Intel Parallel Studio to streamline code development in a multicore environment.