Blog Archives

The Woehr Room

Paradoxical Threading

Some threading semantics are desirably non-rigorous. What happens when we have to define every aspect of the parallel execution of our program?

Microsoft Parallel Computing Platform

David Callahan is a Microsoft Distinguished Engineer. Prior to Microsoft, David was at Tera Computer which in 2000 acquired and became Cray, Inc., where he worked on High Performance Computing (HPC). At Microsoft, David is a member of the Parallel Computing Platform team.

Parallel Impetus to Transform Computer Science

David Bader, Executive Director of High-Performance Computing at Georgia Tech, talks about parallel algorithms, hardware architectures for parallel programming, and the need for teaching parallelism as the norm in computer science.

Of Quarks and Practical Parallel Programming

In this conversation with Timothy G. Mattson, Senior Research Scientist Intel, Computational Software Lab, we find close agreement on the best approach to applying parallelism to business and general application programming. But first we discuss quantum physics.


Multicore Programming Summer School

The University of Illinois at Urbana-Champaign will be conducting a summer school about multicore programming June 22-26, 2009. I spoke with Marc Snir who is organizing the program. Prof. Snir is co-director of UIAC's Universal Parallel Computing Resource Center.

Getting Positioned in Parallel

As multicore issues arise in your personal programming practice, what you want to know is how to position yourself in the new arena. I have a few practical observations to share on this score.

Open Sourcer Explores Intel MulticoreTools on Windows, Barely Lives to Tell Tale

An inveterate open-sourcer, I'm making an uneasy peace with Microsoft Windows for the purpose of exploring the tools Intel has made available for parallelization of applications running on multicore platforms. I have used and verbally abused Windows in every release since Windows 2.1. Thus I am no stranger, but Windows has not been a C/C++ development environment for me since the 1990's, though I test and run my Java stuff on Windows.

So, d'oh, of course I'm looking for the simplest way to do this ... [article updated at end]

A == !A or What Happened to my App?

Most of us have read about the philosophers dining with insufficient chopsticks and the curved section of single-track railway in the mountain pass. These are the beginner examples of resource conflict and deadlock that serve as an introduction in comp sci texts to the challenges of parallel execution.

But they are coarse examples, and the world of multiprogramming today is very finely grained indeed.

Applications properly designed for multithreading on a single processor using all the approved locks and semaphors can still misbehave on multiple processors.

Graduating from Multitasking to Multiprogramming

For two decades, event-driven programming in multi-threaded environments created the cinematic illusion of parallel processing. Now that multicore chips have brought down the price of parallel processing to consumer levels, we are reminded that the programming practices which deliver efficiency in the multi-threaded emulation of parallelism are not genuine parallel algorithms.

Calendar

September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008

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.