Terry Wilmarth

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We present a performance prediction environment for large scale computers such as the Blue Gene machine. It consists of a parallel simulator, BigSim, for predicting performance of machines with a very large number of processors, and BigNetSim, which incorporates a pluggable module of a detailed contention-based network model. The simulators provide the(More)
Unstructured meshes are used in many engineering applications with irregular domains, from elastic deformation problems to crack propagation to fluid flow. Because of their complexity and dynamic behavior, the development of scalable parallel software for these applications is challenging. The Charm++ Parallel Framework for Unstructured Meshes allows one to(More)
Parallel discrete event simulation (PDES) of models with fine-grained computation remains a challenging problem. We explore the usage of POSE, our Parallel Object-oriented Simulation Environment, for application performance prediction on large parallel machines such as BlueGene. This study involves the simulation of communication at the packet level through(More)
Java 1 has emerged as a dominant language that could eventually replace C++. It is believed that using Java would boost programmer productivity because of its well-thought design, independence from backward-compatibility with C, absence of arbitrary pointers, etc. We present the design and implementation of a parallel extension to Java. The parallel(More)
Finite element simulations of dynamic fracture problems usually require very fine discretizations in the vicinity of the propagating stress waves and advancing crack fronts, while coarser meshes can be used in the remainder of the domain. This need for a constantly evolving discretization poses several challenges, especially when the simulation is performed(More)
Parallel discrete event simulations (PDES) encompass a broad range of analytical simulations. Their utility lies in their ability to model a system and provide information about its behavior in a timely manner. Current PDES methods provide limited performance improvements over sequential simulation. Many logical models for applications have fine granularity(More)
We describe our parallel 3-D surface and volume mesh modification strategy for large-scale simulation of physical systems with dynamically changing domain boundaries. Key components include an accurate, robust, and efficient surface propagation scheme, frequent mesh smoothing without topology changes, infrequent remeshing at regular intervals or when(More)
Parallel computers today are designed with larger number of processors than ever before, connected by large scale Interconnection Networks. Communication is the key to achieving high performance on such machines, making the study of Interconnection Networks important. Parallel simulations of Interconnection Networks present a unique problem characterized by(More)
Summary form only given. We present a performance modeling and programming environment for petaflops computers and the Blue Gene machine. It consists of a parallel simulator, BigSim, for predicting performance of machines with a very large number of processors, and BigNetSim, an ongoing effort to incorporate a pluggable module of a detailed contention-based(More)
Programming paradigms are designed to express algorithms elegantly and efficiently. There are many parallel programming paradigms, each suited to a certain class of problems. Selecting the best parallel programming paradigm for a problem minimizes programming effort and maximizes performance. Given the increasing complexity of parallel applications, no one(More)