Session 1: performance analysis

Abstract

he analysis of any hardware or software from the point of view of the actual and possible performance is crucial in the computer world. Huge efforts are made to create newer, better and faster computers and programs while minor design flaws can result in very low performance not even worth the invested money. Many scientists focus their research on the performance analysis of different areas like parallel programs, PC clusters, shared memory architectures, supercomputers, cache performance and so on. Basically, two approaches can be found in this effort. One group of researchers try to create analitical models to calculate the performance and limits “in theory” while the other group implements monitoring tools to collect as much data about real executions as they can and then process this data and find bottlenecks in the performance. The first session of the workshop deals with performance analysis issues of different areas in computer science. The performance of PC clusters is analysed here as well as parallel applications with the need of the power of a teraflop supercomputer. Simulator for low-level interconnection networks is presented as well as mathematical models for parallel programs. Every researcher aims at making possible to the users to improve the performance of their system and their applications. The first paper is “Beowulf Performance in CFD Multigrid Applications” authored by F. Tirado, C. Garcia, R.S. Montereo, M. Prieto and I.M. Llorente. Authors evaluated the performance of a Beowulf-class system from the viewpoint of Computational Fluid Dynamics applications. They used two multigrid solvers to test their PC cluster with different configurations. The results show that, not surprisingly, the best configuration depends on the target application. The second paper presents “SICOSYS: An Integrated Framework for studying Interconnection Network Performance in Multiprocessor Systems” written by V. Puente, J.A. Gregorio and R. Beivide. SICOSYS is a generalpurpose simulator that makes possible the analysis of the interconnection networks of multiprocessor systems. This simulator has been integrated into the RSIM shared-memory-architecture and processor simulator as well as into the SimOS simulator that also includes the effects of an operating system into the simulation. The third paper presents new ideas about “Performance Analysis for Teraflop Computers: A Distributed Automatic Approach” authored by M. Gerndt, A. Schmidt, M. Schulz and R. Wismuller. A new performance analysis system has been designed for the monitoring and analysis of extremely computationally intensive applications on a teraflop computer. In such environment, classical analysis techniques fail because they are not scalable for thousands of processors. This paper presents the design of a new, automatic performance tool that is scalable on teraflop computers using a distributed approach for the analysis process. The fourth paper is the “Execution Time Prediction for Parallel Data Processing Tasks” written by S. Juhasz. This paper presents a mathematical model for execution time prediction in the domain of parallel programs with moderate computational power needs but working on large amount of data. A parallel sorting application is then analysed as an example.