Speaker: Ahmad Tarraf,  Technical University of Darmstadt, Laboratory for Parallel Programming

Title: Conquering Noise With Hardware Counters on HPC Systems

Date and time: Tuesday, April 18, 2 p.m. – 3 p.m.

Abstract:

With increasing system performance and complexity, it is becoming increasingly crucial to examine the scaling behavior of an application and thus determine performance bottlenecks at early stages. Unfortunately, modeling this trend is a challenging task in the presence of noise, as the measurements can become irreproducible and misleading, thus resulting in strong deviations from the actual behavior. While noise impacts the application runtime, it has little to no effect on some hardware counters like floating-point operations. However, selecting the appropriate counters for performance modeling demands some investigation. In this paper, we perform a noise analysis on various hardware counters. Using our noise generator, we add additional noise on top of the system noise to inspect the counters’ variability. We perform the analysis on five systems with three applications in the presence of various noise patterns and categorize the counters across the systems according to their noise resilience.

Short bio:

Ahmad Tarraf has been working since 2021 as a postdoc at the Technical University of Darmstadt in the laboratory for parallel programming. Dr. Tarraf received his B.Sc. degree in Mechatronics Engineering from RHU Lebanon in 2013 and his M.Sc.degree in Mechatronics Engineering with the specialization simulation and control in 2016 from the Technical University of Darmstadt. From 2017, he was a research assistant at the Institute of Computer Science at the University of Frankfurt in the research field formal abstraction and verification of analog mixed circuits. He later received his doctoral degree (Dr. rer. nat.) Magna Cum Laude in Computer Science from the University of Frankfurt in early 2021. His research interest includes High-performance computing, efficient file and storage systems, behavioral modeling, machine learning, formal verification, symbolic analysis, analog mixed-signal design, cybernetics, and robotics. Dr. Tarraf has been involved in several national research projects and is currently involved in the two EuroHPC projects ADMIRE and DEEP-SEA.

For a list of past and upcoming NHR PerfLab seminar events, see: https://hpc.fau.de/research/nhr-perflab-seminar-series/