Contribution to a conference proceedings/Contribution to a book

FZJ-2025-02413

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Are Noise-Resilient Logical Timers Useful for Performance Analysis?

Corbin, G. (Corresponding author)FZJ* ; Daoud, N.FZJ* ; Mohr, B.FZJ* ; De Morais, G. ; Wolf, F.

2024
IEEE
ISBN: 979-8-3503-5554-3

This record in other databases:  

Please use a persistent id in citations: doi:10.1109/SCW63240.2024.00192

Abstract: In modern HPC systems, performance measurements are often disturbed by noise. Because repeating measurements to increase confidence in their results is costly, alternative noise-resilient techniques are desirable. Therefore, we implement alogical clock, which does not rely on real-time measurements, in Score-P. We explore several methods to model computational work with the clock increment, counting OpenMP loop iterations, LLVM basic blocks/statements, or hardware counters. We demonstrate the strengths and weaknesses of using logical time stamps in a trace analysis workflow with Score-P and Scalasca, by evaluating the performanceproblems we can find in three MPI+OpenMP mini-apps. By design, logical measurementsreliably show algorithmic issues, such as load imbalance, but cannot capture external aspects of program execution, for example memory contention. In summary, logical-time based measurements are a specialized but valuable addition to theperformance analyst’s toolbox.

---

Contributing Institute(s):

1. Jülich Supercomputing Center (JSC)

Research Program(s):

1. 5111 - Domain-Specific Simulation & Data Life Cycle Labs (SDLs) and Research Groups (POF4-511) (POF4-511)
2. DFG project G:(GEPRIS)449683531 - ExtraNoise – Leistungsanalyse von HPC-Anwendungen in verrauschten Umgebungen (449683531) (449683531)
3. ATMLPP - ATML Parallel Performance (ATMLPP) (ATMLPP)

---