TY  - CONF
AU  - Corbin, Gregor
AU  - Daoud, Nour
AU  - Mohr, Bernd
AU  - De Morais, Gustavo
AU  - Wolf, Felix
TI  - Are Noise-Resilient Logical Timers Useful for Performance Analysis?
PB  - IEEE
M1  - FZJ-2025-02413
SN  - 979-8-3503-5554-3
SP  - 1519 - 1530
PY  - 2024
AB  - 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.
T2  - SC24-W: Workshops of the International Conference for High Performance Computing, Networking, Storage and Analysis
CY  - 17 Nov 2024 - 22 Nov 2024, Atlanta (GA)
Y2  - 17 Nov 2024 - 22 Nov 2024
M2  - Atlanta, GA
LB  - PUB:(DE-HGF)8 ; PUB:(DE-HGF)7
UR  - <Go to ISI:>//WOS:001451792300156
DO  - DOI:10.1109/SCW63240.2024.00192
UR  - https://juser.fz-juelich.de/record/1041737
ER  -