%0 Conference Paper
%A Corbin, Gregor
%A Daoud, Nour
%A Mohr, Bernd
%A De Morais, Gustavo
%A Wolf, Felix
%T Are Noise-Resilient Logical Timers Useful for Performance Analysis?
%I IEEE
%M FZJ-2025-02413
%@ 979-8-3503-5554-3
%P 1519 - 1530
%D 2024
%X 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.
%B SC24-W: Workshops of the International Conference for High Performance Computing, Networking, Storage and Analysis
%C 17 Nov 2024 - 22 Nov 2024, Atlanta (GA)
Y2 17 Nov 2024 - 22 Nov 2024
M2 Atlanta, GA
%F PUB:(DE-HGF)8 ; PUB:(DE-HGF)7
%9 Contribution to a conference proceedingsContribution to a book
%U <Go to ISI:>//WOS:001451792300156
%R 10.1109/SCW63240.2024.00192
%U https://juser.fz-juelich.de/record/1041737