Event-based performance perturbation: A case study

Abstract

Determining the performance behavior of parallel computations requires some form of intrusive tracing measurement. The greater the need for detailed performance data, the more intrusion the measurement will cause. Recovering actual execution performance jfrom perturbed performance measurements using eventbased perturbation analysis is the topic of this paper. We show that the measurement and subsequent analysis of synchronization operations (particularly, advance and await) can produce, in practice, accurate approximations to actual performance behavior. We use as testcases three Lawrence Livermore loops that execute as parallel DOACROSS loops on an Alliant FX/80. The results of our experiments suggest that a systematic application of performance perturbation analysis techniques will allow more detailed, accurate instrumentation than traditionally believed possible.