Selective runtime monitoring: Non-intrusive elimination of high-frequency functions

High performance computing (HPC) systems are getting more and more powerful but also more and more complex. Supportive environments such as performance analysis tools are essential to assist developers in utilizing the computing resources of such complex systems. One of the most urgent challenges in event based performance analysis is the enormous amount of collected data. In particular, the recording of high-frequency short-running functions such as getter/setter class methods produces enormous amounts of data while in the same time contributing very less to an analysis of the overall application behavior. In this paper we address the impact of high-frequency function calls and present a method to minimize the amount of stored heavily-used functions while still keeping outliers that have an impact on the applications behavior. We propose a hierarchical memory buffer that is capable to discard recorded function calls when their duration is smaller than a pre-defined lower bound. We demonstrate the capabilities of our method with a prototype implementation that is based on the Open Trace Format 2, a state-of-the-art Open Source event trace library used by the performance analysis tools VAMPIR, SCALASCA, and TAU.