A reference string sampling method with dynamically changing parameters

Wittneben proposed a technique which determines the structural characteristics of a program's memory referencing behavior based only on a sampling of the complete reference string. This method controls the cost of the measurement by adjusting the sampling rate while simultaneously attempting to determine accurately the referencing behavior as reflected in its working set measurements. Wittneben's method is controlled by parameters with statically determined values. The aim of this paper is to present a modified sampling method in which sampling parameters are updated dynamically according to the actual program referencing behavior. The updating process is controlled by the phase-transition structure of a program. Furthermore, working set measurements of the program are based on modified principles which take into account the most probable sources of errors made during the sampling process. Experiments conducted with synthetic and real reference strings seem to demonstrate the superiority of the modified method in comparison with the technique originally formulated by Wittneben.