Trace File Comparison with a Hierarchical Sequence Alignment Algorithm

Performance optimization, especially in the field of HPC, is an integral part of today's software development process. One powerful way of optimizing applications is to analyze their event traces. Yet, the comparison of traces of multiple application runs is cumbersome. The impact of optimizations in the source code or the usage of different compiler flags has to be tracked manually. The challenge is to automatically identify exactly those areas that changed in the large amount of trace data. We propose a novel solution that combines sequence alignment algorithms with call graph analysis to compare and highlight traces event-wise. Our approach is able to automatically detect differences by aligning event traces. Fine-grained execution time differences can be extracted and displayed in performance charts. The results of our implementation are presented and discussed.