Applicability of Transactional Memory to Modern Codes

In this paper we illustrate the features and study the applicability of transactional memory (TM) as an efficient and easy-to-use alternative for handling memory conflicts in multi-theaded physics simulations that use shared memory. The tool used for our preliminary analysis of this novel construct is IBM's freely available Software Transactional Memory (STM) system. Instead of attempting to apply it to a production grade simulation code, we developed a much simpler test code that exhibits most of the salient features of modern unstructured mesh algorithms, but without the complicated physical models. We apply STM to two frequently used algorithms in realistic multi-physics codes. Our computational experiments indicate a good fit between these application scenarios and the TM features.