The limits of software transactional memory (STM): dissecting Haskell STM applications on a many-core environment.

In this paper, we present a Haskell Transactional Memory benchmark to provide a comprehensive application suite for the use of Software Transactional Memory (STM) researchers. We develop a framework to profile the execution of the benchmark applications and to collect detailed runtime data on their transactional behavior, running them on a 128-core multiprocessor. Using a composite of the collected raw data, we propose new transactional performance metrics. We analyze key statistics related to scalability, atomic sections, transactional events, overall transactional overhead and the relative hardware performance, accordingly drawing conclusions on the results. Our findings advance our comprehension on the STM runtime and the characteristics of different applications under the transactional management of the pure, functional programming language, Haskell.