The European Conference on Object-Oriented Programming (ECOOP), July, 2008
PDFMulti-tasking, managed runtime environments (MREs) for modern type-safe, object-oriented programming languages enable isolated, concurrent execution of multiple applications within a single operating system process. Multi-tasking MREs can potentially extract high-performance on desktop and hand-held systems through aggressive sharing of classes and compiled code, and by exploiting high-level dynamic program information.
We investigate the performance of a state-of-the-art multi-taking MRE for concurrent program execution. We find that due to limited support for multi-tasking and performance isolation in the memory management subsystem, multi-tasking performs poorly compared to a production-quality, single-tasking MRE. We present MTM²: a comprehensive memory management system for concurrent multi-tasking. MTM² facilitates performance isolation and efficient heap space usage through on-demand allocation of application-private regions. MTM² mitigates fragmentation using a novel hybrid garbage collector that combines mark-sweep with opportunistic copying. Our evaluation shows that MTM² improves overall performance, scalability, and footprint for concurrent workloads over state-of-the-art, multi- and single-tasking MREs.