Nonvolatile main memory aware garbage collection in high-level language virtual machine

Abstract

Non-volatile memories (NVMs) such as Phase Change Memory (PCM) have been considered as promising candidates of next generation main memory for embedded systems due to their attractive features. These features include low power, high density, and better scalability. However, most existing NVMs suffer from two drawbacks, namely, limited write endurance and expensive write operation in terms of both time and energy. These problems are worsen when modern high-level languages employ virtual machine with garbage collector that generates a large amount of extra writes on non-volatile main memory. To tackle this challenge, this paper proposes three techniques: Living Objects Remapping (LORE), Dead Object Stamping (DOS), and Smart Wiping with Maximum Likelihood Estimation (SMILE) to reduce the unnecessary writes when garbage collector handles objects. The experimental results show that the proposed techniques not only significantly reduce the writes during each garbage collection cycle but also greatly improve the performance of virtual machine.