Loop2Recursion: Compiler-Assisted Wear Leveling for Non-Volatile Memory

Abstract

Non-Volatile Memory (NVM) technologies, such as Phase Change Memory (PCM), herald the next generation of main memory as they offer superior features compared with DRAM. Unfortunately, NVM's limited write endurance hinders its adoption as its lifetime can be extremely short under skew writes. This paper observes that the loops in programs are one of the primary causes of uneven writes as they introduce the hot data and cause a large number of stack frames to be allocated to the same locations. To alleviate this problem, we present Loop2Recursion, a compile-time wear leveling technique for transforming loops into recursions automatically. Our approach is flexible as it can avoid a substantial memory overhead by limiting the depth of recursion. Experimental results demonstrate that Loop2Recursion can significantly improve the wear leveling over stack area compared to the state-of-the-art methods, while incurring only negligible performance overhead.