Effective Stack Wear Leveling for NVM

With the rapid growth of data processed by computer systems, nonvolatile memory (NVM), represented by phase change memory (PCM), is regarded as a promising next-generation storage technology as it offers superior advantages over DRAM. However, PCM suffers from a severe write durability problem, leading to an extremely short lifespan under the uneven write patterns of real-world programs. We observe that loops are one of the primary causes of uneven writes on the stack. To alleviate this problem, we present Loop2Recursion, a compiler-assisted stack wear leveling technique that automatically transforms loops into recursive functions. In addition, we propose several optimizations to reduce the stack sizes and instruction counts of the generated recursive functions, two schemes to limit recursion depth, and selective loop transformation for cache-enabled architectures. Experimental results demonstrate that Loop2Recursion outperforms state-of-the-art methods by significantly improving stack wear leveling with a greatly reduced performance overhead.