A Scalable Timestamp-Based Durable Software Transactional Memory

The emerging non-volatile memory(NVM) provides a lot of advantages, including byte-addressability, durability, large capacity and low energy consumption. However, it is difficult to perform concurrent programming on NVM, because users have to ensure not only the crash consistency but also the correctness of concurrency. In order to reduce the development difficulty, persistent transactional memory has been proposed, but most of the existing persistent transactional memory has poor scalability. Through testing, we find that the limiting factors of scalability are global logical clock and redundant NVM write operation. In order to eliminate the impact of these two factors on scalability: A thread logical clock method is proposed, which eliminates the problem of global logical clock centralization by allowing each thread to have an independent clock; a dual version method of cache line awareness is proposed, which maintains two versions of the data, and updates the two versions cyclically to ensure the crash consistency of the data, thereby eliminating redundant NVM write operations. And based on these two methods, a scalable durable transactional memory (SDTM) is implemented and fully tested. The results show that under YCSB workload, compared with DudeTM and PMDK, its performance is up to 2.8 times and 29 times higher, respectively.