Hardware transactional memory with operating system support, HTMOS

Abstract

Hardware Transactional Memory (HTM) gives software developers the opportunity to write parallel programs more easily compared to any previous programming method, and yields better performance than most previous lock-based synchronizations. Current implementations of HTM perform very well with small transactions. But when a transaction overflows the cache, these implementations either abort the transaction as unsuitable for HTM, and let software takeover, or revert to some much more inefficient hash-like in-memory structure, usually located in the userspace. We present a fast, scalable solution that has virtually no limit on transaction size, has low transactional read and write overhead, works with physical addresses, and doesn't require any changes inside the cache subsystem. This paper presents an HTMOS - Operating System (OS) and Architecture modifications that leverage the existing OS Virtual Memory mechanisms, to support unbounded transaction sizes, and provide transaction execution speed that does not decrease when transaction grows. © 2008 Springer-Verlag Berlin Heidelberg.