Committing conflicting transactions in an STM

Dependence-aware transactional memory (DATM) is a recently proposed model for increasing concurrency of memory transactions without complicating their interface. DATM manages dependences between conflicting, uncommitted transactions so that they commit safely. The contributions of this paper are twofold. First, we provide a safety proof for the dependence-aware model. This proof also shows that the DATM model accepts all concurrent interleavings that are conflict-serializable. Second, we describe the first application of dependence tracking to software transactional memory (STM) design and implementation. We compare our implementation with a state of the art STM, TL2 [5]. We use benchmarks from the STAMP [22] suite, quantifying how dependence tracking converts certain types of transactional conflicts into successful commits. On high contention workloads, DATM is able to take advantage of dependences to speed up execution by up to 4.8?.

• Type: Conference
• Year: 2009
• Where: PPOPP
• Authors: Hany E. Ramadan, Indrajit Roy, Maurice Herlihy, Emmett Witchel
• Keywords: Dependence Tracking, Dependence-aware Transactional Memory, Parallel Computing, PPOPP 2009, Software Transactional Memory