Deferred runtime pipelining for contentious multicore software transactions

DRP is a new concurrency control protocol for software transactional memory that achieves high throughput, even for skewed workloads that exhibit high contention. DRP builds on prior works that chop transactions into pieces to expose more concurrency opportunities, but unlike these works, DRP performs no static analyses and supports arbitrary workloads. DRP achieves a high degree of concurrency across most workloads and guarantees deadlock freedom, strict serializability, and opacity. We incorporate DRP into the software transactional objects library STO [18] and find that DRP improves STO’s throughput on several STAMP benchmarks by up to 3.6×. Additionally, an in-memory multicore database implemented with our modified variant of STO outperforms databases that use OCC or transaction chopping for concurrency control. Specifically, DRP achieves 6.6× higher throughput than OCC when contention is high. Compared to transaction chopping, DRP achieves 3.3× higher throughput when contention is medium or low. Furthermore, our implementation achieves comparable performance to OCC and transaction chopping at other contention levels.