Search for: All records

Abstract. Flash based solid state drives (SSDs) have established them- selves as a higher-performance alternative to hard disk drives in cloud and mobile environments. Nevertheless, SSDs remain a performance bot- tleneck of computer systems due to their high I/O access latency. A com- mon approach for improving the access latency is prefetching. Prefetch- ing predicts future block accesses and preloads them into main memory ahead of time. In this paper, we discuss the challenges of prefetching in SSDs, explain why prior approaches fail to achieve high accuracy, and present a neural network based prefetching approach that signi cantly outperforms the state-of the-art. To achieve high performance, we ad- dress the challenges of prefetching in very large sparse address spaces, as well as prefetching in a timely manner by predicting ahead of time. We collect I/O trace les from several real-world applications running on cloud servers and show that our proposed approach consistently outper- forms the existing stride prefetchers by up to 800 and prior prefetching approaches based on Markov chains by up to 8. Furthermore, we pro- pose an address mapping learning technique to demonstrate the applica- bility of our approach to previously unseen SSD workloads and perform a hyperparameter sensitivity study.