Block IO request handling for DRAM-SSD in linux systems

Abstract

This paper proposes a method to improve the performance of DRAM-SSD in Linux systems by modifying the block device driver. Currently, it processes requests in a segment-by-segment way. However it involves overheads because it needs to perform overlapped works repetitively when finishing one segment and starting next one. It prevents DRAM-SSD from running in full speed. The proposed method reduces the overheads by grouping multiple segments into one request, removing unnecessary duplicated steps. But, the grouping also involves overhead. Thus we propose to determine adaptively whether to do grouping or not according to the number of segments contained in requests. From the evaluation results, the throughput of the proposed method improved compared with the segment-by-segment way. © 2013 Springer Science+Business Media Dordrecht(Outside the USA).