MSDD:一种结合重复数据删除技术的内存交换机制

MSDD: a Memory Swap Scheme with Data Deduplication

内存交换操作中频繁的外存访问是制约程序运行性能的一个重要因素.提出一种结合重复数据删除技术的内存交换机制MSDD(Memory Swap with Data Deduplication),通过删除交换页面中的重复页面减少换出操作,从而降低交换操作对程序运行性能的影响.针对交换操作延迟敏感和内存紧缺的特点,MSDD机制采用了改进的MD5算法计算页面的数字指纹以限制其计算时延,同时通过哈希表存储删冗元数据以在内存空间占用率与删冗元数据的检索速率两方面取得权衡.在四种典型应用程序上的实验测试结果表明,MSDD机制可以减少内存换出操作达36.73%,提高程序运行性能达15.0%.

Frequent access to external storage in memory swap operations significantly decreases the performance of applications. This paper presents a memory swap scheme with data deduplicaiton （ MSDD ）, Which decreases swapping out operations by deleting redun- dant pages to mitigate the effect incurred by the swap operations. Given that the swapping out operation is sensitive to the operation latency and the size of the available memory, MSDD uses the improved MD5 algorithm to efficiently calculate digital fingerprints of pages and stores deduplication metadata by employing the hash-table to balance the size of memory occupancy and the retrieval time of deduplication metadata. Experiments results on four typical applications show that MSDD decreases operations of memory swap out by 36.73% and improves the performance of applications by 15.0%.