CMD: Classification-based Memory Deduplication through Page Access Characteristics

Limited main memory size is considered as one of the major bottlenecks in virtualization environments. Content-Based Page Sharing (CBPS) is an efficient memory deduplication technique to reduce server memory requirements, in which pages with same content are detected and shared into a sin-gle copy. As the widely used implementation of CBPS, Ker-nel Samepage Merging (KSM) maintains the whole mem-ory pages into two global comparison trees (a stable tree and an unstable tree). To detect page sharing opportunities, each candidate page needs to be compared with pages already in these two large global trees. However since the vast major-ity of pages have different content with it, it will result in massive futile page comparisons and thus heavy overhead. In this paper, we propose a lightweight page Classification