MemHole: An Efficient Black-Box Approach to Consolidate Memory in Virtualization Platform

As an important aspect of the hardware resource consolidation in virtualization environment, memory consolidation and over-commitment has been motivated by the increasing elastic computing cloud platform. The most popular consolidation technology, Memory Balloon, might introduce serious performance penalty with thrashing when guest memory usage changes dramatically. In order to overcome the drawback of Memory Balloon and guarantee the system performance, we propose Mem Hole, which provides more guest physical memory than really allocated and makes the corresponding host physical mapping undetermined until accessed, to reduce the thrashing of guest memory paging. The prototype of Mem Hole has been implemented in Xen platform and the efficiency has been shown in the preliminary evaluation.