Compressed memory swap for QoS of virtualized embedded systems

Virtualization has recently drawn attraction in smart consumer electronics as a way of completely isolating the main applications, which are in charge of the primary functionality of a device, from untrusted third-party applications. In a virtualized embedded device, flexible memory management is required to run multiple VMs efficiently on resource-constrained hardware. This paper presents an in-memory compressed swap device (CSW) for the virtualized consumer electronics environment. It swaps out only the memory of third-party applications in response to memory pressure on the main applications, to ensure its quality of service. To this end, CSW collaborates with memory ballooning, which is a scheme for dynamic memory partitioning between VMs. By compressing the swapped out memory pages, CSW can effectively provide memory to the main applications while preserving the availability of thirdparty applications. We implemented our scheme in a Xenbased virtualized system that has limited resources similar to conventional consumer electronics devices. The evaluation results show that CSW successfully provides memory to the main VM with a reasonable cost, while the third-party applications are not killed.