Compressed Memory Swap for QoS of Virtualized Embedded Systems

Abstract

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 third-party applications. We implemented our scheme in a Xen-based 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.(1)