FEAS: A full-time event aware scheduler for improving responsiveness

Liu, D., Cao, J. and Cao, J.

    Due to the advances in software and hardware support for virtualisation, virtualisation technology has been adapted for server consolidation and desktop virtualisation to save on capital and operating costs. The basic abstraction layer of software that virtualises hardware resources and manages the execution of virtual machines is called virtual machine monitor (VMM). A critical part of VMM is the CPU scheduler which slices and dispatches physical CPU time to virtual machines. Xen’s credit scheduler utilised blocked-to-boosted mechanism to achieve low latency on I/O intensive tasks. However, it suppresses event notifications for the guest domain that is not blocked. This may delays the response of a guest domain doing mixed workloads, as its virtual CPU is seldom blocked when processing CPU-intensive tasks. We enhance the credit scheduler by making it full-time aware of inter-domain events and physical interrupt request events. Our proposed scheduler not only improves the responsiveness of domains doing mixed workloads, but also minimises the possibly caused scheduling unfairness. The experimental evaluation demonstrates the benefits of our proposed scheduler.
Cite as: Liu, D., Cao, J. and Cao, J. (2012). FEAS: A full-time event aware scheduler for improving responsiveness. In Proc. Australasian Computer Science Conference (ACSC 2012) Melbourne, Australia. CRPIT, 122. Reynolds, M. and Thomas, B. Eds., ACS. 3-9
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