HPC Performance Domains on Multi-core Processors with Virtualization

As the number of cores increases in multi-core processors, more applications execute at the same time. In this paper we present a simple and non-intrusive approach that guarantees performance isolation for High Performance Applications. This is achieved using virtualization by creating multiple virtual machines on the same processor, which can be seen as different Performance Domains. While previously this technique has been explored for increasing utilization, in this work we exploit it for improving performance of multiple co-executing applications. For the purpose of this work we have studied two different virtualization approaches: (i) conventional hosted virtualization and (ii) bare-metal virtualization. To study the feasibility of this technique, we analyze the performance of applications when executing within a virtual machine. The isolation properties provided by both virtualization methods offer performance predictability for the executed applications. Our experimental results show that the performance overhead of executing on a virtualized environment is not significant, with the bare-metal virtualization resulting in an overhead of only 3%. Most importantly, virtualization is able to eliminate in some cases the negative effects of co-execution interference, thus applications running on virtual machines may achieve a better performance than running natively on the system.