Prospects for virtualization of high-performance x64 systems

Abstract

Prospects for applying virtualization technology in high-performance computations on the x64 systems are studied. Principal reasons for performance degradation when parallel programs are running in virtual environments are considered. The KVM/QEMU and Palacios virtualization systems are considered in detail, with the HPC Challenge and NAS Parallel Benchmarks used as benchmarks. A modern computing cluster built on the Infiniband high-speed interconnect is used in testing. The results of the study show that, in general, virtualization is reasonable for a wide class of high-performance applications. Fine tuning of the virtualization systems involved made it possible to reduce overheads from 10–60% to 1–5% on the majority of tests from the HPC Challenge and NAS Parallel Benchmarks suites. The main bottlenecks of virtualization systems are reduced performance of the memory system (which is critical only for a narrow class of problems), costs associated with hardware virtualization, and the increased noise caused by the host operating system and hypervisor. Noise can have a negative effect on performance and scalability of fine-grained applications (applications with frequent small-scale communications). The influence of noise significantly increases as the number of nodes in the system grows.