情報処理学会 第78回全国大会講演要旨

A number of small parallel applications run on a high-performance computing (HPC) system simultaneously. Job mapping becomes crucial to improve system utilization and user experience, because fragmentation of unused compute nodes could not be assigned for an incoming job with even a smaller size. Wireless supercomputers and datacenters with 60GHz radio or free-space optics (FSO) have been proposed so that a diverse　application workload can be better supported by changing network topologies by swapping the endpoints of wireless links. In this study we proposed the use of FSO links for the purpose of improving job mapping. We investigated various trade-offs of the number of wireless links, time overhead of wireless link reconfiguration, topology embedding and job　sizes. Our simulation results demonstrate that by directly reconnecting non-neighboring computing nodes, the full FSO interconnection networks can improve the system utilization for user jobs on a supercomputer and thus shorten the whole service time especially for dealing with dozens of intensively incoming jobs, regardless of workload or scheduling policy. Furthermore, we evaluated a constrained and reasonable more use of partial FSO links and confirmed that it can achieve shorter queuing length and time.