The Computational Plant or Cplant is a commodity-based supercomputer under development at Sandia National Laboratories. This paper describes resource-allocation strategies to achieve processor locality in Cplant and other supercomputers. Users of Cplant and other Sandia supercomputers submit parallel jobs to a job queue. When a job is scheduled to run, it is assigned to a set of processors. To obtain maximum throughput, jobs should be allocated to localized clusters of processors to minimize communication costs and avoid bandwidth contention caused by overlappingjobs.
This paper introduces new allocation strategies and performance metrics based on space-filling curves and one dimensional allocation strategies. These algorithms are general and simple. Our preliminary results based on simulations and a Cplant implementation indicate that both space-filling curves and one-dimensional packing can improve processor locality. These new allocation strategies are implemented in the new release of the Cplant System Software, Version 2.0. This version is being phased into the Cplant systems at Sandia in April 2002.