LOMARC: Lookahead Matchmaking for Multiresource Coscheduling on Hyperthreaded CPUs

Job scheduling typically focuses on the CPU with little work existing to include I/O or memory. Time-shared execution provides the chance to hide I/O and long-communication latencies though potentially creating a memory conflict. Hyperthreaded CPUs support coscheduling without any context switches and provide additional options for CPU-internal resource sharing. We present an approach that includes all possible resources into the schedule optimization and improves utilization by coscheduling two jobs if feasible. Our LOMARC approach partially reorders the queue by lookahead to increase the potential to find good matches. In simulations based on the workload model of Lublin and Feitelson, we have obtained improvements between 30 percent and 50 percent in both response times and relative bounded response times on hyperthreaded CPUs (i.e., cut times to two third or to half)