Measurement-based characterization of global memory and network contention, operating system and parallelisation overheads: case study on a shared-memory multiprocessor

Presents a characterization of (1) the global memory and interconnection network contention overhead, (2) the operating system overheads, and (3) the runtime system parallelization overheads for the Cedar shared-memory multiprocessor. The measurements were obtained using five representative compute-intensive, scientific, loop parallel applications from the Perfect Benchmark Suite. The overheads were measured for a range of Cedar configurations from 1 processor to the full 4-cluster/32-processor configuration, thus characterizing the effect of this scaling on the overheads. For the full 4-cluster Cedar, the operating system overhead was found to constitute 5-21%: of the total completion time of an application. The parallelization overhead accounts for 10-25% of the application, completion time and the overhead due to global memory and network contention contributes 8-21% of the application completion time