E-pipeline: Elastic hardware/software pipelines on a many-core fabric

On-chip many-core systems are expected to be in common use in the future. A set of homogeneous processors in a many-core system can be used to implement multiple pipelines which execute simultaneously. Pipelines of processors use varying numbers of cores when their workloads vary at run time. In this paper, we show how such a system executing multiple pipelines with varying workloads can be implemented. We further show how the system can switch cores within a pipeline (intra-elasticity) and between pipelines (inter-elasticity). The method is named E-pipeline, and is implemented and evaluated in a commercial tool suite. Compared to reference design methods with clock gating, E-pipeline achieves the same power savings, maintains the throughput to meet throughput constraints and reduces core usage by an average of 37.7%. The adaptation overhead for switching cores is approximately 2μs.