Cache coherence tradeoffs in shared-memory MPSoCs

Mirko Loghi, Massimo Poncino, Luca Benini

Abstract: Shared memory is a common interprocessor communication paradigm for single-chip multiprocessor platforms. Snoop-based cache coherence is a very successful technique that provides a clean shared-memory programming abstraction in general-purpose chip multiprocessors, but there is no consensus on its usage in resource-constrained multiprocessor systems on chips (MPSoCs) for embedded applications. This work aims at providing a comparative energy and performance analysis of cache-coherence support schemes in MPSoCs. Thanks to the use of a complete multiprocessor simulation platform, which relies on accurate technology-homogeneous power models, we were able to explore different cache-coherent shared-memory communication schemes for a number of cache configurations and workloads.