Intra- and inter-processor hybrid performance modeling for MPSoC architectures

The heterogeneity of modern MPSoC architectures, coupled with the increasing complexity of the applications mapped onto them has recently led to a lot of interest in hybrid performance modeling techniques. Here, the idea is to apply different modeling and analysis techniques to different subsystems/components of an architecture/application. Such hybrid techniques often turn out to be more efficient and accurate compared to relying on a single analysis technique for the entire system. However, the challenge associated with this approach is to combine the different analysis results effectively to obtain conservative performance estimates for the entire system. In this paper we study a hybrid scheme where certain system components are simulated (e.g. using instruction set simulators), whereas others are analyzed using a formal technique called Real-Time Calculus (RTC). The main novelty of our approach stems from our use of this hybrid technique even for multiple tasks mapped onto a single processing element. In contrast to this, previous approaches relied on either full simulation or RTC-based analysis for an entire architectural component (e.g. a processor or a bus). The techniques we develop in this paper therefore allow for both intra- and inter-processor hybrid performance modeling and show how the different analysis results can be combined to efficiently obtain tight performance estimates for complex MPSoC architectures. We demonstrate the usefulness of this approach using an MPEG-2 decoder application that is partitioned and mapped onto two processing elements connected by FIFO buffers.