Skewed pipelining for parallel simulink simulations

Abstract

Modern automotive and aerospace embedded applications require very high-performance simulations that are able to produce new values every microsecond. Simulations must now rely on scalable performance of multi-core systems rather than faster clock frequencies. Novel parallelization techniques are needed to satisfy the industrial simulation demands that are essential for the development of safety-critical systems. Simulink formalism is the industrial de facto standard, but current state-of-the-art simulation and code generation techniques fail to fully exploit the parallelism in modern multi-core systems. However, closed-loop and dynamic system simulations are very difficult to parallelize because of the loop-carried dependencies. In this paper we introduce a novel skewed pipelining technique that overcomes these difficulties and allows loop-carried Simulink applications to be executed concurrently in multi-core systems. By delaying the forwarding of values for a few iterations, we can break some data dependencies and coarsen the granularity of programs. This improves the concurrency and reduces the high cost of inter-processor communication. Implementation studies to demonstrate the viability of our method on a commodity multi-core system with 2, 3, and 4 processors show a 1.72, 2.38, and 3.33 fold speedup over uniprocessor execution.