Runtime decision of hardware or software execution on a heterogeneous reconfigurable platform

In this paper, we present a runtime optimization targeting the speedup of applications running on a reconfigurable platform supporting the MOLEN programming paradigm. More specifically, for functions that have an execution time dependent on parameters, we propose an online adaptive decision algorithm to determine if the gain of running that function in hardware outweighs the overhead of transferring the parameters, managing the start and stop of the execution and obtaining the result. Our approach is dynamic in the sense it does not rely on compile time information.The algorithm is applied on a real video codec for which a function is implemented in hardware and we show improvements as big as 24% percent can be obtained for the specific kernel. We also determine the overhead and execution time ranges in which this optimisation is usefull and what other factors can influence it.