Optimizing Runtime Reconfiguration Decisions

Partially reconfigurable hardware accelerators enable the offloading of computative intensive tasks from software to hardware at runtime. Beside handling the technical aspects, finding a proper reconfiguration point in time is of great importance for the overall system performance. Determination of a suitable point of reconfiguration demands the evaluation of performance degradation during runtime reconfiguration and expected performance benefit after reconfiguration. Three different approaches to determine a proper point of reconfiguration are discussed. Delays and weighted transitions are used to reduce the number of reconfigurations while keeping system performance at a maximum. Evaluation is done with a simulation model of a runtime reconfigurable network coprocessor. Results show that the number of reconfigurations can be reduced by about 35% for a given application scenario. By optimizing runtime reconfiguration decisions, the overall system performance is even higher than compared to pure threshold based reconfiguration decision schemes.