Comparison of Preemption Schemes for Partially Reconfigurable FPGAs

Preemption techniques for hardware (HW) tasks have been studied in order to improve system responsiveness at the task level and improve utilization of the FPGA area. This letter presents a fair comparison of existing state-of-the-art preemption approaches from the point of view of their capabilities and limitations as well as impact on static and dynamic properties of the task. In comparison, we use a set of cryptographic, image, and audio processing HW tasks and perform tests on a common platform based on a Virtex-4 FPGA from Xilinx. Furthermore, we propose the preemption as a method which can effectively increase FPGA utilization in case of HW tasks used as CPU accelerators in systems with memory protection and virtualization.