Transparent Near-Memory Computing with a Reconfigurable Processor

Data intensive applications like machine learning or big data analysis have stressed the requirements on memory subsystems. They involve computational kernels whose performance is not limited by the algorithmic complexity, but by the large amount of data they need to process. To counteract the growing gap between computing power and memory bandwidth, near-memory processing techniques have been addressed to improve the performance in such applications significantly. In this paper, we leverage a general purpose processor extended with a reconfigurable framework to execute hardware-accelerated instructions. This framework features a high-bandwidth memory interface to the nearest memory controller, allowing for greatly increased bandwidth compared to the standard system bus. We introduce region-based data processing, which allows to trigger operations by merely storing data and is especially suitable for large many-core designs. We show two different approaches to trigger the architecture for near-memory operations, one using interrupts for software-assisted processing and one directly interfacing with the hardware accelerator. Our evaluations show a performance gain of 72% on SAD kernels, with memory performance improved by 48%. Benchmarking AES encryption, we can show a speed up of 70%.