BRU: Bandwidth Regulation Unit for Real-Time Multicore Processors

Poor time-predictability of the multicore processors is a well-known issue that hinders their adoption in the real-time systems due to contention in the shared memory resources. In this paper, we present the Bandwidth Regulation Unit (BRU), a drop-in hardware module that enables per-core memory bandwidth regulation at fine-grained time intervals. Additionally, BRU has the ability to regulate the memory access bandwidth of multiple cores collectively to improve bandwidth utilization. Besides eliminating the overhead of software regulation methods, our evaluation results using SD-VBS and synthetic benchmarks show that BRU improves time-predictability of real-time tasks, while it lets the best-effort tasks to better utilize the memory system bandwidth. In addition, we have synthesized our design for a 7nm technology node and show that the chip area overhead of BRU is negligible.