High-Throughput Cuckoo Hashing Accelerator on FPGA Using One-Step BFS

Abstract

Cuckoo hashing [1] is an efficient hash method with high space occupancy. For improved latency and throughput of cuckoo hashing, FPGA is used to accelerate basic operations of the hash table based on cuckoo hashing recently. However, the frequent kick out and reinsert operations degrade the throughput of cuckoo hashing implementation on FPGAs, especially under high table occupancy. In this paper, we propose a cuckoo hashing accelerator on FPGAs that uses one-step BFS (breadth-first search) to reduce the number of reinsert operations when the table occupancy becomes high. The average throughput of the accelerator achieves 185 million requests per second (MRPS) when the table occupancy reaches 92% at 200MHz. And the throughput at 90% table occupancy is 30% higher than the work in [2].