Lightweight Embedded RDMA Software Stack for High-Speed Sensor Data Acquisition

Remote direct memory access（RDMA）technology is widely used in high-performance computing and intelligent computing scenarios that require high bandwidth and low latency transmission, offering significant advantages over traditional TCP/IP protocol stacks in terms of bandwidth, efficiency, and latency. It has gradually become an industry consensus for high-speed sensors to access computing networks through RDMA technology. However, deploying RDMA in this scenario faces challenges due to the limited resources of embedded sensor nodes, making it difficult to deploy traditional software stacks. We conduct research on lightweight techniques for embedded RDMA software stacks, proposing a lightweight RDMA connection establishment method based on reliable UDP and a lightweight RDMA driver based on reliable Ethernet under conditions without high-performance CPU or operating system. An ultra-lightweight RDMA software stack suitable for embedded sensor nodes is designed. The experimental results show that the lightweight RDMA software stack for embedded systems can reduce the connection establishment overhead by approximately 94% and the software driver overhead by 84% compared with the standard RDMA software stack. The embedded sensor nodes and standard nodes use RDMA technology to perform sensor data acquisition and reliable transmission through one-level switching, with a system bandwidth of up to 98.04 Gbps, end-to-end latency as low as 4.58 μs, and CPU overhead of standard nodes within the system as low as 4.2%. In terms of protocol compatibility, as the number of queue pairs and data volume increase, the READ and WRITE bandwidths of embedded RDMA nodes can reach the peak performance of standard nodes. Meanwhile, the READ and WRITE latency remains at the microsecond level when the data volume is small.