Design And Implementation Of NIC Driver Supporting RDMA Under Windows

In recent years,in the context of the era of big data,data centers have become an important part of modern social infrastructure.In the work process of big data and cloud computing,various applications need to process large amounts of data quickly,and data interaction must be quickly responded.Therefore,data transmission in data centers,finance and other industries needs to be more efficient than general communication networks.Low,microsecond-level transmission delay.In the traditional TCP/IP network architecture,the processing delay and data transmission delay of the end-side kernel protocol stack cannot be solved,so it is gradually unable to meet the ultra-low delay requirements of the new generation of data center network workloads.Based on the above reasons,the research group independently developed a data acquisition card based on RDMA technology to solve the problem of delay in data transmission from end-to-end and end-to-end.This article will drive this RDMA data acquisition card under the Windows operating system.The development and adaptation of the program ensure efficient and stable data transmission.This article mainly carried out the following work:(1)The DMA transmission architecture in the driver is designed,the shared buffer mapping method is adopted to realize data sharing,and the complex RDMA instruction transmission is carried out through the descriptor method,which realizes zero copy and kernel bypass,and solves the problem of high speed.The problem of high latency of data transmission in the network.For multi-core processors and multi-queue network card devices,the method of binding related resources and processor cores is adopted to improve the cache hit rate of the CPU and avoid the overhead caused by thread synchronization.(2)Based on the RDMA specification,the instruction scheduling architecture at the control level and the data transmission scheme at the data level in the driver are designed.Through these designs,efficient control command transmission and data transmission can be completed,and the data transmission delay on the end side can be reduced.(3)The design of this driver is implemented under the framework of WDF driver.The driver program mainly includes two parts:user mode management driver and kernel mode hardware driver.As an interface to user programs,the user mode management driver is mainly used for the issuance of related instructions and the management of shared buffers and RDMA work queues.Work;kernel-mode hardware drivers are mainly used for interactions between user programs and hardware devices,as well as memory scheduling,initial configuration and other operations that require kernel-mode permissions.(4)A series of tests were carried out on the compiled driver program to ensure the various basic functions of the driver program,and the end-side data transmission delay of the driver program was tested,which verified the low delay of the data transmission design of the driver program.