RTLinUx下基于半轮询驱动的用户级报文传输机制

网络通信软件的处理开销已成为影响机群系统的性能瓶颈,为了提高机群系统的网络性能,在实时操作系统RTLinux下,设计并实现了一个符合VIA规范的用户级通信软件UMPS,提出了半轮询驱动的概念,利用半轮询驱动机制降低了系统中断频率,明显提高了短报文的处理能力.通过更为高效的地址翻译和基于资源映射图的缓冲区管理算法,应用程序旁路操作系统,依靠异步DMA直接与通信设备进行交互,有效地降低了网络通信的延迟与开销.通过性能的分析比较表明,UMPS接收64 byte与1500 byte的报文时吞吐量分别达到394 Mbps和895 Mbps,与现有的报文传输机制相比,UMPS的性能有了较为显著的提高.

User-Level Message Passing Mechanism Based on Semi-Polling Driven in RTLinux

Software overhead in interconnection network communication has currently become the bottleneck of a cluster system. To reduce it, a user-level communication software UMPS based on real-time OS RTLinux is designed and implemented, which is comfortable with VIA. A new concept of semi-polling driven is presented. With the semi-polling driven mechanism, the interrupts frequency is lowered and the processing performance for short message is significantly ameliorated. By means of the address translation and buffer managing algorithm based on the resource-mapping graph, applications bypass OS and interact with network interface directly using asynchronous DMA. So the overhead and latency in communication are efficiently reduced. Experimental results indicate that the throughputs of UMPS for 64 byte and 1500 byte messages are 394 Mbps and 895 Mbps respectively, and the performance of UMPS surpasses that of other mechanisms.