• 中国计算机学会会刊
  • 中国科技核心期刊
  • 中文核心期刊

J4 ›› 2013, Vol. 35 ›› Issue (11): 42-47.

• 论文 • 上一篇    下一篇

非对称交叉开关优化与设计

王永庆1,王克非1,肖立权1,刘路1,庞征斌2   

  1. (1.国防科学技术大学计算机学院,湖南 长沙 410073;2.国防科学技术大学并行与分布处理重点实验室,湖南 长沙 410073)
  • 收稿日期:2013-08-11 修回日期:2013-10-15 出版日期:2013-11-25 发布日期:2013-11-25
  • 基金资助:

    国家863计划资助项目(2013AA014301,2012AA01A301)

ptimization and design of high radix asymmetric crossbar  

WANG Yongqing1,WANG Kefei1,XIAO Liquan1,LIU Lu1,PANG Zhengbin2   

  1. (1.School of Computer Science,National University of Defense Technology,Changsha 410073;
    2.PDL,National University of Defense Technology,Changsha 410073,China)
  • Received:2013-08-11 Revised:2013-10-15 Online:2013-11-25 Published:2013-11-25

摘要:

高阶路由器设计面临的主要挑战之一是队头阻塞。提出了一种有效缓解队头阻塞的高阶路由器组织结构OEASC。OEASC使用两种技术来解决队头阻塞,一是采用非对称交叉开关的交换结构ASC,N×N交叉开关可以使用N/m个小型的m×N交叉开关来实现,降低输入端口间发生冲突的概率;二是奇偶队列机制,高效地利用存储资源,降低输入端口内冲突的概率,从而获得很高的吞吐率。对异构交叉开关的吞吐率模型进行了理论分析和模拟验证,给出了OEASC交叉开关的逻辑结构和瓦片化微结构。模拟结果表明,OEASC基本消除了队头阻塞,在有限输入队列长度时吞吐率可以达到98.6%。与采用队列长度为16的ASC相比,吞吐率提高了7.9%,使用一半的缓冲区即可达到与ASC相近的性能。

关键词: 高阶路由器, 互连网络, 吞吐率, 队头阻塞

Abstract:

Head-of-line (HOL) blocking limits the throughput of high radix switches. An efficient architecture, OEASC, is proposed for highradix switches. This architecture takes advantages of two costeffective strategies for dealing with the HOL blocking problem. The first is referred to as asymmetric crossbar(ASC), through which a N×N switch can be formed by N/m smaller m×N asymmetric crossbars, and the second is oddeven queues scheme, through which the resources (mainly memory queues) of the switch can be used more efficiently. A tilebased microarchitecture of 32×32 high radix switch is proposed. Clock cycleaccurate simulation shows that the impact of HOL blocking is nearly all eliminated and the switch throughput can be as high as 98.6%. The proposed OE-ASC architecture shows up to 7.9% of throughput over ASC with buffer depth 16, and can achieve comparable performance with half buffers.

Key words: high radix router;interconnection network;throughput;headofline blocking