Zheng Weibin1,Ding Huining2,Li Qinghai1,Zhang Deyun1
(1.School of Electronics and Information Engineering,Xi'an Jiaotong University,Xi'an 710049,China;2.Northwest Regional Network Centre of Cernet,Xi'an Jiaotong University, Xi'an 710049,China)
Abstract:The forwarding performance of the NAPI mode of SMP(symmetric multiprocessor)Linux running on Gigabit networks are studied by experiments and profiles. It is found that the scalability of SMP Linux is poor; Netfilter is the performance bottleneck; and the synchronization overhead and load imbalance among processors are the main causes that influence the performance of Linux. The static scheduling with "Interrupt Affinity "is adopted to balance the load among processors, and to reduce the cache misses due to scheduling. Two locks are eliminated in Netfilter to reduce the synchronization overhead. Experiments show our proposal can improve the performance and scalability of SMP Linux.
Keywords:Linux;symmetric multiprocessor;static scheduling