Lightweight Messages: True Zero-Copy Communication for Commodity Gigabit Ethernet

摘要

Gigabit Ethernet has become the main cluster interconnection for its low price and well backward compatibility. But the communication performance through Gigabit Ethernet is quite disappointing due to its performance discre- pancies between the hardware and the communication software. To achieve over two-third physical bandwidth of a gigabit network interface, zero-copy protocol architecture is absolutely necessary. Unfortunately, it is impossible to realize true zero-copy communication over non re-programmable commodity Gigabit Ethernet adapters because the DMA engines cannot separate the protocol headers from the payload data directly. This paper introduces LM (Lightweight Messages), a true zero-copy communication mechanism which combines the application level fragmentation scheme with the driver level defragmentation scheme, for existing non-programmable Gigabit Ethernet adapters. Finally, experimental results show that LM can provide better performance than other lightweight communication approaches over commodity Gigabit Ethernet.