dpdk17

A major part of packet processing has to be done on a per-packet basis, such as switching and TCP/IP header processing. The overhead of the per-packet routines, however, exerts a significant impact on the performance of network processing. Generic Receive Offload (GRO) and Generic Segmentation Offload (GSO) are two effective techniques for mitigating the per-packet processing overhead by reducing the number of packets to be processed. Specifically, GRO merges the receiving packets of the same flow in RX, while GSO delays packet segmentation in TX.

In this talk, we introduce the design and implementation of GRO and GSO in DPDK. Our GRO design features a key-based reassembly algorithm to accelerate packet aggregation and provides two packet reassembly modes for different application scenarios. For the GSO library, a zero-copy based segmentation scheme is proposed to avoid the data movement overhead in packet segmentation. With intensive evaluations, our GRO and GSO library are capable of enhancing the packet processing throughput by up to 180% and 100%, respectively.