VIRTUAL MEMORY PROTOCOL SEGMENTATION OFFLOADING

摘要

Methods and systems for a more efficient transmission of network traffic are provided. According to one embodiment, presence of outbound payload data, distributed across a first and second payload buffer, within a user memory space of a network device that has been generated by a user process is determined by a bus/memory interface or a network interface unit. The payload data is fetched by performing direct virtual memory addressing of the user memory space including mapping virtual addresses of the payload buffers to corresponding physical addresses, including: (i) when the payload buffers are noncontiguous, then retrieving the outbound payload data with reference to multiple buffer descriptors having starting virtual addresses of the payload buffers and (ii) when they are contiguous, then retrieving the outbound payload data with reference to a single buffer descriptor. The outbound payload data is then segmented across one or more TCP packets.

主权项

1. A method comprising:
responsive to storage of outbound payload data within a user memory space of a system memory of a network device generated by a user process running on a host processor of the network device, determining, by a bus/memory interface of the network device or a network interface unit of the network device, presence of the outbound payload data, wherein the outbound payload data is distributed across at least a first payload buffer and a second payload buffer within the user memory space; fetching, by the bus/memory interface on behalf of the network interface unit, the outbound payload data from the first payload buffer and the second payload buffer by performing direct virtual memory addressing of the user memory space including: when the first payload buffer and the second payload buffer are noncontiguous, then retrieving the outbound payload data with reference to:
a first buffer descriptor including information indicative of a first starting virtual address within the system memory of the first payload buffer containing therein a first portion of the outbound payload data; anda second buffer descriptor including information indicative of a second virtual starting address within the system memory of the second payload buffer containing therein a second portion of the outbound payload data; and when the first payload buffer and the second payload buffer are contiguous, then retrieving the outbound payload data with reference to a single buffer descriptor, including information indicative of the first starting virtual address; and segmenting, by a network processor of the network interface unit, the outbound payload data across one or more Transmission Control Protocol (TCP) packets.