SENDING PACKETS USING OPTIMIZED PIO WRITE SEQUENCES WITHOUT SFENCES

摘要

Method and apparatus for sending packets using optimized PIO write sequences without sfences. Sequences of Programmed Input/Output (PIO) write instructions to write packet data to a PIO send memory are received at a processor supporting out of order execution. The PIO write instructions are received in an original order and executed out of order, with each PIO write instruction writing a store unit of data to a store buffer or a store block of data to the store buffer. Logic is provided for the store buffer to detect when store blocks are filled, resulting in the data in those store blocks being drained via PCIe posted writes that are written to send blocks in the PIO send memory at addresses defined by the PIO write instructions. Logic is employed for detecting the fill size of packets and when a packet's send blocks have been filled, enabling the packet data to be eligible for egress.

主权项

1. A method comprising:
receiving sequences of Programmed Input/Output (PIO) write instructions to write packet data for respective packets stored in memory to a PIO send memory on a network adaptor; executing the sequences of PIO write instructions as an instruction thread on a processor that supports out of order execution, wherein execution of PIO write instructions cause data to be written to store units in a store buffer, the store units grouped into store blocks comprising a line of store units; wherein a portion of the PIO write instructions are executed out of order resulting in data being written to store units in different store blocks prior to the store blocks being filled; detecting when store blocks are filled; and in response to detecting a store block is filled, draining the data in the store block via a posted write to a buffer in the PIO send memory.