lab6.md

preparation reading

Turtles on the wire: understanding how the OS uses the modern NIC : how os and NIC interact

Illustrated Guide to Monitoring and Tuning the Linux Networking Stack: Receiving Data

qemu-networking

Linux networking stack from the ground up, part 1 : on PCI init

Linux Network Receive Stack Monitoring and Tuning Deep Dive (Patrick Ladd, pdf):

lspci -nn

lab key points

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• PCI config & enable

  

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• memory-mapped I/O

  

• direct memory access

• transmit descriptor ring buffer (legacy mode)

  63            48 47   40 39   32 31   24 23   16 15             0
    +---------------------------------------------------------------+
    |                         Buffer address                        |
    +---------------+-------+-------+-------+-------+---------------+
    |    Special    |  CSS  | Status|  Cmd  |  CSO  |    Length     |
    +---------------+-------+-------+-------+-------+---------------+
  

  

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• receive descriptor ring buffer

  • Receive Address Registers (RAL and RAH)
  • attention to RDT
  

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• interrupt & poll

  

• lwip tcp/ip stack; web server

knowledge

• ethtool