Setting rx_max_coalesced_frames to a specific value

Check that when rx_max_coalesced_frames is set to a specific value, Rx interrupts coalescing works accordingly.

  1. Establish connection between a pair of UDP sockets on IUT and Tester.

  2. Send a packet from Tester and receive it on IUT to be sure that IUT IP address is resolved.

  3. Disable use_adaptive_rx_coalesce on IUT interface.

  4. Set rx_coalesce_usecs to 0 for the IUT interface. Set rx_max_coalesced_frames to the value of coalesce_frames.

    • If setting fails with EOPNOTSUPP, try to set only rx_max_coalesced_frames, as setting rx_coalesce_usecs may be not available.

  5. Create a CSAP on Tester to capture packets sent from it to IUT.

  6. Create a CSAP on IUT to capture packets received from Tester.

  7. For some time send UDP packets from Tester to IUT, waiting a little after sending every packet. Receive and check data on IUT.

  8. Investigate timestamps of Tx packets captured by Tester CSAP. Memorize numbers of packets sent after big delays to ignore them when computing coalescing statistics on IUT.

  9. Investigate timestamps of packets captured by CSAP on IUT. Packets should be received in groups of coalesce_frames separated by larger delays.

Andrew Rybchenko andrew.rybchenko@oktetlabs.ru

Parameters:

env

Testing environment:

coalesce_frames

Value to set for rx_max_coalesced_frames:

  • 13

  • 100

  • 1000