116. Sample Application Tests: Quota and Water-mark

This document provides test plan for benchmarking of the Quota and Water-mark sample application. This is a simple example app featuring packet processing using Intel® Data Plane Development Kit (Intel® DPDK) that show-cases the use of a quota as the maximum number of packets enqueue/dequeue at a time and low and high water-marks to signal low and high ring usage respectively. Additionally, it shows how ring water-marks can be used to feedback congestion notifications to data producers by temporarily stopping processing overloaded rings and sending Ethernet flow control frames.

116.1. Prerequisites

2x Intel® 82599 (Niantic) NICs (2x 10GbE full duplex optical ports per NIC) plugged into the available PCIe Gen2 8-lane slots in two different configurations:

  1. card0 and card1 attached to socket0.
  2. card0 attached to socket0 and card1 to socket1.

116.2. Test cases

The idea behind the testing process is to send a fixed number of frames from the traffic generator to the DUT while these are being forwarded back by the app and measure some of statistics. Those configurable parameters exposed by the control app will be modified to see how these affect into the app’s performance.Functional test is only used for checking packet transfer flow with low watermark packets.

The statistics to be measured are explained below. A table will be presented showing all the different permutations.

  • Ring size

    • Size of the rings that interconnect two adjacent cores within the pipeline.

  • Quota

    • Value controls how many packets are being moved through the pipeline per en-queue and de-queue.

  • Low water-mark

    • Global threshold that will resume en-queuing on a ring once its usage goes below it.

  • High water-mark

    • Threshold that will stop en-queuing on rings for which the usage has it.

  • Frames sent

    • Number of frames sent from the traffic generator.

  • Frames received

    • Number of frames received on the traffic generator once they were forwarded back by the app.

  • Control flow frames received

    • Number of Control flow frames (PAUSE frame defined by the IEEE 802.3x standard) received on the traffic generator TX port.

  • Transmit rate (Mpps)

    • Rate of transmission. It is calculated dividing the number of sent packets over the time it took the traffic generator to send them.
    Ring size Quota Low water-mark High water-mark Frames sent Frames received Control flow frames received Transmit rate (Mpps)
    64 5 1 5 15000000      
    64 5 10 20 15000000      
    64 5 10 99 15000000      
    64 5 60 99 15000000      
    64 5 90 99 15000000      
    64 5 10 80 15000000      
    64 5 50 80 15000000      

116.3. Test Case 1: Quota and Water-mark one socket (functional)

Using No.1 card configuration.

This test case calls the application using cores and ports masks similar to the ones shown below.

  • Core mask 0xFF00
  • Port mask 0x280

This core mask will make use of eight physical cores within the same socket. The used ports belong to different NIC’s attached to the same socket.

Sample command:

./examples/quota_watermark/qw/build/qw -c 0xFF00 -n 4 -- -p 0x280

After boot up qw and qwctl, send IP packets by scapy with low watermark value. Command format:

sendp([Ether()/IP()/("X"*26)]*<low watermark value>, iface="<port name>")

Sample command:

sendp([Ether()/IP()/("X"*26)]*10, iface="p785p1")

116.4. Test Case 2: Quota and Water-mark one socket (performance)

This test case calls the application using cores and ports masks similar to the ones shown below.

  • Core mask 0xFF00
  • Port mask 0x280

This core mask will make use of eight physical cores within the same socket. The used ports belong to different NIC’s attached to the same socket.

Sample command:

./examples/quota_watermark/qw/build/qw -c 0xFF00 -n 4 -- -p 0x280

116.5. Test Case 3: Quota and Water-mark two sockets (performance)

This test case calls the application using a core and port mask similar to the ones shown below.

  • Core mask 0x0FF0
  • Port mask 0x202

This core mask will make use of eight physical cores; four within the first socket and four on the second one. The RX port will be attached to the first socket whereas the TX is to the second. This configuration will provoke the traffic going through the pipeline pass through the QPI channel.

Sample command:

./examples/quota_watermark/qw/build/qw -c 0x8180706 -n 4 -- -p 0x202