104. Poll Mode Driver Tests

This document provides benchmark tests for the userland Ethernet Controller Poll Mode Driver (PMD). The userland PMD application runs the IO forwarding mode test which described in the PMD test plan document with different parameters for the configuration of NIC ports.

The core configuration description is:

  • 1C/1T: 1 Physical Core, 1 Logical Core per physical core (1 Hyperthread) eg: using core #2 (socket 0, 2nd physical core)
  • 1C/2T: 1 Physical Core, 2 Logical Cores per physical core (2 Hyperthreads) eg: using core #2 and #14 (socket 0, 2nd physical core, 2 Hyperthreads)
  • 2C/1T: 2 Physical Cores, 1 Logical Core per physical core eg: using core #2 and #4 (socket 0, 2nd and 3rd physical cores)

104.1. Prerequisites

Each of the 10Gb/25Gb/40Gb/100Gb Ethernet* ports of the DUT is directly connected in full-duplex to a different port of the peer traffic generator.

Using interactive commands, the traffic generator can be configured to send and receive in parallel, on a given set of ports.

The tool vtbwrun (included in Intel® VTune™ Performance Analyzer) will be used to monitor memory activities while running network benchmarks to check the number of Memory Partial Writes and the distribution of memory accesses among available Memory Channels. This will only be done on the userland application, as the tool requires a Linux environment to be running in order to be used.

If using vfio the kernel must be >= 3.6+ and VT-d must be enabled in bios.When using vfio, use the following commands to load the vfio driver and bind it to the device under test:

modprobe vfio
modprobe vfio-pci
usertools/dpdk-devbind.py --bind=vfio-pci device_bus_id

If using igb_uio:

modprobe uio
modprobe igb_uio
usertools/dpdk-devbind.py --bind=igb_uio device_bus_id
Case config::

For FVL40g, if test 16 Byte Descriptor, need to set the “CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC=y” in ./config/common_base and re-build DPDK.

For CVL25G, if test 16 Byte Descriptor, need to set the “CONFIG_RTE_LIBRTE_ICE_16BYTE_RX_DESC=y” in ./config/common_base and re-build DPDK.

104.2. Test Case: Packet Checking

  1. Start testpmd and start forwarding:

    ./testpmd -c 0xf0 -n 4 -- -i
    testpmd> start
    
  2. The tester sends packets with different sizes (64, 65, 128, 256, 512, 1024, 1280 and 1518 bytes) which will be forwarded by the DUT. The test checks if the packets are correctly forwarded and if both RX and TX packet sizes match by show port all stats

104.3. Test Case: Packet Checking in scalar mode

The linuxapp is started with the following parameters:

::
-c 0x6 -n 4 -w <devid>,scalar_enable=1 – -i –portmask=<portmask>

This test is applicable for Marvell devices. The tester sends 1 packet at a time with different sizes (64, 65, 128, 256, 512, 1024, 1280 and 1518 bytes), using scapy, which will be forwarded by the DUT. The test checks if the packets are correctly forwarded and if both RX and TX packet sizes match.

104.4. Test Case: Descriptors Checking

  1. Start testpmd with descriptor parameters:

    ./testpmd -c 0xf0 -n 4 -- -i--rxd={rxd} --txd={txd}
    
  2. The tester sends packets with different sizes (64, 65, 128, 256, 512, 1024, 1280 and 1518 bytes) for different values of rxd and txd (128,,256, 512, 1024, 2048 and 4096) The packets will be forwarded by the DUT. The test checks if the packets are correctly forwarded.

104.5. Test Case: Single Core Performance Benchmarking

Snice this case we focus on CPU single core performance, the network aggregated throughput must grater than single core performance, then the bottleneck will be the core. Below is an example setup topology for performance test, NIC (one or more) ports connect to Traffic Generator ports directly:

Dut Card 0 port 0 ---- Traffic Generator port 0
Dut Card 1 port 0 ---- Traffic Generator port 1
 ...
DUT Card n port 0 ---- Traffic Generator port n

In order to trigger the best performance of NIC, there will be specific setting, and the setting vary from NIC to NIC.

In order to get the best single core performance, Server configuration are required:

  • BIOS
    • CPU Power and Performance Policy <Performance>
    • CPU C-state Disabled
    • CPU P-state Disabled
    • Enhanced Intel® Speedstep® Tech
    • Disabled Turbo Boost Disabled
  • Grub
    • default_hugepagesz=1G hugepagesz=1G hugepages=8
    • isolcpus=1-21,28-48 nohz_full=1-21,28-48 rcu_nocbs=1-21,28-48
  • Other
    • Core and NIC should be in the same socket.

Test steps:

  1. Start testpmd and start io forwading:

    ./x86_64-native-linuxapp-gcc/app/testpmd -c 0x1800000000 -n 4 -- -i--portmask=0x3 -txd=2048 --rxd=2048 --txq=2 --rxq=2
    
  2. The tester send packets which will be forwarded by the DUT, record the perfromance numbers.

The throughput is measured for each of these combinations of different packet size (64, 65, 128, 256, 512, 1024, 1280 and 1518 bytes) and different value of rxd and txd(128,,256, 512, 1024, 2048 and 4096) The results are printed in the following table:

Frame Size TXD/RXD Throughput Rate Excepted Throughput
64        
128        
256        
512        
1024        
1280        
1518        

104.6. Test Case: Pmd RSS Performance

The RSS feature is designed to improve networking performance by load balancing the packets received from a NIC port to multiple NIC RX queues.

In order to get the best pmdrss performance, Server configuration are required:

  • BIOS
  • Intel Hyper-Threading Technology is ENABLED
  • Other: reference to ‘Test Case: Single Core Performance Benchmarking’

Run application using a core mask for the appropriate thread and core settings given in the following:

  Rx Ports Rx Queues Sockets/Cores/Threads
1 1 2 1S/1C/2T
2 2 2 1S/2C/1T
3 2 2 1S/4C/1T
4 2 2 1S/2C/2T
5 2 3 1S/3C/2T
6 2 3 1S/6C/1T

note: A queue can be handled by only one core, but one core can handle a couple of queues.

  1. Start testpmd and start io forwading with the above parameters. For example, 1S/1C/2T:

    ./x86_64-native-linuxapp-gcc/app/testpmd -c 0x2000000000000030000000 -n 4 -- -i \
    --portmask=0x3 --txd=512 --rxd=512 --burst=32 --txpt=36 --txht=0 --txwt=0 \
    --txfreet=32 --rxfreet=64 --txrst=32 --mbcache=128 --nb-cores=2 --rxq=2 --txq=2
    
# Send packet with frame size from 64bytes to 1518bytes with ixia traffic generator,

record the perfromance numbers:

Frame Size Rx ports S/C/T Throughput Linerate
64        
128        
256        
512        
1024        
1280        
1518        

The memory partial writes are measured with the vtbwrun application and printed in the following table::

Sampling Duration: 000000.00 micro-seconds
---       Logical Processor 0       ---||---       Logical Processor 1       ---
---------------------------------------||---------------------------------------
---   Intersocket QPI Utilization   ---||---   Intersocket QPI Utilization   ---
---------------------------------------||---------------------------------------
---      Reads (MB/s):         0.00 ---||---      Reads (MB/s):         0.00 ---
---      Writes(MB/s):         0.00 ---||---      Writes(MB/s):         0.00 ---
---------------------------------------||---------------------------------------
---  Memory Performance Monitoring  ---||---  Memory Performance Monitoring  ---
---------------------------------------||---------------------------------------
--- Mem Ch 0: #Ptl Wr:      0000.00 ---||--- Mem Ch 0: #Ptl Wr:         0.00 ---
--- Mem Ch 1: #Ptl Wr:      0000.00 ---||--- Mem Ch 1: Ptl Wr (MB/s):   0.00 ---
--- Mem Ch 2: #Ptl Wr:      0000.00 ---||--- Mem Ch 2: #Ptl Wr:         0.00 ---
--- ND0 Mem #Ptl Wr:        0000.00 ---||--- ND1 #Ptl Wr:               0.00 ---