Latency without CTPIO

Onload User Guide (UG1586)
Document ID
UG1586
Release Date
2023-07-31
Revision
1.2 English

The previous tests all use CTPIO. This test shows the result of disabling CTPIO, using UDP traffic with TCPDirect.

TCPDirect test applications can be found in:

onload-<version>/build/gnu_x86_64/tests/zf_apps/static

Run the zfudppingpong application on both systems:

[sys-1]# ZF_ATTR="interface=<interface>;ctpio=0" taskset -c 1 \
    zfudppingpong -s <payload> pong <sys-1_ip>:20000 <sys-2_ip>:20000
[sys-2]# ZF_ATTR="interface=<interface>;ctpio=0" taskset -c 1 \
    zfudppingpong -s <payload> ping <sys-2_ip>:20000 <sys-1_ip>:20000

where:

  • <interface> is the interface to use
  • <payload> is the payload size, in bytes
  • <sys-1_ip> is the IP address of sys-1
  • <sys-2_ip> is the IP address of sys-2.

The output identifies mean RTT, which is halved to give the mean ½ RTT latency.

Note: This can be compared with the result of the UDP test in TCPDirect Latency, which is identical except that CTPIO is enabled.