Hello Intel Wired LAN experts,
My time-sensitive user space application reads out
the hardware TX timestamp via poll() and recvmsg(MSG_ERRQUEUE).
On an Intel E810-XXVDA2 (for SFP), it takes roughly 700 microseconds
until the TX timestamp is available in user space (Linux 6.7.4).
This latency of 700 microseconds is far too high for my application.
For comparision, on an Intel X550 card (Twisted pair),
my application retrieves the TX timestamp in roughly 30 microseconds
which is acceptable.
The output of ethtool of the tested E810-XXVDA2:
# ethtool -i enp65s0f1np1
driver: ice
version: 6.7.4
firmware-version: 4.40 0x8001c96c 1.3534.0
expansion-rom-version:
bus-info: 0000:41:00.1
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: yes
#
When searching for a solution about this high latency TX timestamp read,
I found the following thread from 2022:
https://patchwork.ozlabs.org/project/intel-wired-lan/patch/[email protected]/#2963591
Is this patch already in the current Linux Kernel 6.7.4 or is it pending?
Can you recommend anything else in order to reduce
the TX timestamp read latency?
If you know a better place for this issue, please let me now!
Kind regards,
Martin
