Hi all!
I'm trying to upgrade from 4.9-rt to 5.4-rt (also tried 5.10). I'm
having a hard time getting networking to perform on the same level as
4.9 (latency wise). We drive an EtherCAT bus at 4kHz using the igb driver.
On 4.9, I just had to disable coalescing on the nic and increase the
priority of the irg threads and it performed as desired (more or less
according to [1] for 3.6+ without task pinning)
Doing the same on 5.4/5.10 does not seem to suffice any more. I get a
lot of warnings from our code that packets have not been sent or
received in time for the next control loop iteration.
Any suggestions on what I could try to improve the nic response?
Thanks!
Christoph
[1]
https://www.osadl.org/Real-time-Ethernet-UDP-worst-case-roun.qa-farm-rt-ethernet-udp-monitor+M514ebdffa90.0.html
