public inbox for linux-rt-users@vger.kernel.org
 help / color / mirror / Atom feed
* Network latency on 5.4 and 5.10
@ 2021-05-20  7:36 Christoph Mathys
  2021-05-20  8:08 ` Christoph Mathys
                   ` (3 more replies)
  0 siblings, 4 replies; 8+ messages in thread
From: Christoph Mathys @ 2021-05-20  7:36 UTC (permalink / raw)
  To: linux-rt-users

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

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2021-05-31 17:05 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2021-05-20  7:36 Network latency on 5.4 and 5.10 Christoph Mathys
2021-05-20  8:08 ` Christoph Mathys
2021-05-20 13:35 ` Peter C. Wallace
2021-05-25 14:30 ` Christoph Mathys
2021-05-26  3:23   ` chensong_2000
2021-05-26  6:10     ` Christoph Mathys
2021-05-26  7:15       ` chensong_2000
2021-05-31 15:16 ` Christoph Mathys

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox