LinuxCNC and Linux and Ubuntu and PC and RPi ping issues with Mesa 7i96s

I ran my RPi 5 and 7i96s overnight and completed 40 million pings with zero errors.

sudo chrt 99 ping -i .001 10.10.10.10 -c 40000000

At the same time in the background, I ran Latency Histogram and two Glxgears. I have attached photos in case anybody is interested in seeing the results.

I’m not sure what to make of the maximum ping time of just over 10 ms.

It seems that "hardware-irq-coalesce-rx-usecs 0" has fixed the issues I was having (aside from the 10 ms issue) at least on RPi 5 * GB with LinuxCNC 2.9.2.

======================================

What is this "coalesce" thing?

Interrupt coalesce settings (access.redhat.com/documentation/en-us/re...ing_networking/index)

"By using interrupt coalescing, the system collects network packets and generates a single interrupt for multiple packets. This increases the amount of data sent to the kernel with one hardware interrupt, which reduces the interrupt load, and maximizes the throughput."

=====================================

My /etc/network/interfaces looks like this:

=============================

source /etc/network/interfaces.d/*

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
address 10.10.10.11
hardware-irq-coalesce-rx-usecs 0

===========================

Hello Have you been able to fix the problem in the meantime?I am also thinking about using a pi 5 + 7i96s as I now have a second PC which is apparently not suitable for Linux CNC. If you were able to fix the problem, what was the cause and are you satisfied so far?

Regards Erwin 

Yes it works perfectly. I would have to dig out the fix — it was suggested on the forum and the Pi5 setup has been flawless ever since.

Vielen Dank für die Rückmeldung
Welche Version hast du? 8gb?

I bought the version with the most memory. I figured that it was safer to spend a little extra and never run out of memory (which could be fatal).

RNZ wrote:

I ran my RPi 5 and 7i96s overnight and completed 40 million pings with zero errors.

sudo chrt 99 ping -i .001 10.10.10.10 -c 40000000

At the same time in the background, I ran Latency Histogram and two Glxgears. I have attached photos in case anybody is interested in seeing the results.

I’m not sure what to make of the maximum ping time of just over 10 ms.

It seems that "hardware-irq-coalesce-rx-usecs 0" has fixed the issues I was having (aside from the 10 ms issue) at least on RPi 5 * GB with LinuxCNC 2.9.2.

======================================

What is this "coalesce" thing?

Interrupt coalesce settings (access.redhat.com/documentation/en-us/re...ing_networking/index)

"By using interrupt coalescing, the system collects network packets and generates a single interrupt for multiple packets. This increases the amount of data sent to the kernel with one hardware interrupt, which reduces the interrupt load, and maximizes the throughput."

=====================================

My /etc/network/interfaces looks like this:

=============================

source /etc/network/interfaces.d/*

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
address 10.10.10.11
hardware-irq-coalesce-rx-usecs 0

===========================

Why are you running a base thread for a latency test when using mesa hardware ?

RNZ wrote:

I ran my RPi 5 and 7i96s overnight and completed 40 million pings with zero errors.

sudo chrt 99 ping -i .001 10.10.10.10 -c 40000000

At the same time in the background, I ran Latency Histogram and two Glxgears. I have attached photos in case anybody is interested in seeing the results.

I’m not sure what to make of the maximum ping time of just over 10 ms.

It seems that "hardware-irq-coalesce-rx-usecs 0" has fixed the issues I was having (aside from the 10 ms issue) at least on RPi 5 * GB with LinuxCNC 2.9.2.

======================================

What is this "coalesce" thing?

Interrupt coalesce settings (access.redhat.com/documentation/en-us/re...ing_networking/index)

"By using interrupt coalescing, the system collects network packets and generates a single interrupt for multiple packets. This increases the amount of data sent to the kernel with one hardware interrupt, which reduces the interrupt load, and maximizes the throughput."

=====================================

My /etc/network/interfaces looks like this:

=============================

source /etc/network/interfaces.d/*

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
address 10.10.10.11
hardware-irq-coalesce-rx-usecs 0

===========================
 

There's no need to test with a base thread when using Mesa hardware.

Even with 4GB ram you wont come close to running out of memory when using the Linuxcnc image.

The reason I was running that test was because packets were being lost between the raspberry pie and the Mesa board. I couldn’t figure out why. It was suggested to change a setting (I forget which one, but it is documented on The Forum) and after that there was zero packet loss.

I think the raspberry pie five and Mesa set up is really quite brilliant. It’s very compact, and boots up really fast. The only negative i have found is that it’s difficult to put an external Wi-Fi antenna on the pie. If the pie is inside a metal box, it won’t connect easily to a Wi-Fi router. You can get around this by using an external Wi-Fi dongle. Or move the excess point and pie closer together.

No need for a base thread with an external motion controller.
I run mine with a NVMe drive, yeah boot is really fast, I've been playing a around with custom hardware and hostmot2 firmware over SPI. ATM I'm working on a ethernet board to replace the SPI\EPP board that mates with the fpga board I'm using.

If you could add your Etherent mods to the thread linked below it would be great, trying to have a one stop place for all issues/suggestions and such.
forum.linuxcnc.org/9-installing-linuxcnc...official-images-only

Cheers
Rob