RPI4 - Debian / LinuxCNC / EtherCAT / XFCE

rod, you should be able to mount the boot partition (FAT) and edit cmdline.txt and add isolcpus=2,3 to the end.  I don't think any recompile of the kernel is needed.

ftree wrote:

rod, you should be able to mount the boot partition (FAT) and edit cmdline.txt and add isolcpus=2,3 to the end.  I don't think any recompile of the kernel is needed.

Thanks for reminding me what I did! I had forgotten....

try running
latency-histogram --nobase --sbins 1000
before and after that change and see if you get an improvement. I'll do likewise. on x86 its a basic part of a lcnc install.

in fact i thought thougt i'd set this at first boot!

github.com/djsftree/rpi-img-builder/comm...0ddea94cbc22a5bddR33

You can check for core isolation by

sudo cat /sys/devices/system/cpu/isolated

the dev of the rpi-builder also have a neat tools to alter the governor / cpu speed

governor -h

-c Conservative
-o Ondemand
-p Performance

with isolcpus=3 and five glxgears.

+/- 60us, sd=6us

 

Looks great. Better than my production machines

Unfortunately, envolato's wheel is not compatable on our platform so it look like we need to compile vtk