Installing LinuxCNC 2.9 or Master on Linux Mint 21

Todd wrote:

Just curios, does anyone know what the difference is between Rod's kernel and the broken Debian one? or in other words what the real problem is with the Debian one so we can suggest a proper fix for them?

Finally found the answer to this but it needs somebody with more experience than I do.

The Debian RT patches are here
salsa.debian.org/kernel-team/linux/-/tre...er/debian/patches-rt
The series file outlines the order of and whats going on
salsa.debian.org/kernel-team/linux/-/tre...er/debian/patches-rt
Support for lazy preemption seems a possible culprit.

This is a useful page
www.reddit.com/r/debian/comments/ai618b/...bian_kernel_patches/

Installed Mint 21.1 Running with no problems.
 

Hello ! Racing to get better latency results on j3355 - could other test latency histogram before and after stopping apparmor service ?

sudo systemctl stop apparmor
sudo systemctl disable apparmor ?

www.phoronix.com/news/AppArmor-Linux-5.5-72-Tests

One more:

exa.net.uk/latency-debugging/

I added apparmor=0 to the grub boot line and latency seemed to be a bit worse.
my 6.1 kernel, on an i5 with: isolcpus=2,3 nomodeset apparmor=0

 

Thank you ! It shows itself on a longer tests, especially with 0-100% cpu usage and changing programs. Left to run for night with some youtube - its ended at 17-20k. Now is 10-12k

forum.linuxcnc.org/18-computer/47825-latency-test#260814

Stanislavz wrote:

Thank you ! It shows itself on a longer tests, especially with 0-100% cpu usage and changing programs. Left to run for night with some youtube - its ended at 17-20k. Now is 10-12k

forum.linuxcnc.org/18-computer/47825-latency-test#260814

 I had a bit of a play and might stand corrected with:
quiet isolcpus=2,3 nohz_full=1 apparmor=0
my 6.1 kernel and 4 core i5
 
A lot of settings you have played with seem to be specific to a 2 core CPU

Could you try isolcpus=nohz,domain,2-3. Nohz is beeing set automatically on newer kernels with isolcpus.

3 hours of running... from youtube till 20 glxgears.

On settings - its more relevant on internal cpu driver.. cpu want to go green way and save power. That i have learned - monitor cpu voltage and C states. The real ones using i7z. Provided by cpufreq are configured, but not used.

Will give a shot to perf someday. But right now - 10wats tdp, onboard lpt freecad installed and running.

And in the morning.

That helped. Still needed apparmor=0
This is Debian Bookworm with my 6.1 kernel. 

So I think that will do me for now as its way under what a mesa card requires.
I really would like to poke around with the kernel parameters to see if there are settings that improve network latency (which you should be able to measure roughly with ping times. PCW has ping command syntax  that lets it run without a screen refresh until you stop it. Then look at averages...