Complete HOW-TO Linux Mint 18.1 32/64 RTAI or PREEMPT with RIP install or deb

That should be OK but I would disable ISOLCPUs it will just make things run slower

OK but that didn't install the version you just compiled, you may have installed the packages from the buildbot repository.
After debuild -uc -us you have to go to the directory above linuxcnc-dev where you will find the *.deb files you built.
You need to run dpkg -i the_name_of_linuxcnc_uspace_package_just_built
And dpkg -i the_name _of_the_linuxcnc_doc_package_just_built

Remember to change to the actual names of the deb packages. There does seem to be an omission in the original post regarding installing the just built debs. Debuild only builds the packages, it does not install them. Although it does mention installing the kernel deb packages by clicking on them.

I edited this post to show how to enable the source code repositories (in case you missed the previous post about it) forum.linuxcnc.org/9-installing-linuxcnc...deb?start=480#112467

Got a note from fellow CNCer here in Sweden to check /boot/config-4.8.11-rt7

# CONFIG_PREEMPT_RT_FULL is not set

I think I have to get this one sorted out first, but how?

Hmmm

I have Swedish menus so I assume it is Synaptic in my menus?
Have been in there and done that (maybe the first time I did Update-Cache)
but I have got that part of configuring uspace working.

tecno wrote: Got a note from fellow CNCer here in Sweden to check /boot/config-4.8.11-rt7

# CONFIG_PREEMPT_RT_FULL is not set

I think I have to get this one sorted out first, but how?

Recompiling now with above set correctly.

OK, now I think the PC is running with correct OS and no isolcpu with decent values, right?