Changing real time attribs of a process not working


I’m trying to change the real time attribs of a process in Angstrom (on beaglebone) with chrt but it is not working:

chrt -p -f

returns always

chrt: failed to set pid 's policy: Operation not permitted

I’m logged in as root and set the real time limit to unlimited (ulimit -r unlimited).

Do I miss something?


Yes, it's in a cpuset cgroup, change the systemd unit to allow RT access by e.g. removing it from the 'cpu' cgroup

Thanks for your answer Koen!

Unfortunately, I’m not able to follow your instructions, what do you mean with “removing it from the ‘cpu’ cgroup”?
Do I have to modify a file in /sys/fs/cgroup/ ?