Enabling, but not configuring CONFIG_RT_GROUP_SCHED seems likely to be the cause of this: https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?h=master-next&id=9b039fc517876d312e7fa0955571101a299c91f5
Some discussion of this WRT lowlatency kernel is here: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1873315 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1875665 Title: rtkit-daemon[*]: Failed to make ourselves RT: Operation not permitted after upgrade to 20.04 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/rtkit/+bug/1875665/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs