Since then Canonical has continued to provide this real-time (RT) kernel option to those part of the Ubuntu Advantage / Ubuntu Pro program but haven't really heard more from their RT kernel offering past that point.
A year later, Canonical is preparing to promote their real-time kernel to general availability (GA) status. Canonical tweeted out today that they are "soon approaching the general availability of Ubuntu with real-time kernel."
We are soon approaching the general availability of #Ubuntu with real-time kernel, so we’d like to invite you to our Introduction to real-time #Linux on-demand webinar happening tomorrow.
— Canonical Ltd (@Canonical) January 10, 2023
Save your seat on January 11, 2023 at 8:00 PM CET 👇 https://t.co/1ItjK7LR8f pic.twitter.com/nyRc8t2uEP
Even when the RT kernel reaches GA, it looks it will remain part of the Ubuntu Pro / Ubuntu Advantage portfolio, which is at least free for personal use.
Meanwhile the upstream RT patch series is almost over the finish line. One of the last known blockers still being tackled was around the console support, but hopefully this year the RT kernel support will be fully mainlined upstream and in turn making it much easier for Linux distributions to offer real-time kernel flavors. The out-of-tree RT patches haven't been updated since the end of November but for those interested can be found via linux-rt-devel.git if wanting to spin your own RT kernel.