Real-Time / PREEMPT_RT Support Should Finally Be Mainlined Soon In The Linux Kernel

In 2019 there were kernel developers talking at conferences that the remaining "PREEMPT_RT" patches for a real-time kernel should be mainlined in early 2020. That didn't happen for the long ongoing work around the "RT" patches while at this week's Linux Plumbers Conference (LPC 2020) is that the work should finally be close to merging to mainline.

At this week's virtual LPC 2020 is a real-time micro-conference that has been covering the remaining RT patches that have yet to be mainlined so that PREEMPT_RT can finally happen without the long out-of-tree patches. Besides working on getting the remaining patches merged, topics like testing / continuous integration of the real-time functionality, how to handle back-porting of RT fixes, and similar matters. The PREEMPT_RT functionality is about making the kernel more predictable and reducing latencies (maintaining low latency) of the kernel to cater to real-time workloads. This work has been going on for nearly two decades while finally there is light at the end of the tunnel for PREEMPT_RT in mainline.

The RT kernel patches have been going through some clean-ups recently. The developers don't appear to be planning to release RT patches for the now stable Linux 5.8 kernel but rather hoping to get some new patches out soon that will apply against Linux 5.9 and the latest mainline state. A "big flood of patches" should be showing up soon.

Those wishing to learn more about real-time Linux in general can see their Wiki site. If interested in all of the fine RT details from LPC 2020, see the micro-conference page. But long story short there is hope of finally having PREEMPT_RT completely mainlined in the very near future as we approach the end of 2020 or early 2021.