Tuesday, October 11, 2016 • 14:40 - 15:10

At the Mini-RT-Kernel Summit held in Prague in October of 2011 it was decided that we should create “stable releases” for the -rt patch set. The idea would be that new development would take place on the latest mainline kernel with the PREEMPT_RT patch being ported to it. The previous releases would go into a stable mode similar to that of the mainline stable releases. Only fixes will be backported to these kernels. These stable releases will be supported as long as their mainline counterparts are officially supported by kernel.org.

Five years later, we current have 8 actively supported stable releases!

As most development of the PREEMPT_RT patch is to fix issues with real-time in mainline, a lot of these “development” patches are also backported to older releases. What exactly gets backported is mainly chosen by the opinion of the three main developers, and there are no set rules to what those are.

I want to spend a few minutes discussing what I do to maintain a stable release, and then I want a discussion from those that use them. What versions are currently used? Can we stop supporting a version even though it's still supported in mainline? What can be changed with the process? etc.

All users of the stable releases.

Steven Rostedt is one of the original developers of the Real-Time patch, and started working on it back in 2004. He is now the maintainer of the Real-Time Kernel Stable releases. He works for Red Hat as one of the main engineers on their Real-Time team. He is the maintainer of ftrace (the official tracing tool of the Linux kernel), and is a co-maintainer of the Linux RT scheduler. He is very active with the Linux community and has given several talks around the world on the topics of Real-Time and Tracing.