Real-Time Support "PREEMPT_RT" For Linux Held Up Due To Lack Of Funding

While there was kernel talk of merging the PREEMPT_RT code in 2020 for this real-time functionality for the Linux kernel, among other times in the past that has yet to happen. These "RT" patches have long been maintained out-of-tree but it turns out that while in the past it was seemingly close for merging, that effort has stalled for lack of funding.

The PREEMPT_RT code is around 200 patches and has seen consistent out-of-tree updates for use on real-time systems. Those unfamiliar with the RT patches can see their rather dated Wiki and other past material.

What's new today is finally some clarity on the mainlining situation for the RT patches... During an ELISA (Enabling Linux In Safety Applications) presentation last month by well known kernel developer Thomas Gleixner of Linutronix and who has been heavily involved in the RT patches, he provided an overview of PREEMPT_RT.

Those interested in the RT work can see his slide deck.

The unfortunate status though is that the PREEMPT_RT development and maintenance is "currently stalled due to a funding gap" and that funding gap needs to be closed to ensure mainline integration of the patches. Thus until organizations step up for funding of the Linux RT work, it doesn't look like there will be much movement in the near-term for getting the RT patches upstream. Somewhat surprising though about the lack of funding for Linux real-time work, but with more embedded vendors now aware of the situation, hopefully this situation will be addressed... Then again, there are many other open-source funding gaps out there with the situation being all too common.