Real-Time "PREEMPT_RT" Work Down To Just 50 Patches Atop Linux 6.0-rc1

Following Sunday's release of Linux 6.0-rc1, yesterday saw the release of 6.0-rc1-rt1 as the set of patches for providing real-time kernel support atop the upstream code-base. There is just roughly 50 patches to go until the PREEMPT_RT functionality is mainlined!

Particularly since Intel acquired Linutronix back in February, there has been light at the end of the tunnel for getting the Linux real-time work upstreamed. Getting the PREEMPT_RT patches upstreamed has been very close with the end of July state being just two road-blocks left and could be enabled for v5.20 -- now known as v6.0. It didn't happen for the v6.0 merge window, but we are now down to just 50 out-of-tree patches remaining.

With Linux 5.19 the RT patch series consisted of 57 patches but thanks to getting some of the changes prepped in upstream 6.0, it's down to just 50 patches. Of the 50 patches, it's not too bad either as there are five patches for example that are rather trivial for just enabling real-time (RT) support in the Kconfig files for ARM / ARM64 / POWER / x86 / x86_64. There are also a handful of patches each specific to POWER and the i915 graphics driver code.

Real-time support on mainline Linux kernels is very near...

Those curious can see the current Linux 6.0 RT patches for the work that remains out-of-tree. Hopefully this real-time work will manage to cross the finish line later this year with Linux 6.1, which should be a very exciting milestone considering that will also likely be the kernel with MGLRU support for better performance and low-memory handling as well as hopefully being the kernel adding the initial Rust programming language infrastructure.

Real-time support on the mainline kernel should jive nicely with other recent kernel features too like run-time verification for safety critical systems, among other enhancements and hardware support additions emboldening Linux on embedded platforms.