PREEMPT_RT Might Be Ready To Finally Land In Linux 5.20

After years in the works, the "PREEMPT_RT" support for building a real-time Linux kernel might finally be mainlined for the upcoming Linux 5.20 cycle if the last few remaining bits are reviewed/signed-off on in time for next week's merge window.

The Linux real-time patch series has been getting smaller with time and quite close to crossing the finish line with just around 50 patches to be merged. This allows for building a real-time / fully preemptible kernel off the mainline code for embedded Linux systems.

For years there had been talk of PREEMPT_RT coming "soon" to mainline but ultimately didn't pan out. The Linux RT developers were held up by funding.

The change this year though was Intel acquiring Linutronix as the Linux consulting firm heavily involved in the PREEMPT_RT patches.

Now today the word is that PREEMPT_RT could be ready for Linux 5.20 if the last two blockers are sorted out this week. Sebastian Andrzej Siewior of Linutronix wrote on the kernel mailing list:

a polite ping for the series. This is one of two road blocks to get RT enabled in v5.20. I don't want to add any pressure just point out that I can't sit still for days since the end is near ;)

Sebastian

That patch series are two signal/ptrace related patches needed for the PREEMPT_RT series. We'll see over the next two weeks during the Linux 5.20 merge window if the PREEMPT_RT patches are all aligned to finally be merged and there are no last minute issues or objections from Linus Torvalds or other key participants.