PREEMPT_RT Might Be Ready To Finally Land In Linux 5.20

[phoronix]

Phoronix: PREEMPT_RT Might Be Ready To Finally Land In Linux 5.20

After years in the works, the "PREEMPT_RT

https://www.phoronix.com/news/520-Maybe-Real-Time-PREEMPT_RT

[archkde]

When PREEMPT_RT lands in mainline, will it become possible to toggle to toggle real-time support using PREEMPT_DYNAMIC?

[rclark]

I don't need it/use it now, but would have been nice back when I was working with real-time Linux on the VME platform... Here is to hoping it will finally make it's way into the standard Kernel.

[timofonic]

Finally! Very good news! I really hope it gets all merged this time!

[coder]

Surely, legions of robots would be glad to have it!

[xorbe]

Any reason to NOT use preempt_rt?

[_ReD_]

The winter is coming! Actually preempt_rt may be good for desktop interactivity too.

[johncall]

Any reason to NOT use preempt_rt?

If pure speed is your ultimate goal, then a preemptable kernel is probably not what your looking for. These patches make workloads much more consistent/deterministic. One customer of mine wanted an RT kernel because they were managing traffic control signals in a large metro area. When the lights were instructed to change the flow of traffic, it was critical that the lights changed "on time" (avoiding the few occasions where it might actually take a long time --a second or two-- to act on the instruction.)

I like the latency chart on this page https://www.redhat.com/sysadmin/real-time-kernel

[caligula]

Any reason to NOT use preempt_rt?

Lower throughput

[Linuxxx]

When PREEMPT_RT lands in mainline, will it become possible to toggle to toggle real-time support using PREEMPT_DYNAMIC?

That is a good question!

And if yes, then how would it be named, because right now the kernel parameter "preempt=full" already toggles Linux into a soft-realtime kernel during boot.

Probably something like "preempt=rt"?

(And no, PREEMPT_RT will not improve your Linux gaming experience; most likely, quite the contrary because of drastically reduced throughput, or in other words lower FPS...)

["preempt=full" should already lower latencies & frame-time variance to a more than acceptable level!]