Which "rt" packages to choose for PREEMPT_RT functionality?

[mark whitney]

Hello,

I just got the latest 9.3 IoT kernel for my BeagleBone Black from the website.  The result when I do "uname -a" is:

Linux beaglebone 4.9.82-ti-r102 #1 SMP PREEMPT Thu Feb 22 01:15:12 UTC 2018 armv71 GNU/Linux

I did a sudo apt-get update followed by a sudo apt-get upgrade.  Now I'd like to install a kernel with PREEMPT_RT functionality.  When I do apt-cache search ti-rt or apt-cache search bone-rt I see a large number of matches (with many more ti-rt than bone-rt matches).

What's the difference between ti-rt and bone-rt packages?  In the past, I've tried both on BBBs and they both seemed to have PREEMPT_RT behavior in some simple latency tests (i.e. cyclictest).

Do I just have to update the linux-image package?  Or do I have to apply all "rt" updates for a given version number?

Finally, which version should I choose?  Should I just pick the newest that I see?  Or should I try to match it with the version in the "uname -a" shown above?  That's how I've tried to do things in the past.  But now I'm wondering if that's correct.

So in summary, I'd like to know how to pick a version, what additional "rt" packages I'll need, and whether to use "ti-rt" or "bone-rt" to get proper PREEMPT_RT behavior on BBB.

Thanks!