[LITMUS^RT] PREEMPT_RT and SteamOS

[Björn Brandenburg]

On 15 Dec 2013, at 02:23, Glenn Elliott <gelliott at cs.unc.edu> wrote:

> I wonder if we could do anything interesting by overriding PREEMPT_RT and schedule SteamOS games with Litmus?

That would indeed be an interesting workload for work targeting soft real-time systems. 

>  Is MPI still actively working on PREEMPT_RT support in Litmus?

Work on PREEMPT_RT support hasn’t commenced yet. I haven’t had time to do major development since rebasing the kernel last summer. Please feel free to take the lead on this.

However, it’s not clear how long the PREEMPT_RT patch is going to be around.

From: http://lwn.net/Articles/572740/	
> 
> The community contribution to the realtime patch set "amounts roughly to zero", he said. There is a fair amount of frustration on the team in always chasing mainline and being unable to stop realtime-unfriendly mainline features because the code is out of tree. In his mind, that should not continue past 2014; either a larger group steps up to work on the code or the project can be declared "finished", he said. "I could live with either outcome."
> 
> Gleixner said that he was trying to scare the audience a little bit with his proclamation, but it is clear he has nearly reached the end of his rope. While he would like to see the project continue—and prosper—he has real concerns about making the kinds of changes to the kernel that are required without a deeper and wider group to maintain it all. It seems that it is now up to those who use the realtime kernel to either step up or prepare for a future where the mainline kernel will have to serve their needs.

His stance is perhaps just a bit exaggerated to get interested parties to contribute (e.g., seems like Valve should have some resources it could throw behind PREEMPT_RT), but it’s an interesting development to watch.

Thanks,
Björn