Maybe browsing around at osadl.org will reveal some infos. They are doing a lot with realtime, e.g. here is a bench from an OMAP system
https://www.osadl.org/Latency-plot-of-system-in-rack-2-slot.qa-latencyplot-r2s2.0.html
and also are offering a lot of other informations, e.g.
https://www.osadl.org/Single-View.111+M5f6c0e654c7.0.html
is worth to read.
It's unlikely that they use the PRUSS but maybe you can catch some other ideas there.
Regards,
Alexander