Will RT patches be merged in main line?

[Daniel.]

Hi everybody.

Does the RT patches have been merged in the main line? or, They will
be merged at all?

I found the RT wiki at
https://wiki.linuxfoundation.org/realtime/documentation/technical_details/start
but can't find if the patches were merged.

Also I have some questions about RT benefits/drawbacks:

The main benefit of RT kernel is that decreases the latency right?
I read that it make all parts of the kernel preemptive, is this right?
Why aren't these parts preemptive in the main line?
What is the impact of making these parts preemptive?

My general concept is that RT kernel has decreased latency, but
increased overhead, ... is this right?

Regards,

-- 
“If you're going to try, go all the way. Otherwise, don't even start. ..."
  Charles Bukowski