is there a PREEMPT-realtime patch for stable kernel version 2.6.31.1 ??

Also, as I was reading the RT_PREEMPT_HOWTO at:

http://rt.wiki.kernel.org/index.php/Main_Page

I noticed that the image shown by this link:

http://www.pengutronix.de/images/rt-wiki/menuconfig3.PNG

is possibly outdated, I could not find

"Non-preemptible critical section latency timing" option when I did

make menuconfig.

I have built and booted many RT kernels over the years, but not in the last 6 months to a year. Somehow I am having trouble getting 2.6.31-rt11 to boot. (No doubt I have forgotten some important step, so I am doing things step by step per the wiki pages.)

Gautam