Hi I am using SLES 11 sp3 with Realtime extension sp3(RT Kernel) .
I tried to run (as root) the rtcheck -v and got the following error:

RTCheck 0.7.6 - Linux Real-Time Environment Checker
RTCheck Initialization:
Locking all memory: ok
Setting up real-time scheduling: ok

System Tests:
Looking up boot_id (220ed37a-7284-4e5f-aede-34de40bfd35b): ok
Checking for out-of-tree RT extensions: failed
Kernel was not built with CONFIG_PREEMPT_RT=y
Checking for robust (PI) mutex support: ok
Testing for acceptable hrtimer resolution (<=100us): ok
Reporting 58us
Testing for acceptable clock resolution (<=200us): ok
Reporting 1ns
Caching results in /var/cache/rtcheck: ok

User Permission Tests:
Trying to lock memory: ok

Some tests failed, exiting with status: 8

It shows checking for out-of-tree RT extensions failed and the kernel was not built. I am sad that I couldn't find any guide which explains how to solve this problem.
Does anyone know how to set it properly to run RT on this OS?