Hi Sri,
I am trying to find detailed explanation of preemption option
in config. For desktop, server, and low-latency desktop. Can anyone
explain in what scenarios these are useful.
Free Electrons has a great presentation about real-time Linux [1]. They go into some detail on the specific options of the rt-preempt patches on page 26 of their slides [2]. The other slides of the presentation are obviously a great read as well. Also, if you are interested in learning about real-time and issues related to it (and not specifically the rt-preempt patches), I recommend checking out the ELC 2010 video of the talk "Real-Time Linux Failure" by Frank Rowand [3] as well as Mike Anderson's excellent talk "Using Interrupt Threads to Prioritize Interrupts" [3]. IIRC the latter goes into details of the rt-preempt patches and explains the issues and solutions involved quite well.
Hope this helps :-)