choosing an scheduling algorithm for a RTOS

Well that is an extremely open question - on which many PHDs have been written. I would suggest you turn it around, say what you are wanting to achieve and then let people suggest algorithms for your particular case.

However, I suspect this is just a student question - in which case I would suggest visiting Amazon.

--

Regards,
Richard.

+ http://www.FreeRTOS.org
Designed for Microcontrollers.  More than 7000 downloads per month.

+ http://www.SafeRTOS.com
Certified by TÜV as meeting the requirements for safety related systems.

I'm pretty sure this is a student question.

I've taught these classes before -- Operating Systems and Concurrent Programming, for example. And at my university, these are typically

2nd year classes for CS students. This framing of the question is almost right off of a homework sheet, which might be: "List four different scheduling algorithms with short descriptions about them," and in the next question, "For each of those, what factors would choose one scheduling algorithm over another?"

Jon

P.S. The only caveat to the OP's choice of words is the "RTOS" part of the question. Usually, classes like this don't focus on 'real-time' except in the broadest of senses, as the students have their hands full learning the methods themselves and some key issues about them and writing a simulator to try them out with some test cases. So about the level you get to in class is if the tasks get some reasonable percent of cpu time, a very low share of it, or no share at all -- under some scheduling method. I don't recall bandying "RTOS" around in class, except in broader strokes.