Process Scheduling is not "Process" Scheduling - Should I disclose it to students? I have been teaching Operating Systems basics in a class and after Processes, Child Processes and Threads, we have managed to move to "Process Scheduling" 

Now, ironically, as we know that it is not the Process which is scheduled, but the threads precisely (we are following Linux Ubuntu there).

Here is what Silberchatz book (by the way, the title of the chapter is also "Process Scheduling") says about it:


  In Chapter 4, we introduced threads to the process model. On operating
  systems that support them., it is kernel-level threads-not processes-that are
  in fact being scheduled by the operating system. However, the terms process
  scheduling and thread scheduling are often used interchangeably.


(Silberschatz, Operating System Concepts, 8th Edition)

Although, I have taught them the respective algorithms; should I bring this discussion within the class and press the panic button by telling that its not the Processes which are scheduled but Threads? This question has been in my mind since long time and I couldn't look for a better place to get an answer than here.
Perhaps I'm just naive, but I don't see a dilemma here. Yes, teach them the current state of the art if that is appropriate in your course. Teach them some important historical precedents at some appropriate level of detail. In this case you shouldn't be teaching one edition of a book or one version of a particular OS. If the students are to have a future in the field they will still be working in 30-40 or more years. What they need is the background and skill to keep up with technological changes as they occur. 

You already say that you teach them the various scheduling algorithms for associating a software element with hardware. That is more essential than the specific granularity of the elements on either side of the equation. Even the standards of what constitutes efficiency may change over time. Teach them the principles, for which some blend of the old and the new is likely required. This will serve them well in matters other than Operating Systems proper. 

You should also look at a more recent edition of your text and at other books. This will help you get a handle on what the authors currently consider to be important. Tannenbaum, for example, would be a good supplement to Silberschatz et al.