Is automatic "smart" process priority management worth it?

Question

I am working on a very large application that has multiple processes running simultaneously; at any given moment there are none or there is exactly one process interacting with the user. Would it be a good idea to temporarily increase the priority of the process with which the user is currently interacting?

As a second part of the same question, please provide real-world examples if possible. Did any common operating systems or applications decide to implement or specifically to not implement such a feature?

Answer 1

If I were to do anything of the sort, I would suggest doing the inverse of what you propose. ie, instead of promoting one processes priority, demote all the other ones in your application. This has the advantage of not adversely affecting anything else running on the system simultaneously.

Answer 2

MS Windows already does this MSDN doc for priority boosts

Various virtual machine apps - e.g. VMWare fusion and Parallels on OSX give the choice of raising the priory of the Mac process or the VM