We have seen above several different schemes for processor scheduling. These can be distinguished by how they handle three orthogonal issues:
Do they support space scheduling or time scheduling?
Do they support dynamic or static partitions?
Do they coordinate or not with the applications when they reallocate processors?
The following table describes how the four policies we have seen handle these issues: l l l l. Time vs Space Static vs Dynamic Uncoord. vs Coord RRJob Time Static Uncoordinated Equipartition Space Quasi-Static Coordinated Process Control Space Quasi-Static Coordinated Dynamic Space Dynamic Coordinated
Equipartition and Process Control are not distinguished by this taxonomy because it does not distinguish between different coordination schemes. They are Quasi-Static since even though an application's need (number of VPs it creates) is static, its quota (number of unsuspended VPs) is dynamic and changes as applications are created/killed.
McCann et al evaluated these policies based on the following criteria:
Response Time
Fairness
Response Time to Short Jobs
Let us consider each in turn.