Which type of process scheduling does Linux and window uses?

Answer 1

Linux has a number of schedulers available in its kernel, plus at least one scheduler available as a patch. But the default schedler is the Completely Fair Scheduler. Like most modern schedulers, it is pre-emptive, meaning that instead of the process deciding when to give up the CPU, the kernel decides for it when to give up the CPU. This keeps even the most uncooperative process from starving the other processes on the computer of CPU time. From what I understand of how CFS works: It keeps an eye on how much of an assigned quantum (length of time.) is actually spent on the CPU by a process and how much of the quantum is spent blocking (Keeping off the CPU to wait for I/O requests to complete, a process can't usually proceed and keep going without requested data. During the time a process is waiting for the hardware, other processes make use of the CPU.) The less time a process actually uses the CPU on its given quantum, the higher a priority it gets so that when the data from an I/O operation is complete the process can quickly execute to the next I/O request and block again. This keeps the CPU busy, but the system responsive to just about any event.

I don't know what sort of process scheduling is used on Windows. Windows, unlike Linux, is given a pretty heavy black box treatment when it comes to its users and a great deal about its kernel is not common knowledge. Presumably it is a pre-emptive, priority-based scheduler. Doubtful it's as efficient as CFS.

Answer 2

Windows uses the multilevel feedback queue scheduling algorithm. Linux uses completely fair scheduler algorithm. Unix uses round robin scheduling algorithm.