Editing Scheduling (computing) (section)

===={{Anchor|MEDIUM-TERM}}Medium-term scheduling====
The ''medium-term scheduler'' temporarily removes processes from main memory and places them in secondary memory (such as a [[hard disk drive]]) or vice versa, which is commonly referred to as ''swapping out'' or ''swapping in'' (also incorrectly as ''[[paging]] out'' or ''paging in'').  The medium-term scheduler may decide to swap out a process that has not been active for some time, a process that has a low priority, a process that is [[page fault]]ing frequently, or a process that is taking up a large amount of memory in order to free up main memory for other processes, swapping the process back in later when more memory is available, or when the process has been unblocked and is no longer waiting for a resource.

In many systems today (those that support mapping virtual address space to secondary storage other than the swap file), the medium-term scheduler may actually perform the role of the long-term scheduler, by treating binaries as ''swapped-out processes'' upon their execution.  In this way, when a segment of the binary is required it can be swapped in on demand, or ''lazy loaded'', also called [[demand paging]].