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PSWARM is a privilege that allows a process to control whether it can be swapped out of the balance set by executing the Set Process Swap Mode ($SETSWM) system service. A process must have this privilege to lock itself in the balance set (to disable swapping) or to unlock itself from the balance set (to enable swapping).

With this privilege, a process can create a process that is locked in the balance set (swap mode is disabled) by using an optional argument to the Create Process ($CREPRC) system service or, when the DCL command RUN is used to create a process, by using the /NOSWAPPING qualifier of the RUN command. Furthermore, a process can lock a page or range of pages in physical memory using the Lock Pages in Memory ($LCKPAG) system service.

This privilege should only be granted to users who need to lock a process in memory for performance reasons. Typically, this will be a real-time process. If unqualified processes have the unrestricted ability to lock processes in the balance set, physical memory can be held unnecessarily and thereby degrade system performance.