Link Pack Area (LPA)

It’s a common Virtual Storage Area.
It’s non-getmainable.
It’s built at IPL time by loading Load modules contained in SYS1.LPALIB and its concatenations.
There are 2 LPAs: one above “the line” (16MB) and the other below depending on the residence mode of the load module.
Because the Load modules are in the Common Area they are shared by all address spaces in the system.
Modules have to be re-entrant, ie, modules that can be executed concurrently by several tasks but which cannot be modified.
Modules in LPA reside in Virtual Storage.
By placing module data sets in LPA, you can obtain improved MVS system performance.
LPA consists of:
- PLPA – Pageable Link Pack Area (defined in SYS1.PARMLIB(LPALSTxx))
- FLPA – Fixed Link Pack Area (defined in SYS1.PARMLIB(IEAFIXxx))
- MLPA – Modified Link Pack Area (defined in SYS1.PARMLIB(IEALPAxx))