IEALPAxx (modified LPA list)

Start of change Use the IEALPAxx member to specify the reenterable modules that are to be added as a temporary extension to the pageable link pack area (PLPA). (The libraries, which contain the modules, must be cataloged in the system master catalog, unless the VOLUME parameter is specified.) This extension is temporary; the modules will remain in paging data sets and will be listed on the active LPA queue only for the duration of the IPL. End of change

The system will not automatically quick-start or warm-start these modules (that is, reinstate the modules without re-specification of the MLPA parameter). Both the modified LPA (MLPA) and the fixed LPA (FLPA) modules (those named in IEAFIXxx) do not require the system to search the LPA directory when one of the modules is requested. The modified LPA, unlike the fixed LPA, however, contains pageable modules that behave in most respects like PLPA modules.

Note:

A library that includes modules for the MLPA must be a PDS. You cannot use PDSEs in the LPALST concatenation.
The data sets in the LPALST can be a mixture of APF-authorized and non-APF-authorized data sets. However, any module in the modified link pack area will be treated by the system as though it came from an APF-authorized library. Ensure that you have properly protected any library that contributes modules to the modified link pack area to avoid system security and integrity exposures, just as you would protect any APF-authorized library.
If duplicate entries are found for a module or alias name, the first instance is used and subsequent instances are ignored.

You can use IEALPAxx to temporarily add or replace SVC or ERP routines. Another possible application would be the testing of replacement LPA modules that have been altered by PTFs.

LPA modules specified in IEALPAxx are placed in the MLPA or in the extended MLPA, depending on the RMODE of the modules. Modules with an RMODE of 24 are placed in the MLPA, while those with an RMODE of ANY are placed in the extended MLPA. By default, the MLPA and the extended MLPA are page protected, which means that a protection exception will occur if there is an attempt to store data into either area. To override page protection, use the NOPROT option on the MLPA system parameter.

LPA modules that have been replaced through IEALPAxx are not physically removed from the PLPA or from the LPA directory. They are, however, logically replaced because, when one of them is requested, MLPA is searched first and the system does not examine the LPA directory which contains the name of the replaced module.

The system searches the fixed LPA before the modified LPA for a particular module and selects the module from the modified LPA only if the module is not also in the fixed LPA.

If the first load module of a type 3 or 4 SVC routine is added or replaced, the SVC table is updated as required.