Fixed Link Pack Area (FLPA)

  • It’s defined in SYS1.PARMLIB(IEAFIXxx).
  • It’s a non-pageale area of storage.
  • It’s loaded at IPL time from IEAFIXxx.
  • The data sets in its concatenation must be in the Master Catalog.
  • The Load modules must be kept in Fixed Storage Frames, ie, they cannot be paged out.
  • This area should be used only for Load modules that should not allow page faults because of integrity considerations.
  • Modules must be reenterant and refreshable.
  • The advantage of using the FLPA is the reduction in the Central Storage available for paging old jobs and starting new jobs.
  • Any library that includes modules for the FLPA must be a PDS. We cannot use PDS/Es in the LPALST concatenation.
  • Because Fixed modules are not paged, we can save I/O time and paging overhead by placing moderately used modules into FLPA.
  • The price for this performance improvement is the reduction in Storage available for paging old jobs and starting new jobs.
  • Modules with an RMODE of 24 are placed in the FLPA, while those with an RMODE of ANY are placed in the extended FLPA.

Content:

  • Load modules from LPALST concatenation, the LNKLST concatenation, SYS1.MIGLIB, and SYS1.SVCLIB can be included in the FLPA.

Notes:

  • Pages referenced frequently tend to remain in Central Storage even if they are not Fixed.

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