11 10 PAG Trimming

LANSA Application Design

11.10 PAG Trimming

It is possible to trim the PAG being used in large online environments by pre-invoking the LANSA supplied system variable evaluation programs.

To invoke this facility place a call to M@SYSVAR and F@SYSVAR very early in the invocation stack. For example, a call during sign on to the IBM i may be considered. Such calls are extremely fast and do not occupy any significant PAG space. What is important is that the "early" or "pre-invocation" call ensures that the little PAG space they use is placed very early in the total PAG space, thus reducing PAG fragmentation when subsequent callers invoke either of these routines and then end.

To place a "pre-invocation" call to M@SYSVAR or F@SYSVAR simply use a normal CALL operation passing a character(1) parameter containing binary zeros (ie: X'00' in CL or *LOVAL in RPG/400)

To place a "close down" call to M@SYSVAR or F@SYSVAR simply use a normal CALL operation passing a character(1) parameter containing binary ones (ie: X'FF' in CL or *HIVAL in RPG/400)