rdisp/PG_MAXFS is a SAP Parameter attribute which is used to control Maximum size of SAP paging file information. This is available within R/3 SAP systems depending on the version and release level.
Below is the standard documentation available and a few details of the attributes values .
This value specifies the size of the SAP paging file in 8 KB blocks. The
paging file functions as memory for extracts and exports to memory. Aim:
The paging file must be sufficiently large. It is not a problem if it is
set to too large a size.
See SAP Parameter Documentation for full SAP documentation for this profile parameter.