The Question is:
Why is Working Set value from $SHOW PROC/CONT different from
F$GETJPI(xxx,"WSSIZE") for the same process?
The Answer is :
This is a terminology issue. The F$GETJPI item WSSIZE is the working
set size - or, more precisely, the working set CAPACITY - the maximum
number of pages which could be contained in the current working set,
The field "Working Set" displayed by SHOW PROCESS/CONTINUOUS gives the
actual number of pages currently contained in the working set.
Typically this will be less than WSSIZE.
You can derive the figure displayed SHOW PROCESS/CONTINUOUS as the sum
of the F$GETJPI items PPGCNT and GPGCNT.