operations, by building
(virtual storage) for
Frequently, there can be a performance gain when
substituted for virtual
operating system such as as can be improved by specifying as resident as
many frequently used as functions (transient sutroutines.
for virtual machine-initiated
desired routine or data.
associated with virtual machine
instructions used by the virtual machine's
1. The virtual=real option removes the need
reference translation and paging before
specific virtual machine.
2. The virtual machine assist feature reduces the real supervisor
feature, see "Virtual Machine Assist Feature" later in this
section. For a list of processors on which the feature is
available, see the
real supervisor state
currently in real storage, they cause a paging exception
The addressing characteristics of programs executing in virtual
storage have a significant effect on the
experienced by that virtual
scattered storage reference tend to increase the paging load of a
particular virtual machine.
dependent upon each other should be located in the same page. Reference
tables, constants, and literals should also be located near the routines
that use them. Exception or error routines that are infrequently used
code, paging activity can be reduced, since the page, although referred
to, is never changed, and thus does not cause a write operation to the
paging device. The first copy of that page is written on the paging
device when that frame is needed for some other more active page.