Apr il 1 f 1981 100.2 IBM System Programmer's Guide
interval timer at virtual location
while the virtual machine is in control of the real processor. This
results in an update frequency of approximately
the same as for the real interval timer. Procedures that use the
virtual interval timer for jot accounting, performance measurements, and
the like, will therefore generate more accurate and repeatable time data
than they would if the virtual timer was being updated by CP routines.
levels: the
At the
system is loaded. The class A command:
set cpassist off
will disable both
class A com ma nd :
set sassist off
disables only the expanded virtual machine assist part of
as the virtual machine assist.
is truly independent.
At the virtual machine level, whenever
both expanded virtual machine assist and virtual interval timer assist
are automatically
command:
set assist off
both assists as well as the existing virtual machine assist are
disabled. If you issue:
set assist notmr
only the virtual interval timer assist is disabled. If
disabled for the system, the class A command:
set sassist on
will enable the virtual machjne assist.
machine by issuing the class G command:
set assist on tmr
can then
assist for
enable virtual
your virtual
The restrictions on the use of
the virtual machine assist feature with one addition.
