Browse Prior Art Database

Method to Determine Idle Time of a Computer's Central Processing Unit

IP.com Disclosure Number: IPCOM000107539D
Original Publication Date: 1992-Mar-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 2 page(s) / 74K

Publishing Venue

IBM

Related People

Bishop, DA: AUTHOR [+4]

Abstract

Disclosed is a method to accurately determine the idle time of a computer's Central Processing Unit.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Method to Determine Idle Time of a Computer's Central Processing Unit

       Disclosed is a method to accurately determine the idle
time of a computer's Central Processing Unit.

      Idle time in a computer is the amount of time the computer's
Central Processing Unit (CPU) is not being utilized by any task.

      Specific hooks are turned on in the IBM OS/2* STRACE
environment using the TRACE command.  SYSTRACE provides a
time-stamped event trace of system activity, including each time a
process/thread is dispatched and each time a process/thread execution
is preempted by an interrupt, or by a software action that results in
another process/thread being dispatched.  Thus, the time is read when
each process/thread gains control of the CPU and when it loses
control.  Simple subtraction gives the amount of time spent in each
process/thread.

      A process, IDLECPU.EXE, is started and assigned the lowest
level priority in the system.  Using the SYSTRACE process dispatch
and interrupt event information, the amount of time the IDLECPU.EXE
process is executing in the system is tracked.  Since all other
processes must have higher dispatch priority, the IDLECPU.EXE process
executes only when all other processes have completed their tasks or
cannot proceed until some external event (e.g., completion of
requested I/O) occurs which, once again, makes them dispatchable.
The amount of time the system is idle (or available to perform
additional tasks) is the amount of time the IDLECPU process is
executing.  This can be done at any time, even when the CPU is under
severe overload conditions. This method h...