INFO: Win32 Priority Class Mechanism and the START Command

ID: Q90910

The information in this article applies to:

Microsoft Win32 Application Programming Interface (API), used with:
- Microsoft Windows NT versions 3.5, 3.51, 4.0
- Microsoft Windows 2000

SUMMARY

The Win32 priority class mechanism is exposed through CMD.EXE's START command.

START accepts the following switches:


   /LOW        -  Start the command in the idle priority class.

   /NORMAL     -  Start the command in the normal priority class
                  (this is the default).

   /HIGH       -  Start the command in the high priority class.

   /REALTIME   -  Start the command in the real-time priority class.

   /ABOVENORMAL -  Start the command in the above normal priority class.

   /BELOWNORMAL -  Start the command in the below normal priority class.

For a complete list of START switches, type the following command at the Windows NT command prompt:

start /?

Win32 has also been modified to inherit priority class if the parent's priority class is idle; thus, a command such as

start /LOW nmake

causes build and all descendants (compiles, links, and so on) to run in the idle priority class. Use this method to do a real background build that will not interfere with anything else on your system.

A command such as

start /HIGH nmake

runs BUILD.EXE in the high priority class, but all descendants run in the normal priority class.

MORE INFORMATION

Be very careful with START /HIGH and START /REALTIME. If you use either of these switches to start applications that require a lot of cycles, the applications will get all the cycles they ask for, that may cause the system to appear hung.

Additional query words: 3.50

Keywords : kbKernBase kbNTOS350 kbNTOS351 kbNTOS400 kbWinOS2000 kbThread kbDSupport kbGrpKernBase
Version : winnt:3.5,3.51,4.0
Platform : winnt
Issue type : kbinfo