Win32 Priority Class Mechanism and the START Command

Last reviewed: December 16, 1996
Article ID: Q90910

The information in this article applies to:

Microsoft Win32 Application Programming Interface (API) included with:
```
    - Microsoft Windows NT versions 3.5, 3.51, and 4.00
```

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.

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 reference words: 3.50 3.51 4.00
KBCategory: kbprg
KBSubcategory: BseProcThrd

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Last reviewed: December 16, 1996
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