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- DOCUMENT:Q103810 06-JAN-1994 [W_NT]
- TITLE :Realtime Priority Applications And Windows NT
- PRODUCT :Windows NT
- PROD/VER:3.10
- OPER/SYS:WINDOWS
- KEYWORDS:
-
- --------------------------------------------------------------------
- The information in this article applies to:
-
- - Microsoft Windows NT operating system version 3.1
- - Microsoft Windows NT Advanced Server version 3.1
- --------------------------------------------------------------------
-
- SUMMARY
- =======
-
- An application that is running in the RealTime priority class (a base
- priority of 16) can potentially take so much of the available CPU
- resources that no resources will be available for other processes or
- threads. This includes a possible "starving" of both the mouse and
- keyboard. This implies that the mouse may become unavailable to click
- another application to execute an action. It also implies that the
- keyboard may not respond if you try to press CTRL+ESC to get the Task
- List and Cancel the application.
-
- To run a process or thread in the RealTime priority class requires
- that you either be an administrator, a member of the administrator's
- group, or have the Increase Scheduling Priority user right
- (SeIncreaseBasePriorityPrivilege) explicitly granted to you.
- Administrators must use caution when granting this right to users.
-
- MORE INFORMATION
- ================
-
- Only Windows 32-bit applications can be scheduled for RealTime and
- High priorities. Windows 16-bit, MS-DOS, OS/2, and POSIX applications
- may only run at a priority of Normal (maximum base priority of 7).
- Also, if a process has a Low priority, all processes spawned from it
- (children) will inherit the Low priority, but if the process has a
- High priority, all children will be assigned a Normal priority.
-
- Default Priority Bases
- ----------------------
-
- Low: 4
- Normal: 7
- High: 13
- RealTime: 24
-
- Note that many items can influence this base priority, including user
- groups (administrators versus users), how tasking is set up in the
- Control Panel System option, and whether the application is in the
- foreground or background.
-
- Additional reference words: 3.10 lockup CPU-bound real time
- KBCategory:
- KBSubCategory: pertune
-
- =============================================================================
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- Copyright Microsoft Corporation 1994.