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Q176211: Console-mode Apps May Run Slowly on Multiprocessor Computers

Article: Q176211
Product(s): Microsoft Windows NT
Version(s): WinNT:4.0
Operating System(s): 
Keyword(s): kb3rdparty kbWinNT400sp4fix
Last Modified: 10-AUG-2001

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The information in this article applies to:

- Microsoft Windows NT Workstation version 4.0 
- Microsoft Windows NT Server version 4.0 
- Microsoft Windows NT Server version 4.0, Terminal Server Edition 
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SYMPTOMS
========

A series of MS-DOS-based console applications may take a long time (perhaps
several minutes) to complete on a multiprocessor computer. The console windows
may remain blank and appear to stop responding (hang). All the applications do
eventually finish, but this may take an unusual amount of time.

The same series of applications will finish in a few seconds on a single
processor computer.

CAUSE
=====

A console handle table lock is being held too long during the freeing of a
console. Processing for other console-related activities is delayed while the
lock is held.

The problem is not usually seen on single processor computers as a context switch
to another console process is unlikely during console cleanup. On a
multiprocessor computer, however, multiple console-mode processes may be
executing simultaneously, which greatly increases the chance of encountering
this problem.

RESOLUTION
==========

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or
Windows NT Server 4.0, Terminal Server Edition. For additional information,
please see the following article in the Microsoft Knowledge Base:

  Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack


This fix modifies console handling so that the handle table lock is released
during noncritical sections of console cleanup. This allows other simultaneously
executing console processes to continue and finish in a reasonable time frame.

STATUS
======

Microsoft has confirmed this to be a problem in Windows NT 4.0 and Windows NT
Server 4.0, Terminal Server Edition. This problem was first corrected in Windows
NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition
Service Pack 4.


MORE INFORMATION
================

All MS-DOS console-mode applications are affected by this problem on
multiprocessor computers under Windows NT 4.0. Windows applications are not
affected.

This problem has been seen when attempting to start multiple PERL scripts as CGI
applications run in console-mode on multiprocessor intranet web servers.


Additional query words: wedge msdos dos box cmd command multi-processor Ntvdm vdm mp
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Keywords          : kb3rdparty kbWinNT400sp4fix 
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbNTTermServ400 kbNTTermServSearch
Version           : WinNT:4.0
Hardware          : ALPHA x86
Issue type        : kbbug
Solution Type     : kbfix

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