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Performance degradation occurs in the UnmapViewOfFile function
Article ID: 815227 - View products that this article applies to.
A program that uses mapped file views that are larger than 500 megabytes (MB) may experience a significant performance decrease. Mapped file views are frequently used to share information between two or more processes. The performance degradation occurs in the UnmapViewOfFile function.
This problem occurs if a program maps file views that are larger than 500 MB in Microsoft Windows Server 2003 or in Microsoft Windows XP Service Pack 1 (SP1).
Windows XP Service Pack 1
Service pack informationTo resolve this problem, obtain the latest service pack for Windows XP. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/322389/ )How to obtain the latest Windows XP service pack
Hotfix informationA supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.
If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.
Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site:
http://support.microsoft.com/contactus/?ws=supportNote The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language. The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.
Date Time Version Size File name Platform ----------------------------------------------------------------------- 28-Feb-2003 16:17 5.1.2600.1178 1,895,424 Ntkrnlmp.exe i386 28-Feb-2003 16:17 5.1.2600.1178 1,951,232 Ntkrnlpa.exe i386 28-Feb-2003 16:17 5.1.2600.1178 1,923,584 Ntkrpamp.exe i386 28-Feb-2003 16:17 5.1.2600.1178 1,927,424 Ntoskrnl.exe i386 28-Feb-2003 16:17 5.1.2600.1178 5,826,432 Ntkrnlmp.exe ia-64 28-Feb-2003 16:17 5.1.2600.1178 5,736,704 Ntoskrnl.exe ia-64
Windows Server 2003Although the problem manifests with a call to the UnmapViewOfFile function, the required code change is deep within the kernel. Because of the risk of changing core memory management functions, a hotfix for Windows Server 2003 will not be available. The code fix for Windows Server 2003 will be available in Windows Server 2003 Service Pack 1.
Programs that could be affected by this problem can be identified by using Performance Monitor. To do this, follow these steps:
If the program is affected by this performance issue, the following coding workarounds are available for Windows Server 2003 until Windows Server 2003 Service Pack 1 is available:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Microsoft Windows XP Service Pack 2. The problem is scheduled to be fixed in Windows Server 2003 Service Pack 1.
Article ID: 815227 - Last Review: August 29, 2007 - Revision: 6.3