Symptoms

Assume that you have a Visual C++ 2010 application that is developed in Microsoft Visual Studio 2010. The application uses the Open Multiprocessing (OpenMP) API to improve performance on a computer that has multiple processors. You build the application, and you use the /openmp compiler option. When you run the application, the application process might experience high CPU usage.

Note This issue does not occur in Microsoft Visual Studio 2008 or in Microsoft Visual Studio 2005.

Cause

This issue occurs because the implementation of the OpenMP runtime (Vcomp100.dll) has a spin-wait loop in which the OpenMP threads look for work for a short time before they are yielded.

Resolution

After you install the hotfix, you must create the OMP_WAIT_POLICY environment variable, and then set the value of the variable to PASSIVE.

Notes

  • If you set the value for OMP_WAIT_POLICY to ACTIVE, the OpenMP threads will spin-wait for a short time before blocking when the threads finish executing a workload.

  • If you set the value for OMP_WAIT_POLICY to PASSIVE, the OpenMP threads will immediately be blocked when the threads finish executing a workload.

  • The default value for OMP_WAIT_POLICY is ACTIVE.

Hotfix information

A supported hotfix is now available from Microsoft. However, it is intended to correct only the problem that is described in this article. Apply it only to systems that are experiencing this specific problem. This hotfix may 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.

To resolve this problem immediately, contact Microsoft Customer Support Services to obtain the hotfix. For a complete list of Microsoft Customer Support Services telephone numbers and information about support costs, visit the following Microsoft website:

http://support.microsoft.com/contactus/?ws=supportNote In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

Prerequisites

To apply this hotfix, you must have Visual Studio 2010 Service Pack 1 (SP1) installed.

Restart requirement

You must restart the computer after you install the hotfix if the affected files are being used during the installation.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

File information

The global 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 item in Control Panel.

File name

File version

File size

Date

Time

Platform

atl100.dll

10.0.40219.436

159280

14-Dec-2012

5:46

x64

atl100.dll

10.0.40219.436

386096

14-Dec-2012

6:07

ia64

atl100.dll

10.0.40219.436

138800

14-Dec-2012

6:35

x86

mfc100.dll

10.0.40219.436

5579824

14-Dec-2012

5:46

x64

mfc100.dll

10.0.40219.436

4400688

14-Dec-2012

6:35

x86

mfc100chs.dll

10.0.40219.436

36912

14-Dec-2012

5:46

x64

mfc100chs.dll

10.0.40219.436

36912

14-Dec-2012

6:35

x86

mfc100cht.dll

10.0.40219.436

36936

14-Dec-2012

5:46

x64

mfc100cht.dll

10.0.40219.436

36912

14-Dec-2012

6:35

x86

mfc100d.dll

10.0.40219.436

9144368

14-Dec-2012

8:00

x64

mfc100d.dll

10.0.40219.436

7064128

14-Dec-2012

8:30

x86

mfc100deu.dll

10.0.40219.436

65072

14-Dec-2012

5:46

x64

mfc100deu.dll

10.0.40219.436

65096

14-Dec-2012

6:35

x86

mfc100enu.dll

10.0.40219.436

55880

14-Dec-2012

5:46

x64

mfc100enu.dll

10.0.40219.436

55880

14-Dec-2012

6:35

x86

mfc100esn.dll

10.0.40219.436

64560

14-Dec-2012

5:46

x64

mfc100esn.dll

10.0.40219.436

64560

14-Dec-2012

6:35

x86

mfc100fra.dll

10.0.40219.436

65096

14-Dec-2012

5:46

x64

mfc100fra.dll

10.0.40219.436

65072

14-Dec-2012

6:35

x86

mfc100ita.dll

10.0.40219.436

63024

14-Dec-2012

5:46

x64

mfc100ita.dll

10.0.40219.436

63048

14-Dec-2012

6:35

x86

mfc100jpn.dll

10.0.40219.436

44592

14-Dec-2012

5:46

x64

mfc100jpn.dll

10.0.40219.436

44592

14-Dec-2012

6:35

x86

mfc100kor.dll

10.0.40219.436

44080

14-Dec-2012

5:46

x64

mfc100kor.dll

10.0.40219.436

44104

14-Dec-2012

6:35

x86

mfc100rus.dll

10.0.40219.436

61488

14-Dec-2012

5:46

x64

mfc100rus.dll

10.0.40219.436

61512

14-Dec-2012

6:35

x86

mfc100u.dll

10.0.40219.436

5605952

14-Dec-2012

5:46

x64

mfc100u.dll

10.0.40219.436

4425776

14-Dec-2012

6:35

x86

mfc100ud.dll

10.0.40219.436

9220656

14-Dec-2012

8:00

x64

mfc100ud.dll

10.0.40219.436

7132736

14-Dec-2012

8:30

x86

mfcm100.dll

10.0.40219.436

93744

14-Dec-2012

5:46

x64

mfcm100.dll

10.0.40219.436

82496

14-Dec-2012

6:35

x86

mfcm100d.dll

10.0.40219.436

120368

14-Dec-2012

8:00

x64

mfcm100d.dll

10.0.40219.436

104512

14-Dec-2012

8:30

x86

mfcm100u.dll

10.0.40219.436

93744

14-Dec-2012

5:46

x64

mfcm100u.dll

10.0.40219.436

82496

14-Dec-2012

6:35

x86

mfcm100ud.dll

10.0.40219.436

121904

14-Dec-2012

8:00

x64

mfcm100ud.dll

10.0.40219.436

106056

14-Dec-2012

8:30

x86

mfcmifc80u.dll

10.0.40219.436

13872

15-Dec-2012

16:06

x86

msvcp100.dll

10.0.40219.436

608816

14-Dec-2012

5:46

x64

msvcp100.dll

10.0.40219.436

967232

14-Dec-2012

6:07

ia64

msvcp100.dll

10.0.40219.436

421936

14-Dec-2012

6:35

x86

msvcp100d.dll

10.0.40219.436

1979952

14-Dec-2012

7:34

ia64

msvcp100d.dll

10.0.40219.436

1015344

14-Dec-2012

8:06

x64

msvcp100d.dll

10.0.40219.436

744496

14-Dec-2012

8:36

x86

msvcr100_clr0400.dll

10.0.40219.436

830016

14-Dec-2012

5:46

x64

msvcr100_clr0400.dll

10.0.40219.436

1500224

14-Dec-2012

6:07

ia64

msvcr100_clr0400.dll

10.0.40219.436

774192

14-Dec-2012

6:35

x86

msvcr100d_clr0400.dll

10.0.40219.436

3764784

14-Dec-2012

7:34

ia64

msvcr100d_clr0400.dll

10.0.40219.436

1873968

14-Dec-2012

8:06

x64

msvcr100d_clr0400.dll

10.0.40219.436

1506352

14-Dec-2012

8:36

x86

vcomp100.dll

10.0.40219.436

58944

14-Dec-2012

5:46

x64

vcomp100.dll

10.0.40219.436

144448

14-Dec-2012

6:07

ia64

vcomp100.dll

10.0.40219.436

52288

14-Dec-2012

6:35

x86

vcomp100d.dll

10.0.40219.436

318512

14-Dec-2012

7:29

ia64

vcomp100d.dll

10.0.40219.436

108616

14-Dec-2012

7:54

x64

vcomp100d.dll

10.0.40219.436

89648

14-Dec-2012

8:24

x86

vcomp100ui.dll

10.0.40219.436

10296

15-Dec-2012

16:06

x86

vcomp100ui.dll

10.0.40219.436

10312

15-Dec-2012

16:06

x86

vcomp100ui.dll

10.0.40219.436

10808

15-Dec-2012

16:06

x86

vcomp100ui.dll

10.0.40219.436

10824

15-Dec-2012

16:06

x86

vcomp100ui.dll

10.0.40219.436

11832

15-Dec-2012

16:06

x86

vcomp100ui.dll

10.0.40219.436

12344

15-Dec-2012

16:06

x86

vcomp100ui.dll

10.0.40219.436

12360

15-Dec-2012

16:06

ia64

vcredist_ia64.exe

10.0.40219.436

3043304

14-Dec-2012

10:00

x86

vcredist_x64.exe

10.0.40219.436

10296288

14-Dec-2012

9:57

x86

vcredist_x86.exe

10.0.40219.436

8994272

14-Dec-2012

10:03

x86

More Information

For more information about the OpenMP API in Visual Studio 2010, go to the following MSDN website:

General information about the OpenMP APIFor more information about OpenMP in Visual C++, go to the following MSDN website:

General information about OpenMP in Visual C++

Status

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

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