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VPC.exe uses Max CPU - MSVCRT.DLL Thread at max CPU in the VPC process RRS feed

  • Question

  • Hello,

    I have been troubleshooting VPC.exe for XP Mode for some time. I have been using Process Explorer lately to narrow down the exact source of the problem.

    If I kill the thread within the VPC.exe process which exhibits high CPU usage performance returns to normal. The delinquent thread is consuming MSVCRT.DLL. There is no noticeable loss of functionality on the VPC having killed the thread.

    What happens in Hibernation: After killing the delinquent thread, putting the XP Mode VPC in hibernation and then bringing it back to working mode does not cause the delinquent thread to re-fire. CPU usage appears to be normal.

    What happens in Restart: After killing the delinquent thread, a restart cycle of the XP Mode VPC did not trigger the delinquent thread.

    It appears that under some circumstances VPC calls a thread that will not terminate and must be terminated manually or high CPU usage will result.

    What happens after the VPC.exe Process is restarted: If you restart the VPC process and then power up the XP Mode VPC from a shutdown state the problem reappears. The thread continues to consume max CPU until it is killed.

    Here is the stack for the thread:

    ntoskrnl.exe!memset+0x65a
    ntoskrnl.exe!FsRtlInitializeBaseMcb+0x1ae
    ntoskrnl.exe!CcGetFlushedValidData+0x1701
    ntoskrnl.exe!ObDereferenceObjectDeferDelete+0x1e7
    ntoskrnl.exe!ObDereferenceObjectDeferDelete+0x457
    KERNELBASE.dll!GetTickCount+0x7
    vpc.exe+0x1b283b
    vpc.exe+0x80b21
    vpc.exe+0xab80a
    vpc.exe+0x18939b
    vpc.exe+0x78b03
    vpc.exe+0x81a71
    vpc.exe+0x81687
    vpc.exe+0x835db
    msvcrt.dll!sqrt+0x7f
    msvcrt.dll!beginthreadex+0x131
    kernel32.dll!BaseThreadInitThunk+0xd
    ntdll.dll!RtlUserThreadStart+0x21

    What answers this question: An answer to this question would be to resolve the delinquent thread that consumes maximum CPU when the VPC.exe process is restarted without requiring it to be manually killed using Process Explorer.


    Jeff Loucks | Available Technology | 888-474-2237 | http://msmvps.com/blogs/jeffloucks

    Wednesday, October 13, 2010 8:40 AM

Answers

  • Hey Jeff,

    I checked and it looks like the issue you opened up through the Connect web site is progressing well.  At this point it  the SP1 beta team is taking a look at it to see what's causing it.  They should get back to you via Connect once they have their analysis done.

    For anyone else experiencing this issue (or other issues) and using the SP1 beta, please make sure you notify the product team via the Connect website - that way we can make sure that problems are fixed prior to release of the service pack!


    David Beach - Microsoft Online Community Support
    • Marked as answer by Magon Liu Tuesday, May 3, 2011 8:05 AM
    Thursday, October 21, 2010 2:29 PM

All replies

  • Hi,

    make a xperf trace with the help of my guide on msfn [1] to diagnostic the high CPU usage. Please upload the etl file to your SkyDrive [2] and post a link here.

    I'll take a look at it.

    André

    [1] http://www.msfn.org/board/index.php?showtopic=140264
    [2] http://social.technet.microsoft.com/Forums/en-US/w7itproui/thread/4fc10639-02db-4665-993a-08d865088d65
    "A programmer is just a tool which converts caffeine into code" CLIP- Stellvertreter http://www.winvistaside.de/
    • Proposed as answer by Andre.Ziegler Thursday, October 14, 2010 11:13 AM
    Wednesday, October 13, 2010 10:51 AM
  • Hi,

     

    Thanks for posting in Microsoft TechNet forums.

     

    Msvcrt.dll is the Microsoft Visual C++ Run-Time for Visual C++ versions 4.2 to 6.0. It provides programs compiled with these versions of Visual C++ a typical set of library functions required by C and C++ programs. These include string manipulation, memory allocation, C-style input/output calls, etc.

     

    If you do a "Find" on msvcrt.dll you will get a list of all the programs calling it.  Amone them are, alg.exe, iexplore.exe cmd.exe notepad.exe , just about everything.

     

    I would appreciate if you can clarify the following question:

     

    1. When did this issue begin to occur? If recently, system restore can be under consideration.

    2. Can you associate with any software\hardware change?

     

    At this point, I would suggest have a look whether you can reproduce the problem in safe mode and clean boot to help us determine if this issue is due to hardware or software factors.

     

    Best Regards

    Magon Liu

    TechNet Subscriber Support in forum. If you have any feedback on our support, please contact tngfb@microsoft.com


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. ”
    Thursday, October 14, 2010 8:43 AM
  • Hi,

     

    Thanks for posting in Microsoft TechNet forums.

    As this thread has been quiet for a while, we assume that the issue has been resolved. At this time, we will mark it as ‘Answered’ as the previous steps should be helpful for many similar scenarios. If the issue still persists, please feel free to  reply this post directly so we will be notified to follow it up. You can also choose to unmark the answer as you wish.

    BTW,  we’d love to hear your feedback about the solution. By sharing your experience you can help other community members facing similar problems. Thanks for your understanding and efforts.

     

    Best Regards

    Magon Liu

    TechNet Subscriber Support in forum. If you have any feedback on our support, please contact tngfb@microsoft.com

     


    Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. ”
    Monday, October 18, 2010 2:53 AM
  • This issue is still on going.

    I have not had time to deal with it. I started down the path that Andre suggested and because it took so much time I got pulled away.

    As for Magon's questions. No software that I know of except Windows 7 SP1 Beta which is why I cross posted into the beta site.

    I am sure that people want a solution to this problem. I intend to get back to this when I have time.


    Jeff Loucks | Available Technology | 888-474-2237 | http://msmvps.com/blogs/jeffloucks
    Monday, October 18, 2010 5:45 PM
  • Hey Jeff,

    I checked and it looks like the issue you opened up through the Connect web site is progressing well.  At this point it  the SP1 beta team is taking a look at it to see what's causing it.  They should get back to you via Connect once they have their analysis done.

    For anyone else experiencing this issue (or other issues) and using the SP1 beta, please make sure you notify the product team via the Connect website - that way we can make sure that problems are fixed prior to release of the service pack!


    David Beach - Microsoft Online Community Support
    • Marked as answer by Magon Liu Tuesday, May 3, 2011 8:05 AM
    Thursday, October 21, 2010 2:29 PM
  • I have found the same issue with vpc.exe consuming one core entirely.

    I killed the msvcrt thread that was consuming the CPU and it didn't affect the virtual machine at all. Not until I put the host into standby and then when it came out the XP Mode VM was blank and unresponsive.

    I had been trying to improve its performance before I got an SSD and think I may have tried (probably in vain) a bit of advice given elsewhere:

    1. In the Open dialog box, type %localappdata%\Microsoft\Windows Virtual PC\Options.xml in the File name box, and then click Open.
    2. Under the <virtual_machines> tag, add the following line:
      <enable_idle_thread type="boolean">true</enable_idle_thread>

    I think this is what was causing the problem and so I changed it back to false and restarted the machine and it now consumes a sensible, mostly sub 1%, of CPU.

    Monday, February 17, 2014 12:29 PM