title: WPF : troubleshooting application with occassional high CPU utilization on Win 7 64 using WinDbg
body: <p>I have a .NET 3.5 WPF applicaiton that will occassionalyly utilize 96-99% of CPU time when running only on Win 7 64 bit.  Of course when this happens, even the application itself stops working correctly.  This is another issue that happens only on the 64 bit version of Windows 7.  </p>
  
  <p>The application is currently in this state and I will like to use WinDbg or some other debugging tool to capture as much information as possible.  Anyone online who can help with this in real time?</p>
  
  <p>First off, this is what I can get from Process Explorer:  As the attached image shows <img src="https://i.stack.imgur.com/7zaGn.png" alt="enter image description here">, I have a thread count of 40 with a bunch of them having start address: </p>
  
  <pre><code>mscorwrks.dll!GetMetaDataInternalInterfaceFromPublic+0x934c.  
  </code></pre>
  
  <p>There are about 24 threads currently showing this as the start address.   But I cannot relate this to anything in my code.  </p>
  
  <p>So I am currently attached to the process using WinDbg, which has suspended all threads. Then I did </p>
  
  <pre><code>!runaway 3
  </code></pre>
  
  <p>which gives me:</p>
  
  <pre><code>0:039&gt; !runaway 3
   User Mode Time
    Thread       Time
    33:29bc      0 days 0:27:48.711
    21:2880      0 days 0:26:22.021
    34:18cc      0 days 0:24:38.873
    18:2a04      0 days 0:23:56.753
    23:2618      0 days 0:18:58.947
    24:27e8      0 days 0:17:36.859
    30:21d4      0 days 0:17:05.800
    32:248c      0 days 0:17:04.286
    35:2b00      0 days 0:16:20.809
    22:2680      0 days 0:15:37.597
     5:2a28      0 days 0:15:10.234
    31:ee4       0 days 0:15:07.348
    20:20f0      0 days 0:14:32.903
    17:29ac      0 days 0:14:02.202
    10:20dc      0 days 0:00:51.152
    11:2ad0      0 days 0:00:11.247
    37:2c14      0 days 0:00:06.489
    38:2f3c      0 days 0:00:01.466
    25:1db8      0 days 0:00:00.920
     1:2a84      0 days 0:00:00.452
     0:1494      0 days 0:00:00.093
     2:1ba0      0 days 0:00:00.078
    29:53c       0 days 0:00:00.015
    27:278c      0 days 0:00:00.015
     7:8d4       0 days 0:00:00.015
     4:2620      0 days 0:00:00.015
    39:215c      0 days 0:00:00.000
    36:2088      0 days 0:00:00.000
    28:26e0      0 days 0:00:00.000
    26:2960      0 days 0:00:00.000
    19:2a10      0 days 0:00:00.000
    16:2a70      0 days 0:00:00.000
    15:24a8      0 days 0:00:00.000
    14:2208      0 days 0:00:00.000
    13:2bcc      0 days 0:00:00.000
    12:2a6c      0 days 0:00:00.000
     9:1a38      0 days 0:00:00.000
     8:2a98      0 days 0:00:00.000
     6:1200      0 days 0:00:00.000
     3:2af8      0 days 0:00:00.000
   Kernel Mode Time
    Thread       Time
    11:2ad0      0 days 0:00:03.650
    10:20dc      0 days 0:00:02.230
    33:29bc      0 days 0:00:00.686
    34:18cc      0 days 0:00:00.577
    21:2880      0 days 0:00:00.327
    18:2a04      0 days 0:00:00.327
    24:27e8      0 days 0:00:00.280
    35:2b00      0 days 0:00:00.249
     1:2a84      0 days 0:00:00.218
    30:21d4      0 days 0:00:00.156
    22:2680      0 days 0:00:00.140
     5:2a28      0 days 0:00:00.140
    37:2c14      0 days 0:00:00.124
    23:2618      0 days 0:00:00.109
     2:1ba0      0 days 0:00:00.109
    25:1db8      0 days 0:00:00.093
    20:20f0      0 days 0:00:00.093
    17:29ac      0 days 0:00:00.093
     0:1494      0 days 0:00:00.078
     7:8d4       0 days 0:00:00.062
    32:248c      0 days 0:00:00.046
     3:2af8      0 days 0:00:00.046
    31:ee4       0 days 0:00:00.031
     8:2a98      0 days 0:00:00.031
    38:2f3c      0 days 0:00:00.015
    27:278c      0 days 0:00:00.015
    16:2a70      0 days 0:00:00.015
    15:24a8      0 days 0:00:00.015
    39:215c      0 days 0:00:00.000
    36:2088      0 days 0:00:00.000
    29:53c       0 days 0:00:00.000
    28:26e0      0 days 0:00:00.000
    26:2960      0 days 0:00:00.000
    19:2a10      0 days 0:00:00.000
    14:2208      0 days 0:00:00.000
    13:2bcc      0 days 0:00:00.000
    12:2a6c      0 days 0:00:00.000
     9:1a38      0 days 0:00:00.000
     6:1200      0 days 0:00:00.000
     4:2620      0 days 0:00:00.000
  </code></pre>
  
  <p>When I issue <code>g</code> to continue the process, I get </p>
  
  <pre><code>0:039&gt; g
  (2944.1d6c): Break instruction exception - code 80000003 (first chance)
  mscorlib_ni+0x367240:
  000007fe`f8337240 cc              int     3
  </code></pre>
  
  <p>and process remains suspended.  How do I continue?</p>