title: .net Application hanging. Weird crash-dump
body: <p>A production server has an application running 24x7, and sometimes it starts consuming near 50% of CPU. I couldn't reproduce it locally, but I did a Memory Dump with adplus.
  The server has Windows 2008 Server 64bits, .NET 3.5. The application listens to a MSMQ and has a thread pool to execute operations, when I did the memory dump it was supposed to be running nothing, but it was still consuming CPU.</p>
  
  <p>Below is the Dump. Do you know what can be happening?? It's weird that the slow thread also says GC Disabled! What's that?</p>
  
  <p>It's weird I've an ASP.NET app in the same server and sometimes happens the same thing.</p>
  
  <pre><code>0:000&gt; !threads
  ThreadCount: 23
  UnstartedThread: 0
  BackgroundThread: 6
  PendingThread: 0
  DeadThread: 5
  Hosted Runtime: no
                                                PreEmptive                                                Lock
         ID OSID        ThreadOBJ     State   GC     GC Alloc Context                  Domain           Count APT Exception
     0    1 1ec0 0000000000249c10      a020 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA
     2    2  84c 0000000000253470      b220 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA (Finalizer)
     3    3 10b8 0000000019d0f900    80a220 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA (Threadpool Completion Port)
     5    4 2184 0000000019d4a550   880b220 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA (Threadpool Completion Port)
     6    6 14a0 0000000019d602a0   180b220 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA (Threadpool Worker)
     8    7  490 0000000019d7db70   200b020 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA
     9    8 2164 0000000019dae680   200b020 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA
    10    9  ac0 0000000019db4740   200b020 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA
    11    a 24cc 0000000019db51f0   200b020 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA
    12    b 1fb4 0000000019db5ca0   200b020 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA
    13    c 2408 0000000019db1520   200b020 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA
    14    d 1b44 0000000019db1fd0   200b020 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA
    15    e 1280 0000000019db2a80   200b020 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA
    16    f 206c 0000000019db8780   200b020 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA
    17   10 1ff8 0000000019db9230   200b020 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA
    18   11 2548 0000000019dc2120   200b020 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA
    20   18 2588 0000000019dc49d0   180b220 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 MTA (Threadpool Worker)
    21   1a 20a0 0000000019dc5570      b220 Disabled 0000000001653d88:0000000001655978 00000000002410b0     1 MTA
  XXXX   26    0 0000000019dc89c0      9820 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 Ukn
  XXXX   2c    0 0000000019dc5b40      9820 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 Ukn
  XXXX   2b    0 0000000019dc3290      9820 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 Ukn
  XXXX    5    0 0000000019dc8f90      9820 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 Ukn
  XXXX   27    0 0000000019dc7850      9820 Enabled  0000000000000000:0000000000000000 00000000002410b0     0 Ukn
  
   0:000&gt; !runaway
   User Mode Time
    Thread       Time
    **21:20a0      0 days 0:27:21.718**
     6:14a0      0 days 0:00:01.921
    18:2548      0 days 0:00:01.015
     2:84c       0 days 0:00:00.890
     (18 more....)
  
  0:000&gt; ~21s
  *** WARNING: Unable to verify checksum for System.ni.dll
  mscorwks!JIT_WriteBarrier_Fast+0x3:
  000007fe`f88de5c3 4881fa607f4701  cmp     rdx,1477F60h
  
  0:021&gt; !clrstack
  OS Thread Id: 0x20a0 (21)
  *** WARNING: Unable to verify checksum for mscorlib.ni.dll
  Child-SP         RetAddr          Call Site
  000000001b05f090 000007fef651b1ba System.Net.TimerThread+TimerNode..ctor(Callback, System.Object, Int32, System.Object)
  000000001b05f0d0 000007fef69a0c3f System.Net.TimerThread+TimerQueue.CreateTimer(Callback, System.Object)
  000000001b05f180 000007fef651b73e System.Net.ConnectionPool.CleanupCallbackWrapper(Timer, Int32, System.Object)
  000000001b05f1d0 000007fef651b560 System.Net.TimerThread+TimerNode.Fire()
  000000001b05f2a0 000007fef64e6388 System.Net.TimerThread+TimerQueue.Fire(Int32 ByRef)
  000000001b05f330 000007fef271175b System.Net.TimerThread.ThreadProc()
  000000001b05f400 000007fef27a95fd System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext, System.Threading.ContextCallback, System.Object)
  000000001b05f450 000007fef88e1552 System.Threading.ThreadHelper.ThreadStart()
  0:021&gt; kb
  RetAddr           : Args to Child      : Call Site
  000007fe`f6a1b87e : 00000000 (Edited) : mscorwks!JIT_WriteBarrier_Fast+0x3
  000007fe`f651b1ba : 00000000 (Edited) : System_ni+0x70b87e
  000007fe`f69a0c3f : 00000000 (Edited) : System_ni+0x20b1ba
  000007fe`f651b73e : 000007fe (Edited) : System_ni+0x690c3f
  000007fe`f651b560 : 00000000 (Edited) : System_ni+0x20b73e
  000007fe`f64e6388 : 00000000 (Edited) : System_ni+0x20b560
  000007fe`f271175b : 00000000 (Edited) : System_ni+0x1d6388
  000007fe`f27a95fd : 00000000 (Edited) : mscorlib_ni+0x2f175b
  000007fe`f88e1552 : 00000000 (Edited) : mscorlib_ni+0x3895fd
  000007fe`f877e5e3 : 00000000 (Edited) : mscorwks!CallDescrWorker+0x82
  000007fe`f878c83f : 00000000 (Edited) : mscorwks!CallDescrWorkerWithHandler+0xd3
  000007fe`f887ae8d : 00000000 (Edited) : mscorwks!MethodDesc::CallDescr+0x24f
  000007fe`f8839374 : 00000000 (Edited) : mscorwks!ThreadNative::KickOffThread_Worker+0x191
  000007fe`f8732045 : 00000000 (Edited) : mscorwks!TypeHandle::GetParent+0x5c
  000007fe`f8846139 : 00000000 (Edited) : mscorwks!SVR::gc_heap::make_heap_segment+0x155
  000007fe`f8700e15 : 00000000 (Edited) : mscorwks!ZapStubPrecode::GetType+0x39
  000007fe`f8700ae7 : 00000000 (Edited) : mscorwks!ThreadNative::KickOffThread+0x401
  000007fe`f88614fc : 00000002 (Edited) : mscorwks!ThreadNative::KickOffThread+0xd3
  00000000`76bdbe3d : 00000000 (Edited) : mscorwks!Thread::intermediateThreadProc+0x78
  00000000`76d16a51 : 00000000 (Edited) : kernel32!BaseThreadInitThunk+0xd
  </code></pre>