not a problem when ETW trace is not enabled.

But when I turn it on to investigate potential lock contentions, I notice contentions in the AsyncReaderWriterLock, but further investigating shows it is more artificial when I turn on ETW events.

It seems that ReaderWriterLockIssued event will run into some logic in EventSource to write args mismatches messages, and it runs into other lock contentions to get the resource string.

not sure why this logic is triggered, but some ETW function converts enum to int, but one doesn't. Can this possibly related?

• Microsoft.VisualStudio.Threading!ThreadingEventSource.ReaderWriterLockIssued | 1.7 | 26.736 | 4 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo2_________
  |+ mscorlib.ni!EventSource.WriteEventVarargs | 1.7 | 26.736 | 4 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo2_________
  | + mscorlib.ni!EventSource.LogEventArgsMismatches | 1.7 | 26.736 | 4 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo2_________
  |  + clr!GetResourceFromDefault | 1.7 | 26.736 | 4 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo2_________
  |   + clr!GetResourceStringFromManaged | 1.7 | 26.736 | 4 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo2_________
  |    + clr!MethodDescCallSite::CallTargetWorker | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________
  |    |+ clr!CallDescrWorkerWithHandler | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________
  |    | + clr!CallDescrWorkerInternal | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________
  |    |  + mscorlib.ni!Environment.GetResourceStringLocal | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________
  |    |   + mscorlib.ni!System.Environment+ResourceHelper.GetResourceString(System.String) | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________
  |    |    + mscorlib.ni!System.Environment+ResourceHelper.GetResourceString(System.String, System.Globalization.CultureInfo) | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________
  |    |     + clr!ReflectionInvocation::ExecuteCodeWithGuaranteedCleanup | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________
  |    |      + clr!ExecuteCodeWithGuaranteedCleanupHelper | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________
  |    |       + clr!DispatchCallSimple | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________
  |    |        + clr!CallDescrWorkerWithHandler | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________
  |    |         + clr!CallDescrWorkerInternal | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________
  |    |          + mscorlib.ni!System.Environment+ResourceHelper.GetResourceStringCode(System.Object) | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________
  |    |           + mscorlib.ni!RuntimeResourceSet.GetString | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________
  |    |            + mscorlib.ni!RuntimeResourceSet.GetObject | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________
  |    |             + mscorlib.ni!System.Collections.Generic.Dictionary2[System.__Canon,System.Resources.ResourceLocator].TryGetValue(System.__Canon, System.Resources.ResourceLocator ByRef) | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________ \|    \|              + mscorlib.ni!System.Collections.Generic.Dictionary2[System.Canon,System.Resources.ResourceLocator].FindEntry(System.Canon) | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo______
  |    |               + ntoskrnl!? | 1.7 | 26.393 | 2 | 0.0 | 0 | 0 | 0 | 0 | AAAAAAAAAAAAAAAAAAAAAo__________
  |    |                + BLOCKED_TIME | 1.7 | 26.205 | 1 | 1.7 | 26.205 | 1 | 0 | 0 | AAAAAAAAAAAAAAAAAAAA8___________
  |    |                + CPU_TIME | 0.0 | 0.188 | 1 | 0.0 | 0.188 | 1 | 0 | 0 | __________1o