[Instrumentation.Process] Update .NET API for virtual memory usage

src/OpenTelemetry.Instrumentation.Process/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+* Update the .NET API used to retrieve `process.memory.virtual` metric to be
+  `Process.VirtualMemorySize64`.
+  ([#762](https://github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/762))
+
 * Update OTel API version to be `1.4.0-beta.2` and change process metrics type
   from ObservableGauge to `ObservableUpDownCounter`. Updated instruments are:
   "process.memory.usage", "process.memory.virtual" and "process.threads".

src/OpenTelemetry.Instrumentation.Process/ProcessMetrics.cs

@@ -51,10 +51,10 @@ public ProcessMetrics(ProcessInstrumentationOptions options)
             "process.memory.virtual",
             () =>
             {
-                return Diagnostics.Process.GetCurrentProcess().PrivateMemorySize64;
+                return Diagnostics.Process.GetCurrentProcess().VirtualMemorySize64;
             },
             unit: "By",
-            description: "The amount of virtual memory allocated for this process that cannot be shared with other processes.");
+            description: "The amount of committed virtual memory for this process.");
 
         this.MeterInstance.CreateObservableCounter(
             "process.cpu.time",

src/OpenTelemetry.Instrumentation.Process/README.md

@@ -61,17 +61,19 @@ allocated for the associated process.
 
 ### process.memory.virtual
 
-The amount of virtual memory allocated for this process
-that cannot be shared with other processes.
+The amount of committed virtual memory for this process.
+One way to think of this is all the address space this process can read from
+without trigerring an access violation; including memory backed solely by RAM,
+pagefile-backed memory and file-backed memory.
 
 | Units | Instrument Type         | Value Type |
 |-------|-------------------------|------------|
 |  `By` | ObservableUpDownCounter | `Double`   |
 
 The API used to retrieve the value is:
 
-* [Process.WorkingSet64](https://learn.microsoft.com/dotnet/api/system.diagnostics.process.privatememorysize64):
-Gets the amount of private memory, in bytes,
+* [Process.VirtualMemorySize64](https://learn.microsoft.com/dotnet/api/system.diagnostics.process.virtualmemorysize64):
+Gets the amount of the virtual memory, in bytes,
 allocated for the associated process.
 
 ### process.cpu.time