Minor event pipe profiler improvements (#1381)

Author: adamsitnik

samples/BenchmarkDotNet.Samples/IntroEventPipeProfilerAdvance.cs renamed to samples/BenchmarkDotNet.Samples/IntroEventPipeProfilerAdvanced.cs

@@ -1,5 +1,4 @@
-using System;
-using System.Buffers;
+using System.Buffers;
 using System.Diagnostics.Tracing;
 using BenchmarkDotNet.Attributes;
 using BenchmarkDotNet.Configs;
@@ -12,7 +11,7 @@
 namespace BenchmarkDotNet.Samples
 {
     [Config(typeof(CustomConfig))]
-    public class IntroEventPipeProfilerAdvance
+    public class IntroEventPipeProfilerAdvanced
     {
         private class CustomConfig : ManualConfig
         {
@@ -22,13 +21,14 @@ public CustomConfig()
 
                 var providers = new[]
                 {
-                    new EventPipeProvider(ClrTraceEventParser.ProviderName, EventLevel.Verbose, (long) (ClrTraceEventParser.Keywords.Exception
-                                                                                                        | ClrTraceEventParser.Keywords.GC
-                                                                                                        | ClrTraceEventParser.Keywords.Jit
-                                                                                                        | ClrTraceEventParser.Keywords.JitTracing // for the inlining events
-                                                                                                        | ClrTraceEventParser.Keywords.Loader
-                                                                                                        | ClrTraceEventParser.Keywords.NGen)),
-                    new EventPipeProvider("System.Buffers.ArrayPoolEventSource", EventLevel.Informational, Int64.MaxValue),
+                    new EventPipeProvider(ClrTraceEventParser.ProviderName, EventLevel.Verbose,
+                        (long) (ClrTraceEventParser.Keywords.Exception
+                        | ClrTraceEventParser.Keywords.GC
+                        | ClrTraceEventParser.Keywords.Jit
+                        | ClrTraceEventParser.Keywords.JitTracing // for the inlining events
+                        | ClrTraceEventParser.Keywords.Loader
+                        | ClrTraceEventParser.Keywords.NGen)),
+                    new EventPipeProvider("System.Buffers.ArrayPoolEventSource", EventLevel.Informational, long.MaxValue),
                 };
 
                 AddDiagnoser(new EventPipeProfiler(providers: providers));

src/BenchmarkDotNet.Diagnostics.Windows/Sessions.cs

@@ -103,8 +103,7 @@ protected Session(string sessionName, DiagnoserActionParameters details, EtwProf
         {
             Details = details;
             Config = config;
-            FilePath = ArtifactFileNameHelper.GetFilePath(details, creationTime, FileExtension);
-            Path.GetDirectoryName(FilePath).CreateIfNotExists();
+            FilePath = ArtifactFileNameHelper.GetFilePath(details, creationTime, FileExtension).EnsureFolderExists();
             TraceEventSession = new TraceEventSession(sessionName, FilePath)
             {
                 BufferSizeMB = config.BufferSizeInMb,

src/BenchmarkDotNet/Diagnosers/EventPipeProfile.cs

@@ -2,8 +2,24 @@
 {
     public enum EventPipeProfile
     {
+        /// <summary>
+        /// Useful for tracking CPU usage and general .NET runtime information.
+        /// This is the default option if no profile or providers are specified.
+        /// </summary>
         CpuSampling,
+        /// <summary>
+        /// Tracks GC collections and samples object allocations.
+        /// </summary>
         GcVerbose,
-        GcCollect
+        /// <summary>
+        /// Tracks GC collections only at very low overhead.
+        /// </summary>
+        GcCollect,
+        /// <summary>
+        /// Logging when Just in time (JIT) compilation occurs.
+        /// Logging of the internal workings of the Just In Time compiler. This is fairly verbose.
+        /// It details decisions about interesting optimization (like inlining and tail call)
+        /// </summary>
+        Jit
     }
 }

src/BenchmarkDotNet/Diagnosers/EventPipeProfileMapper.cs

@@ -3,42 +3,52 @@
 using Microsoft.Diagnostics.NETCore.Client;
 using Microsoft.Diagnostics.Tracing.Parsers;
 
-namespace BenchmarkDotNet.Diagnosers 
+namespace BenchmarkDotNet.Diagnosers
 {
     internal sealed class EventPipeProfileMapper
     {
-        internal static IReadOnlyDictionary<EventPipeProfile, EventPipeProvider[]> DotNetRuntimeProfiles { get; } = new Dictionary<EventPipeProfile, EventPipeProvider[]>
+        private const string DotNetRuntimeProviderName = "Microsoft-Windows-DotNETRuntime";
+
+        internal static IReadOnlyDictionary<EventPipeProfile, IReadOnlyList<EventPipeProvider>> DotNetRuntimeProfiles { get; } = new Dictionary<EventPipeProfile, IReadOnlyList<EventPipeProvider>>
         {
-            //Useful for tracking CPU usage and general .NET runtime information. This is the default option if no profile or providers are specified.
             { EventPipeProfile.CpuSampling,
                 new[]
                 {
                     new EventPipeProvider("Microsoft-DotNETCore-SampleProfiler", EventLevel.Informational),
-                    new EventPipeProvider("Microsoft-Windows-DotNETRuntime", EventLevel.Informational, (long) ClrTraceEventParser.Keywords.Default)
+                    new EventPipeProvider(DotNetRuntimeProviderName, EventLevel.Informational, (long) ClrTraceEventParser.Keywords.Default)
                 }},
-            //Tracks GC collections and samples object allocations.
-            {EventPipeProfile.GcVerbose,
+            { EventPipeProfile.GcVerbose,
                 new[]
                 {
                     new EventPipeProvider(
-                        name: "Microsoft-Windows-DotNETRuntime",
+                        name: DotNetRuntimeProviderName,
                         eventLevel: EventLevel.Verbose,
                         keywords: (long) ClrTraceEventParser.Keywords.GC |
                                   (long) ClrTraceEventParser.Keywords.GCHandle |
                                   (long) ClrTraceEventParser.Keywords.Exception
                     ),
                 }},
-            //Tracks GC collections only at very low overhead.
-            {EventPipeProfile.GcCollect,
+            { EventPipeProfile.GcCollect,
                 new[]
                 {
                     new EventPipeProvider(
-                        name: "Microsoft-Windows-DotNETRuntime",
+                        name: DotNetRuntimeProviderName,
                         eventLevel: EventLevel.Informational,
                         keywords: (long) ClrTraceEventParser.Keywords.GC |
                                   (long) ClrTraceEventParser.Keywords.Exception
                     )
                 }},
+            { EventPipeProfile.Jit,
+                new[]
+                {
+                    new EventPipeProvider(
+                        name: DotNetRuntimeProviderName,
+                        eventLevel: EventLevel.Verbose,
+                        keywords: (long) ClrTraceEventParser.Keywords.Jit |
+                                  (long) ClrTraceEventParser.Keywords.JitTracing |
+                                  (long) ClrTraceEventParser.Keywords.Exception
+                    )
+                }},
         };
     }
 }