Return total memory when limit is max value.

.editorconfig

@@ -202,6 +202,8 @@ resharper_csharp_accessor_owner_body=expression_body
 resharper_redundant_case_label_highlighting=do_not_show
 resharper_redundant_argument_default_value_highlighting=do_not_show
 
+dotnet_diagnostic.IDE0057.severity = none
+
 [*.{sh,bat,ps1}]
 trim_trailing_whitespace=true
 insert_final_newline=true

benchmarks/Elastic.Apm.Benchmarks/CgroupMetricsProviderBenchmarks.cs

@@ -0,0 +1,130 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+using System.Collections.Generic;
+using System.IO;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Engines;
+using Elastic.Apm.Helpers;
+using Elastic.Apm.Metrics.MetricsProvider;
+using Elastic.Apm.Tests.Utilities;
+using static Elastic.Apm.Metrics.MetricsProvider.CgroupMetricsProvider;
+using static Elastic.Apm.Tests.TestHelpers.CgroupFileHelper;
+
+namespace Elastic.Apm.Benchmarks;
+
+[MemoryDiagnoser]
+public class CgroupMetricsProviderBenchmarks
+{
+	private CgroupPaths _cgroupPaths;
+	private CgroupMetricsProvider _cgroupMetricsProvider;
+	private readonly Consumer _consumer = new();
+
+	[GlobalSetup]
+	public void Setup()
+	{
+		_cgroupPaths = CreateDefaultCgroupFiles(CgroupVersion.CgroupV2);
+		_cgroupMetricsProvider = TestableCgroupMetricsProvider(new NoopLogger(), new List<WildcardMatcher>(), _cgroupPaths.RootPath, true);
+	}
+
+	[GlobalSetup(Target = nameof(GetSamplesUnlimited))]
+	public void SetupUnlimited()
+	{
+		_cgroupPaths = CreateDefaultCgroupFiles(CgroupVersion.CgroupV2);
+		UnlimitedMaxMemoryFiles(_cgroupPaths);
+		_cgroupMetricsProvider = TestableCgroupMetricsProvider(new NoopLogger(), new List<WildcardMatcher>(), _cgroupPaths.RootPath, true);
+	}
+
+	private static void UnlimitedMaxMemoryFiles(CgroupPaths paths)
+	{
+		if (paths.CgroupVersion == CgroupVersion.CgroupV1)
+		{
+			using var sr = new StreamWriter(File.Create(Path.Combine(paths.CgroupV1MemoryControllerPath, "memory.limit_in_bytes")));
+			sr.WriteAsync($"9223372036854771712\n");
+		}
+
+		if (paths.CgroupVersion == CgroupVersion.CgroupV2)
+		{
+			using var sr = new StreamWriter(File.Create(Path.Combine(paths.CgroupV2SlicePath, "memory.max")));
+			sr.WriteAsync($"max\n");
+		}
+	}
+
+	[GlobalCleanup]
+	public void Cleanup()
+		=> Directory.Delete(_cgroupPaths.RootPath, true);
+
+	[Benchmark]
+	public void GetSamples()
+	{
+		foreach (var metricSet in _cgroupMetricsProvider.GetSamples())
+		{
+			metricSet.Samples.Consume(_consumer);
+		}
+	}
+
+	// WINDOWS:
+	//|              Method |     Mean |   Error |   StdDev |    Ratio | RatioSD |   Gen0 | Allocated | Alloc Ratio |
+	//|-------------------- |---------:|--------:|---------:|---------:|--------:|-------:|----------:|------------:|
+	//|  GetSamplesOriginal | 433.0 us | 8.39 us | 11.20 us | baseline |         | 1.9531 |   29.4 KB |             |
+	//| GetSamplesOptimised | 409.9 us | 5.11 us |  4.53 us |      -5% |    3.0% |      - |   1.47 KB |        -95% |
+
+	// WINDOWS: After yield return
+	//|              Method |     Mean |   Error |   StdDev |    Ratio | RatioSD |   Gen0 | Allocated | Alloc Ratio |
+	//|-------------------- |---------:|--------:|---------:|---------:|--------:|-------:|----------:|------------:|
+	//|  GetSamplesOriginal | 429.1 us | 8.08 us | 13.93 us | baseline |         | 1.9531 |  29.44 KB |             |
+	//| GetSamplesOptimised | 419.7 us | 6.83 us |  6.39 us |      -5% |    3.3% |      - |   1.46 KB |        -95% |
+
+	// WINDOWS: Remove metric
+	//|              Method |     Mean |   Error |  StdDev | Allocated | Alloc Ratio |
+	//|-------------------- |---------:|--------:|--------:|----------:|------------:|
+	//|          GetSamples | 296.9 us | 3.46 us | 3.23 us |   1.05 KB |        -96% |
+
+	// LINUX: After yield return
+	//|              Method |     Mean |     Error |    StdDev |    Ratio | RatioSD |   Gen0 |   Gen1 | Allocated | Alloc Ratio |
+	//|-------------------- |---------:|----------:|----------:|---------:|--------:|-------:|-------:|----------:|------------:|
+	//|  GetSamplesOriginal | 9.643 us | 0.1600 us | 0.1418 us | baseline |         | 2.3346 | 0.0610 |   29328 B |             |
+	//| GetSamplesOptimised | 5.525 us | 0.0580 us | 0.0569 us |     -43% |    1.6% | 0.0534 |      - |     680 B |        -98% |
+
+	// LINUX: Remove metric
+	//|              Method |     Mean |     Error |    Ratio |    StdDev |   Gen0 | Allocated | Alloc Ratio |
+	//|-------------------- |---------:|----------:|---------:|----------:|-------:|----------:|             |
+	//|          GetSamples | 4.363 us | 0.0458 us |     -55% | 0.0382 us | 0.0381 |     496 B |        -98% |
+
+	[Benchmark]
+	public void GetSamplesUnlimited()
+	{
+		foreach (var metricSet in _cgroupMetricsProvider.GetSamples())
+		{
+			metricSet.Samples.Consume(_consumer);
+		}
+	}
+
+	// WINDOWS:
+	//|              Method |     Mean |   Error |  StdDev |   Gen0 | Allocated |
+	//|-------------------- |---------:|--------:|--------:|-------:|----------:|
+	//| GetSamplesUnlimited | 467.1 us | 9.28 us | 9.11 us | 0.4883 |    9.5 KB |
+
+	// WINDOWS: Optimised
+	//|              Method |     Mean |   Error |  StdDev | Allocated |
+	//|-------------------- |---------:|--------:|--------:|----------:|
+	//| GetSamplesUnlimited | 444.9 us | 8.46 us | 8.69 us |   1.88 KB |
+
+	// WINDOWS: Remove metric
+	//|              Method |     Mean |   Error |  StdDev | Allocated | Alloc Ratio |
+	//|-------------------- |---------:|--------:|--------:|----------:|             |
+	//| GetSamplesUnlimited | 305.4 us | 5.04 us | 4.71 us |   1.43 KB |        -85% |
+
+	// LINUX: Optimised
+	//|              Method |     Mean |     Error |    StdDev |   Gen0 | Allocated |
+	//|-------------------- |---------:|----------:|----------:|-------:|----------:|
+	//| GetSamplesUnlimited | 7.217 us | 0.1375 us | 0.1350 us | 0.0687 |     864 B |
+	//** NOTE: This includes some overhead (176 bytes) for building the test path which is not incurred
+	//in production. This is there equivient to the limited benchmark when this is taken into account.
+
+	// LINUX: Remove metric
+	//|              Method |     Mean |     Error |    StdDev |   Gen0 | Allocated |
+	//|-------------------- |---------:|----------:|----------:|-------:|----------:|
+	//| GetSamplesUnlimited | 4.908 us | 0.0736 us | 0.0688 us | 0.0534 |     680 B |
+}

benchmarks/Elastic.Apm.Benchmarks/Elastic.Apm.Benchmarks.csproj

@@ -10,19 +10,13 @@
   <ItemGroup>
     <PackageReference Include="BenchmarkDotNet" Version="0.13.5" />
     <PackageReference Include="Microsoft.Data.SqlClient" Version="1.1.4" />
-    <PackageReference Include="Elastic.CommonSchema.BenchmarkDotNetExporter" Version="1.5.0"/>
+    <PackageReference Include="Elastic.CommonSchema.BenchmarkDotNetExporter" Version="1.5.0" />
   </ItemGroup>
 
   <ItemGroup>
-    <ProjectReference Include="$(SolutionRoot)\test\integrations\applications\SampleAspNetCoreApp\SampleAspNetCoreApp.csproj"/>
-    <ProjectReference Include="..\..\src\Elastic.Apm\Elastic.Apm.csproj"/>
-    <ProjectReference Include="..\..\test\Elastic.Apm.Tests.Utilities\Elastic.Apm.Tests.Utilities.csproj"/>
-  </ItemGroup>
-
-  <ItemGroup>
-    <Content Include="TestResources\**\*.*">
-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
-    </Content>
+    <ProjectReference Include="$(SolutionRoot)\test\integrations\applications\SampleAspNetCoreApp\SampleAspNetCoreApp.csproj" />
+    <ProjectReference Include="..\..\src\Elastic.Apm\Elastic.Apm.csproj" />
+    <ProjectReference Include="..\..\test\Elastic.Apm.Tests\Elastic.Apm.Tests.csproj" />
   </ItemGroup>
 
 </Project>

benchmarks/Elastic.Apm.Benchmarks/FreeAndTotalMemoryProviderBenchmarks.cs

@@ -0,0 +1,55 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+using System.Collections.Generic;
+using System.IO;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Engines;
+using Elastic.Apm.Helpers;
+using Elastic.Apm.Metrics.MetricsProvider;
+using Elastic.Apm.Tests.Utilities;
+using static Elastic.Apm.Tests.TestHelpers.CgroupFileHelper;
+
+namespace Elastic.Apm.Benchmarks;
+
+[MemoryDiagnoser]
+public class FreeAndTotalMemoryProviderBenchmarks
+{
+	private CgroupPaths _cgroupPaths;
+	private FreeAndTotalMemoryProvider _freeAndTotalMemoryProvider;
+	private readonly Consumer _consumer = new();
+
+	[GlobalSetup]
+	public void Setup()
+	{
+		_cgroupPaths = CreateDefaultCgroupFiles(CgroupVersion.CgroupV2);
+		_freeAndTotalMemoryProvider = FreeAndTotalMemoryProvider
+			.TestableFreeAndTotalMemoryProvider(new NoopLogger(), new List<WildcardMatcher>(), _cgroupPaths.RootPath, true);
+	}
+
+	[GlobalCleanup]
+	public void Cleanup()
+	=> Directory.Delete(_cgroupPaths.RootPath, true);
+
+	[Benchmark]
+	public void GetSamples()
+	{
+		foreach (var metricSet in _freeAndTotalMemoryProvider.GetSamples())
+		{
+			metricSet.Samples.Consume(_consumer);
+		}
+	}
+
+	// WINDOWS
+	//|             Method |     Mean |    Error |   StdDev |    Ratio | RatioSD |   Gen0 | Allocated | Alloc Ratio |
+	//|------------------- |---------:|---------:|---------:|---------:|--------:|-------:|----------:|------------:|
+	//| GetSamplesOriginal | 600.1 ns | 12.00 ns | 17.22 ns | baseline |         | 0.0277 |     352 B |             |
+	//|         GetSamples | 553.8 ns | 10.57 ns | 12.98 ns |      -8% |    3.2% | 0.0162 |     208 B |        -41% |
+
+	// LINUX
+	//|             Method |       Mean |    Error |    StdDev |    Ratio | RatioSD |   Gen0 |   Gen1 | Allocated | Alloc Ratio |
+	//|------------------- |-----------:|---------:|----------:|---------:|--------:|-------:|-------:|----------:|------------:|
+	//| GetSamplesOriginal | 3,693.2 ns | 73.86 ns | 108.27 ns | baseline |         | 0.7324 | 0.0191 |    9216 B |             |
+	//|         GetSamples |   438.7 ns |  8.57 ns |   8.41 ns |     -88% |    3.1% | 0.0215 |      - |     272 B |        -97% |
+}

benchmarks/Elastic.Apm.Benchmarks/MetricsBenchmarks.cs

@@ -58,7 +58,7 @@ public void CollectTotalCpuTime2X()
 		[Benchmark]
 		public void CollectTotalAndFreeMemory2X()
 		{
-			var mockPayloadSender = new FreeAndTotalMemoryProvider(new List<WildcardMatcher>());
+			var mockPayloadSender = new FreeAndTotalMemoryProvider(new NoopLogger(), new List<WildcardMatcher>());
 
 			mockPayloadSender.GetSamples();
 			mockPayloadSender.GetSamples();

benchmarks/Elastic.Apm.Benchmarks/Program.cs

@@ -3,7 +3,10 @@
 // See the LICENSE file in the project root for more information
 
 using System;
+using System.IO;
+using BenchmarkDotNet.Columns;
 using BenchmarkDotNet.Configs;
+using BenchmarkDotNet.Reports;
 using BenchmarkDotNet.Running;
 using Elastic.Apm.Benchmarks.Helpers;
 using Elastic.CommonSchema.BenchmarkDotNetExporter;
@@ -14,6 +17,11 @@ public class Program
 	{
 		public static void Main(string[] args)
 		{
+			//var thing = new FreeAndTotalMemoryProviderBenchmarks();
+			//thing.Setup();
+			//thing.GetSamplesOriginal();
+			//thing.Cleanup();
+
 			var esUrl = Environment.GetEnvironmentVariable("ES_URL");
 			var esPassword = Environment.GetEnvironmentVariable("ES_PASS");
 			var esUser = Environment.GetEnvironmentVariable("ES_USER");
@@ -46,8 +54,11 @@ public static void Main(string[] args)
 				}
 			}
 
-			var exporter = new ElasticsearchBenchmarkExporter(options);
-			var config = DefaultConfig.Instance.AddExporter(exporter);
+			//var exporter = new ElasticsearchBenchmarkExporter(options);
+			var config = DefaultConfig.Instance
+				//.AddExporter(exporter)
+				.WithSummaryStyle(new SummaryStyle(null, false, null, null, ratioStyle: RatioStyle.Percentage));
+
 			BenchmarkSwitcher.FromAssembly(typeof(Program).Assembly).Run(args, config);
 		}
 	}

benchmarks/Elastic.Apm.Profiling/Elastic.Apm.Profiling.csproj

@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsTestProject>false</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="JetBrains.Profiler.Api" Version="1.4.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Elastic.Apm\Elastic.Apm.csproj" />
+    <ProjectReference Include="..\..\test\Elastic.Apm.Tests\Elastic.Apm.Tests.csproj" />
+    <ProjectReference Include="..\Elastic.Apm.Benchmarks\Elastic.Apm.Benchmarks.csproj" />
+  </ItemGroup>
+
+</Project>

benchmarks/Elastic.Apm.Profiling/Program.cs

@@ -0,0 +1,63 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+using Elastic.Apm.Helpers;
+using Elastic.Apm.Logging;
+using Elastic.Apm.Metrics.MetricsProvider;
+using JetBrains.Profiler.Api;
+using static Elastic.Apm.Metrics.MetricsProvider.CgroupMetricsProvider;
+using static Elastic.Apm.Tests.TestHelpers.CgroupFileHelper;
+
+var paths = CreateDefaultCgroupFiles(CgroupVersion.CgroupV1);
+UnlimitedMaxMemoryFiles(paths);
+
+// WARMUP
+
+var sut = TestableCgroupMetricsProvider(new NoopLogger(), new List<WildcardMatcher>(), paths.RootPath, true);
+//var sut = new FreeAndTotalMemoryProvider(new NoopLogger(), new List<WildcardMatcher>());
+foreach (var metricSet in sut.GetSamples())
+	foreach (var _ in metricSet.Samples)
+	{
+	}
+
+// PROFILING
+
+MemoryProfiler.CollectAllocations(true);
+
+MemoryProfiler.GetSnapshot("Before create");
+
+sut = TestableCgroupMetricsProvider(new NoopLogger(), new List<WildcardMatcher>(), paths.RootPath, true);
+//sut = new FreeAndTotalMemoryProvider(new NoopLogger(), new List<WildcardMatcher>());
+
+MemoryProfiler.GetSnapshot("After create");
+
+foreach (var metricSet in sut.GetSamples())
+	foreach (var _ in metricSet.Samples)
+	{
+	}
+
+MemoryProfiler.GetSnapshot("After get samples");
+
+MemoryProfiler.CollectAllocations(false);
+
+static void UnlimitedMaxMemoryFiles(CgroupPaths paths)
+{
+	if (paths.CgroupVersion == CgroupVersion.CgroupV1)
+	{
+		using var sr = new StreamWriter(File.Create(Path.Combine(paths.CgroupV1MemoryControllerPath, "memory.limit_in_bytes")));
+		sr.WriteAsync($"9223372036854771712\n");
+	}
+
+	if (paths.CgroupVersion == CgroupVersion.CgroupV2)
+	{
+		using var sr = new StreamWriter(File.Create(Path.Combine(paths.CgroupV2SlicePath, "memory.max")));
+		sr.WriteAsync($"max\n");
+	}
+}
+
+internal sealed class NoopLogger : IApmLogger
+{
+	public bool IsEnabled(LogLevel level) => false;
+	public void Log<TState>(LogLevel level, TState state, Exception e, Func<TState, Exception, string> formatter) { }
+}

build/scripts/Build.fs

@@ -202,7 +202,7 @@ module Build =
         //dotnet dotnet-format --exclude src/Elastic.Apm/Libraries/
         DotNet.Exec ["dotnet-format"; "--check"; "--exclude"; "src/Elastic.Apm/Libraries/"]
 
-    let private copyDllsAndPdbs (destination: DirectoryInfo) (source: DirectoryInfo) =        
+    let private copyDllsAndPdbs (destination: DirectoryInfo) (source: DirectoryInfo) =
         source.GetFiles()
         |> Seq.filter (fun file -> file.Extension = ".dll" || file.Extension = ".pdb")
         |> Seq.iter (fun file -> file.CopyTo(Path.combine destination.FullName file.Name, true) |> ignore)
@@ -214,7 +214,7 @@ module Build =
         let versionedName =
             sprintf "%s_%s" name (currentAssemblyVersion.ToString())
 
-        let agentDir = Paths.BuildOutput name |> DirectoryInfo                    
+        let agentDir = Paths.BuildOutput name |> DirectoryInfo
         agentDir.Create()
 
         // copy startup hook to root of agent directory

src/Elastic.Apm/Elastic.Apm.csproj

@@ -26,6 +26,7 @@
     <InternalsVisibleTo Include="Elastic.Apm.NetCoreAll.Tests" Key="$(ExposedPublicKey)" />
     <InternalsVisibleTo Include="Elastic.Apm.AspNetCore.Static.Tests" Key="$(ExposedPublicKey)" />
     <InternalsVisibleTo Include="Elastic.Apm.Benchmarks" Key="$(ExposedPublicKey)" />
+    <InternalsVisibleTo Include="Elastic.Apm.Profiling" Key="$(ExposedPublicKey)" />
     <InternalsVisibleTo Include="Elastic.Apm.Docker.Tests" Key="$(ExposedPublicKey)" />
     <InternalsVisibleTo Include="Elastic.Apm.AspNetFullFramework" Key="$(ExposedPublicKey)" />
     <InternalsVisibleTo Include="Elastic.Apm.AspNetFullFramework.Tests" Key="$(ExposedPublicKey)" />