perfcollect & PerfView: unable to get events working

[adamsitnik]

While working on dotnet/BenchmarkDotNet#2117 I've very carefully followed the docs and have failed to get a trace file that contains events that could be successfully presented by PerfView. I've tried both x64 and arm64 Ubuntu machines.

The app that I've used:

string path = Path.Combine(Path.GetTempPath(), Path.GetRandomFileName());
string content = new string('a', 100_000);

for (int i = 0; i < 10_000; i++)
	File.WriteAllText(path, content);

File.Delete(path);

Console.WriteLine("Done!");

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFrameworks>net5.0;net6.0;net7.0</TargetFrameworks>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
    <LangVersion>Latest</LangVersion>
  </PropertyGroup>
</Project>

The trace files I got:

net5.trace.zip
net6.trace.zip
net7rc1.trace.zip

@brianrob could you please take a look at these trace files and let me know if I am doing something wrong? I was expecting that with the default settings (COMPlus_PerfMapEnabled=1, COMPlus_EnableEventLog=1) some default events are going to be enabled and captured.

[brianrob]

@adamsitnik, sorry for the delay on this. It looks like something probably went wrong enabling the events in the runtime. Is it possible that COMPlus_EnableEventLog=1 wasn't set for the application itself (as opposed to the collection shell)? The logs show that LTTng is properly installed and was being configured properly, but the traces don't contain any events.

[adamsitnik]

Hello @brianrob !

No worries, for some reason I did not get a notification about your response and here I am, with 2 months delay.

sorry for the delay on this

All the env vars are set:

https://github.com/dotnet/BenchmarkDotNet/blob/12bf220e11fddc8e65b066eb1f300b63bfde7e9b/src/BenchmarkDotNet/Extensions/ProcessExtensions.cs#L133-L142

You can give it a try by cloning BDN and running our sample:

git clone https://github.com/dotnet/BenchmarkDotNet.git
cd BenchmarkDotNet/samples/BenchmarkDotNet.Samples
sudo dotnet run -c Release -f net7.0 --filter '*PerfCollectProfiler*' --job dry