[Perf] Linux/x64: System.Text.Json.Serialization.Tests.ReadJson Regression on 1/30/2025 12:05:17 AM +00:00

[performanceautofiler]

Run Information

Name	Value
Architecture	x64
OS	ubuntu 22.04
Queue	ViperUbuntu
Baseline	bcc0e894256b22736be3ffac876c7f21cffe070a
Compare	7693b6d0202281dc38dcfb9562e9064fcd13bc61
Diff	Diff
Configs	CompilationMode:tiered, RunKind:micro

Regressions in System.Text.Json.Serialization.Tests.ReadJson<Int32>

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector	Baseline IR	Compare IR	IR Ratio
DeserializeFromStream - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	199.67 ns	227.14 ns	1.14	0.17	False

Test Report

Repro

General Docs link: https://github.com/dotnet/performance/blob/main/docs/benchmarking-workflow-dotnet-runtime.md

git clone https://github.com/dotnet/performance.git
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Text.Json.Serialization.Tests.ReadJson<Int32>*'

System.Text.Json.Serialization.Tests.ReadJson<Int32>.DeserializeFromStream(Mode: Reflection)

ETL Files

Histogram

JIT Disasms

Docs

Profiling workflow for dotnet/runtime repository
Benchmarking workflow for dotnet/runtime repository

[LoopedBard3]

Potentially caused by #111023. FYI @tannergooding. From range: d551abb...f3d90b2.

[dotnet-policy-service]

Tagging subscribers to this area: @dotnet/area-system-text-json, @gregsdennis
See info in area-owners.md if you want to be subscribed.

[xtqqczze]

Potentially caused by #111023. FYI @tannergooding. From range: d551abb...f3d90b2.

Likely, because of a call to implicit operator ReadOnlyMemory<T> (Memory<T> memory), which was changed in #111023:

runtime/src/libraries/System.Private.CoreLib/src/System/IO/Stream.cs

Lines 308 to 313 in 80187a3

	public virtual ValueTask<int> ReadAsync(Memory<byte> buffer, CancellationToken cancellationToken = default)
	{
	if (MemoryMarshal.TryGetArray(buffer, out ArraySegment<byte> array))
	{
	return new ValueTask<int>(ReadAsync(array.Array!, array.Offset, array.Count, cancellationToken));
	}