[Perf] Linux/x64: 2 Regressions on 7/31/2026 2:45:28 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [fdccdc6954791fcde7ffa2834d75930c0efa5456](https://github.com/dotnet/runtime/commit/fdccdc6954791fcde7ffa2834d75930c0efa5456)
Compare | [ba8afceee83540ed1d867987483f74d4ad2cfae9](https://github.com/dotnet/runtime/commit/ba8afceee83540ed1d867987483f74d4ad2cfae9)
Diff | [Diff](https://github.com/dotnet/runtime/compare/fdccdc6954791fcde7ffa2834d75930c0efa5456...ba8afceee83540ed1d867987483f74d4ad2cfae9)
Configs | AOT:true, CompilationMode:wasm, RunKind:micro

### Regressions in System.Text.Json.Tests.Utf8JsonReaderCommentsTests

Benchmark | Baseline | Test | Test/Base | Test Quality | Edge Detector | Baseline IR | Compare IR | IR Ratio
-- | -- | -- | -- | -- | -- | -- | -- | --
|

• [Utf8JsonReaderCommentParsing - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 118.71 ns | 152.30 ns | 1.28 | 0.13 | False | | |
|

• [Utf8JsonReaderCommentParsing - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 114.56 ns | 135.44 ns | 1.18 | 0.17 | False | | |

![graph]()
![graph]()
[Test Report]()

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

```cmd
git clone https://github.com/dotnet/performance.git
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Text.Json.Tests.Utf8JsonReaderCommentsTests*'
```

### System.Text.Json.Tests.Utf8JsonReaderCommentsTests.Utf8JsonReaderCommentParsing(CommentHandling: Allow, SegmentSize: 0, TestCase: ShortMultiLine)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Utf8JsonReaderCommentsTests.Utf8JsonReaderCommentParsing(CommentHandling: Skip, SegmentSize: 0, TestCase: ShortSingleLine)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

[Profiling workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/profiling-workflow-dotnet-runtime.md)
[Benchmarking workflow for dotnet/runtime repository](https://github.com/dotnet/performance/blob/master/docs/benchmarking-workflow-dotnet-runtime.md)

Start with the benchmark source at performance/src/benchmarks/micro/libraries/System.Text.Json/Utf8JsonReader/Utf8JsonReader.Comments.Tests.cs#L51-L62 and the baseline/compare commits. Follow the benchmarking workflow and run the supplied benchmarks_ci.py command for the System.Text.Json.Tests.Utf8JsonReaderCommentsTests filter. Done means the two AOT/Wasm regressions are reproduced and explained, with the issue addressed or documented as not actionable.

Written by the indexing model from the issue text.