[Perf] Linux/x64: 1 Regression on 9/6/2026 6:55:28 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [134de00ac5934568c582a35322ae16a228db430d](https://github.com/dotnet/runtime/commit/134de00ac5934568c582a35322ae16a228db430d)
Compare | [570fcdab16c5b674bb59007f4faa705671d69cc2](https://github.com/dotnet/runtime/commit/570fcdab16c5b674bb59007f4faa705671d69cc2)
Diff | [Diff](https://github.com/dotnet/runtime/compare/134de00ac5934568c582a35322ae16a228db430d...570fcdab16c5b674bb59007f4faa705671d69cc2)
Configs | CompilationMode:wasm, RunKind:micro

### Regressions in System.IO.Tests.Perf_RandomAccess

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

• [ReadScatter - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config 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.IO.Tests.Perf_RandomAccess*'
```

### System.IO.Tests.Perf_RandomAccess.ReadScatter(fileSize: 104857600, buffersSize: 65536, options: Asynchronous)

#### 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 System.IO.Tests.Perf_RandomAccess.ReadScatter benchmark at src/benchmarks/micro/libraries/System.IO.FileSystem/Perf.RandomAccess.cs#L157-L174 and reproduce it using the provided benchmarks_ci.py command. Compare the reported 12.42 ms result with the 10.62 ms baseline, then identify the regression cause and verify that the benchmark no longer regresses.

Written by the indexing model from the issue text.