[Perf] Linux/arm64: 1 Improvement on 8/18/2026 11:10:09 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [2eebfbf193bc0be8b44f65c9f94d536cf1c3e699](https://github.com/dotnet/runtime/commit/2eebfbf193bc0be8b44f65c9f94d536cf1c3e699)
Compare | [1f22605f08368b251c9ff73b935a8d7c1df4d174](https://github.com/dotnet/runtime/commit/1f22605f08368b251c9ff73b935a8d7c1df4d174)
Diff | [Diff](https://github.com/dotnet/runtime/compare/2eebfbf193bc0be8b44f65c9f94d536cf1c3e699...1f22605f08368b251c9ff73b935a8d7c1df4d174)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.IO.Tests.Perf_FileStream

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

• [Write - 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
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.IO.Tests.Perf_FileStream*'
```

### System.IO.Tests.Perf_FileStream.Write(fileSize: 1048576, userBufferSize: 4096, options: None)

#### 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 in dotnet/performance at src/benchmarks/micro/libraries/System.IO.FileSystem/Perf.FileStream.cs, especially lines 225-228, and read the linked benchmarking workflow. Run the provided benchmarks_ci.py command, then compare the reported commits and benchmark history. Done means determining whether the improvement is expected and recording a clear triage outcome.

Written by the indexing model from the issue text.