[Perf] Linux/arm64: 1 Improvement on 7/9/2026 5:44:46 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [0dc2424cb92416af77d8d38292cdcdffa699bd67](https://github.com/dotnet/runtime/commit/0dc2424cb92416af77d8d38292cdcdffa699bd67)
Compare | [6c5849144dc8a23aa0760080d6f7784fed60da37](https://github.com/dotnet/runtime/commit/6c5849144dc8a23aa0760080d6f7784fed60da37)
Diff | [Diff](https://github.com/dotnet/runtime/compare/0dc2424cb92416af77d8d38292cdcdffa699bd67...6c5849144dc8a23aa0760080d6f7784fed60da37)
Configs | CompilationMode:tiered, R2RType:r2r_interpreter, RunKind:micro

### Improvements in System.Text.Json.Serialization.Tests.WriteJson<SimpleStructWithProperties>

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

• [SerializeToWriter - 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.Text.Json.Serialization.Tests.WriteJson*'
```

### System.Text.Json.Serialization.Tests.WriteJson<SimpleStructWithProperties>.SerializeToWriter(Mode: Reflection)

#### 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 src/benchmarks/micro/libraries/System.Text.Json/Serializer/WriteJson.cs at lines 81-87 and run the provided benchmarks_ci.py command for the WriteJson filter. Compare the arm64 AzureLinux results and reports, then determine whether the recorded improvement corresponds to a runtime change; the payload does not define a specific code change or completion condition.

Written by the indexing model from the issue text.