[Perf] Linux/arm64: 2 Improvements on 6/25/2026 8:43:50 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [cd27dcec16016aa54be6a09962d1b509150cf99b](https://github.com/dotnet/runtime/commit/cd27dcec16016aa54be6a09962d1b509150cf99b)
Compare | [d6c7fb69f882c3ffd49de58dd009330e2a915402](https://github.com/dotnet/runtime/commit/d6c7fb69f882c3ffd49de58dd009330e2a915402)
Diff | [Diff](https://github.com/dotnet/runtime/compare/cd27dcec16016aa54be6a09962d1b509150cf99b...d6c7fb69f882c3ffd49de58dd009330e2a915402)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Text.Json.Tests.Perf_Deep

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

• [WriteDeepUtf16 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 28.76 ms | 24.47 ms | 0.85 | 0.28 | False | | |
|

• [WriteDeepUtf8 - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config Graph]()

| 4.18 ms | 3.87 ms | 0.93 | 0.19 | 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
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Text.Json.Tests.Perf_Deep*'
```

### System.Text.Json.Tests.Perf_Deep.WriteDeepUtf16(Formatted: True, SkipValidation: True)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Deep.WriteDeepUtf8(Formatted: False, SkipValidation: True)

#### 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 linked benchmark source, performance/src/benchmarks/micro/libraries/System.Text.Json/Utf8JsonWriter/Perf.Deep.cs, and run the documented benchmarks_ci.py command for System.Text.Json.Tests.Perf_Deep. Compare the arm64 AzureLinux results and reports; done is not defined because the issue records improvements rather than requesting a specific change.

Written by the indexing model from the issue text.