[Perf] Linux/x64: 2 Regressions on 6/25/2026 3:50:04 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [818cfd5edcda78ac3eb201af392fd301ab9ad46b](https://github.com/dotnet/runtime/commit/818cfd5edcda78ac3eb201af392fd301ab9ad46b)
Compare | [4e28c96c3bd32ce2811ef7128641e8926874020e](https://github.com/dotnet/runtime/commit/4e28c96c3bd32ce2811ef7128641e8926874020e)
Diff | [Diff](https://github.com/dotnet/runtime/compare/818cfd5edcda78ac3eb201af392fd301ab9ad46b...4e28c96c3bd32ce2811ef7128641e8926874020e)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions 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]()

| 2.15 ms | 2.36 ms | 1.10 | 0.03 | False | | |
|

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

| 2.30 ms | 2.45 ms | 1.07 | 0.06 | 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.Perf_Deep*'
```

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

#### ETL Files

#### Histogram

#### JIT Disasms

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

#### 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)