[Perf] Linux/x64: 2 Regressions on 9/2/2026 11:01:35 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [600c5b67ae4680acf39f6e85529973930bda4168](https://github.com/dotnet/runtime/commit/600c5b67ae4680acf39f6e85529973930bda4168)
Compare | [399c3eb8ba823f00f9a250de4a3cdbdfb5d18f33](https://github.com/dotnet/runtime/commit/399c3eb8ba823f00f9a250de4a3cdbdfb5d18f33)
Diff | [Diff](https://github.com/dotnet/runtime/compare/600c5b67ae4680acf39f6e85529973930bda4168...399c3eb8ba823f00f9a250de4a3cdbdfb5d18f33)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in System.ComponentModel.Tests.Perf_TypeDescriptorTests

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

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

| 7.29 μs | 8.14 μs | 1.12 | 0.18 | False | | |

![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.ComponentModel.Tests.Perf_TypeDescriptorTests*'
```

### System.ComponentModel.Tests.Perf_TypeDescriptorTests.GetConverter(typeToConvert: typeof(string))

#### 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)

---

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [600c5b67ae4680acf39f6e85529973930bda4168](https://github.com/dotnet/runtime/commit/600c5b67ae4680acf39f6e85529973930bda4168)
Compare | [399c3eb8ba823f00f9a250de4a3cdbdfb5d18f33](https://github.com/dotnet/runtime/commit/399c3eb8ba823f00f9a250de4a3cdbdfb5d18f33)
Diff | [Diff](https://github.com/dotnet/runtime/compare/600c5b67ae4680acf39f6e85529973930bda4168...399c3eb8ba823f00f9a250de4a3cdbdfb5d18f33)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in System.Collections.Perf_SingleCharFrozenDictionary

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

• [ToFrozenDictionary - Duration of single invocation]()
• [ADX - Test Multi Config Graph]()

| 37.93 ms | 45.59 ms | 1.20 | 0.31 | False | | |

![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.Collections.Perf_SingleCharFrozenDictionary*'
```

### System.Collections.Perf_SingleCharFrozenDictionary.ToFrozenDictionary(Count: 10000)

#### 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 at src/benchmarks/micro/libraries/System.ComponentModel.TypeConverter/Perf.TypeDescriptorTests.cs and the two linked regression reports, then compare the listed baseline and comparison commits. Run the provided benchmarks_ci.py filters using the benchmarking workflow; done means the regression cause is identified and the affected benchmark no longer regresses.

Written by the indexing model from the issue text.