[Perf] Linux/x64: 5 Regressions on 9/12/2026 2:03:45 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [40dac002bce5a8b9b345b3e195530c807e8083d0](https://github.com/dotnet/runtime/commit/40dac002bce5a8b9b345b3e195530c807e8083d0)
Compare | [ea973e7517a629d0c3c75f4879ce279b07f21365](https://github.com/dotnet/runtime/commit/ea973e7517a629d0c3c75f4879ce279b07f21365)
Diff | [Diff](https://github.com/dotnet/runtime/compare/40dac002bce5a8b9b345b3e195530c807e8083d0...ea973e7517a629d0c3c75f4879ce279b07f21365)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in System.Collections.Perf_Frozen<ReferenceType>

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

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

| 18.36 μs | 44.76 μs | 2.44 | 0.33 | False | | |
|

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

| 193.75 μs | 353.46 μs | 1.82 | 0.39 | 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.Collections.Perf_Frozen*'
```

### System.Collections.Perf_Frozen<ReferenceType>.TryGetValue_True(Count: 4)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Collections.Perf_Frozen<ReferenceType>.Contains_True(Count: 64)

#### 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 | [40dac002bce5a8b9b345b3e195530c807e8083d0](https://github.com/dotnet/runtime/commit/40dac002bce5a8b9b345b3e195530c807e8083d0)
Compare | [ea973e7517a629d0c3c75f4879ce279b07f21365](https://github.com/dotnet/runtime/commit/ea973e7517a629d0c3c75f4879ce279b07f21365)
Diff | [Diff](https://github.com/dotnet/runtime/compare/40dac002bce5a8b9b345b3e195530c807e8083d0...ea973e7517a629d0c3c75f4879ce279b07f21365)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in System.Collections.CreateAddAndClear<String>

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

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

| 20.92 ms | 23.22 ms | 1.11 | 0.26 | 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.CreateAddAndClear*'
```

### System.Collections.CreateAddAndClear<String>.ImmutableSortedDictionary(Size: 512)

#### 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 | [40dac002bce5a8b9b345b3e195530c807e8083d0](https://github.com/dotnet/runtime/commit/40dac002bce5a8b9b345b3e195530c807e8083d0)
Compare | [ea973e7517a629d0c3c75f4879ce279b07f21365](https://github.com/dotnet/runtime/commit/ea973e7517a629d0c3c75f4879ce279b07f21365)
Diff | [Diff](https://github.com/dotnet/runtime/compare/40dac002bce5a8b9b345b3e195530c807e8083d0...ea973e7517a629d0c3c75f4879ce279b07f21365)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in System.Diagnostics.Perf_Activity

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

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

| 740.06 μs | 1267.32 μs | 1.71 | 0.32 | 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.Diagnostics.Perf_Activity*'
```

### System.Diagnostics.Perf_Activity.EnumerateActivityTagsLarge

#### 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 | [40dac002bce5a8b9b345b3e195530c807e8083d0](https://github.com/dotnet/runtime/commit/40dac002bce5a8b9b345b3e195530c807e8083d0)
Compare | [ea973e7517a629d0c3c75f4879ce279b07f21365](https://github.com/dotnet/runtime/commit/ea973e7517a629d0c3c75f4879ce279b07f21365)
Diff | [Diff](https://github.com/dotnet/runtime/compare/40dac002bce5a8b9b345b3e195530c807e8083d0...ea973e7517a629d0c3c75f4879ce279b07f21365)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in PerfLabTests.CastingPerf

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

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

| 910.17 ns | 1783.73 ns | 1.96 | 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 'PerfLabTests.CastingPerf*'
```

### PerfLabTests.CastingPerf.CheckArrayIsNonvariantGenericInterface

#### 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 reported benchmark sources in src/benchmarks/micro/libraries/System.Collections/Frozen/Perf_Frozen.cs, CreateAddAndClear.cs, and System.Diagnostics/Perf_Activity.cs, then run the listed benchmarks with scripts/benchmarks_ci.py. Compare the reported baseline and test commits and inspect the linked reports to identify the regression. Done means the affected benchmarks no longer show the reported performance regressions.

Written by the indexing model from the issue text.