[Perf] Linux/x64: 8 Regressions on 4/26/2026 11:27:22 AM +00:00

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#72,021 opened on Apr 28, 2026 1 comment 0 reactions 0 assignees View on GitHub

arch-wasm arch-x64 branch-refs/heads/main compilationmode-wasm kind-micro os-linux perf-regression runkind-micro runtimetype-coreclr untriaged

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Forks: 8
PR merge metrics: PR metrics pending

Description

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [932247a4703f30a573f3efbe680a5bc649b7b4ef](https://github.com/dotnet/runtime/commit/932247a4703f30a573f3efbe680a5bc649b7b4ef)
Compare | [a9bbe530c25e60e1da9cf29f3646062498d69b28](https://github.com/dotnet/runtime/commit/a9bbe530c25e60e1da9cf29f3646062498d69b28)
Diff | [Diff](https://github.com/dotnet/runtime/compare/932247a4703f30a573f3efbe680a5bc649b7b4ef...a9bbe530c25e60e1da9cf29f3646062498d69b28)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in System.Linq.Tests.Perf_Enumerable

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

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

| 79.31 μs | 94.80 μs | 1.20 | 0.22 | False | | |
|

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

| 16.86 μs | 19.25 μs | 1.14 | 0.23 | 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.Linq.Tests.Perf_Enumerable*'
```

### System.Linq.Tests.Perf_Enumerable.GroupBy(input: IEnumerable)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Linq.Tests.Perf_Enumerable.TakeLastHalf(input: List)

#### 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

### Regressions in PerfLabTests.CastingPerf

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

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

| 513.73 ns | 2061.82 ns | 4.01 | 0.35 | False | | |
|

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

| 97.27 ms | 224.38 ms | 2.31 | 0.29 | 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 'PerfLabTests.CastingPerf*'
```

### PerfLabTests.CastingPerf.CheckListIsVariantGenericInterface

#### ETL Files

#### Histogram

#### JIT Disasms

### PerfLabTests.CastingPerf.ObjObjIsFoo

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

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

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

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

| 14.49 ms | 17.23 ms | 1.19 | 0.37 | 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.ContainsTrueComparer*'
```

### System.Collections.ContainsTrueComparer<String>.SortedSet(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Collections.CtorFromCollection<Int32>

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

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

| 6.71 μs | 8.39 μs | 1.25 | 0.23 | 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.CtorFromCollection*'
```

### System.Collections.CtorFromCollection<Int32>.Stack(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in MicroBenchmarks.Serializers.Xml_ToStream<CollectionsOfPrimitives>

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

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

| 15.99 ms | 18.39 ms | 1.15 | 0.28 | 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 'MicroBenchmarks.Serializers.Xml_ToStream*'
```

### MicroBenchmarks.Serializers.Xml_ToStream<CollectionsOfPrimitives>.DataContractSerializer_BinaryXml_

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Linq.Tests.Perf_OrderBy

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

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

| 4.74 ms | 5.43 ms | 1.15 | 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.Linq.Tests.Perf_OrderBy*'
```

### System.Linq.Tests.Perf_OrderBy.OrderByCustomComparer(NumberOfPeople: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

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[Perf] Linux/x64: 8 Regressions on 4/26/2026 11:27:22 AM +00:00

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