[Perf] Linux/x64: 19 Regressions on 4/28/2026 6:34:45 PM +00:00

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#72,188 opened on Apr 30, 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 | [2e4f24bdff2049c533e89260fc74a45ed27fe309](https://github.com/dotnet/runtime/commit/2e4f24bdff2049c533e89260fc74a45ed27fe309)
Compare | [5391e9ec4fb4ab1bcebe4dbfc33bf4b8fdf01981](https://github.com/dotnet/runtime/commit/5391e9ec4fb4ab1bcebe4dbfc33bf4b8fdf01981)
Diff | [Diff](https://github.com/dotnet/runtime/compare/2e4f24bdff2049c533e89260fc74a45ed27fe309...5391e9ec4fb4ab1bcebe4dbfc33bf4b8fdf01981)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in System.Numerics.Tests.Perf_VectorOf<SByte>

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

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

| 588.30 ns | 775.80 ns | 1.32 | 0.33 | False | | |
|

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

| 7.00 μs | 8.75 μs | 1.25 | 0.35 | False | | |
|

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

| 2.03 μs | 2.42 μs | 1.19 | 0.33 | False | | |
|

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

| 7.18 μs | 8.15 μs | 1.14 | 0.31 | False | | |
|

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

| 7.61 μs | 8.62 μs | 1.13 | 0.35 | False | | |
|

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

| 1.94 μs | 2.11 μs | 1.09 | 0.31 | False | | |

![graph]()
![graph]()
![graph]()
![graph]()
![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.Numerics.Tests.Perf_VectorOf*'
```

### System.Numerics.Tests.Perf_VectorOf<SByte>.InequalityOperatorBenchmark

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Numerics.Tests.Perf_VectorOf<SByte>.GreaterThanBenchmark

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Numerics.Tests.Perf_VectorOf<SByte>.BitwiseAndBenchmark

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Numerics.Tests.Perf_VectorOf<SByte>.GreaterThanOrEqualBenchmark

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Numerics.Tests.Perf_VectorOf<SByte>.MinBenchmark

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Numerics.Tests.Perf_VectorOf<SByte>.ExclusiveOrOperatorBenchmark

#### 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 System.Runtime.Intrinsics.Tests.Perf_Vector128Float

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

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

| 2.84 μs | 3.14 μs | 1.11 | 0.32 | False | | |
|

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

| 920.73 ns | 1007.04 ns | 1.09 | 0.39 | False | | |
|

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

| 2.57 μs | 2.77 μs | 1.08 | 0.26 | False | | |
|

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

| 2.54 μs | 2.72 μs | 1.07 | 0.27 | False | | |

![graph]()
![graph]()
![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.Runtime.Intrinsics.Tests.Perf_Vector128Float*'
```

### System.Runtime.Intrinsics.Tests.Perf_Vector128Float.MinBenchmark

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Runtime.Intrinsics.Tests.Perf_Vector128Float.XorBenchmark

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Runtime.Intrinsics.Tests.Perf_Vector128Float.LessThanOrEqualBenchmark

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Runtime.Intrinsics.Tests.Perf_Vector128Float.DivideBenchmark

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.IO.Tests.Perf_File

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

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

| 179.87 μs | 195.36 μs | 1.09 | 0.17 | False | | |
|

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

| 43.95 μs | 46.58 μs | 1.06 | 0.15 | 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.IO.Tests.Perf_File*'
```

### System.IO.Tests.Perf_File.AppendAllLines

#### ETL Files

#### Histogram

#### JIT Disasms

### System.IO.Tests.Perf_File.ReadAllBytes(size: 4096)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Text.Json.Serialization.Tests.WriteJson<ClassRecord>

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

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

| 31.12 μs | 36.98 μs | 1.19 | 0.39 | False | | |
|

[SerializeToUtf8Bytes - Duration of single invocation]()
📝 - [Benchmark Source]()
[ADX - Test Multi Config Graph]()

| 56.64 μs | 61.81 μs | 1.09 | 0.26 | 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.Serialization.Tests.WriteJson*'
```

### System.Text.Json.Serialization.Tests.WriteJson<ClassRecord>.SerializeToWriter(Mode: SourceGen)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Serialization.Tests.WriteJson<ClassRecord>.SerializeToUtf8Bytes(Mode: Reflection)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Collections.Tests.Perf_Dictionary

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

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

| 417.52 μs | 572.35 μs | 1.37 | 0.47 | 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.Tests.Perf_Dictionary*'
```

### System.Collections.Tests.Perf_Dictionary.Clone(Items: 3000)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.IO.Tests.BinaryReaderTests

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

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

| 9.73 μs | 10.59 μs | 1.09 | 0.24 | 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.IO.Tests.BinaryReaderTests*'
```

### System.IO.Tests.BinaryReaderTests.ReadNonAsciiChar

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in MicroBenchmarks.Serializers.Json_FromStream<Location>

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

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

| 177.69 μs | 204.75 μs | 1.15 | 0.22 | 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.Json_FromStream*'
```

### MicroBenchmarks.Serializers.Json_FromStream<Location>.JsonNet_

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

| 30.74 ms | 43.78 ms | 1.42 | 0.42 | 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_

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Text.Json.Tests.Perf_Guids

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

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

| 489.17 ms | 591.65 ms | 1.21 | 0.35 | 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.Text.Json.Tests.Perf_Guids*'
```

### System.Text.Json.Tests.Perf_Guids.WriteGuids(Formatted: True, SkipValidation: True)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

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[Perf] Linux/x64: 19 Regressions on 4/28/2026 6:34:45 PM +00:00

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