[Perf] Linux/x64: 29 Regressions on 6/14/2026 8:59:21 AM +00:00

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#74,752 opened on Jun 18, 2026 4 comments 0 reactions 0 assignees View on GitHub

arch-wasm arch-x64 branch-refs/heads/main compilationmode-wasm kind-micro Look Again 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 | [f36379692fdd0448b5b1276a1a4aa075a0d2c1e0](https://github.com/dotnet/runtime/commit/f36379692fdd0448b5b1276a1a4aa075a0d2c1e0)
Compare | [3a87981877445b58ef3c05851888e24c3558876b](https://github.com/dotnet/runtime/commit/3a87981877445b58ef3c05851888e24c3558876b)
Diff | [Diff](https://github.com/dotnet/runtime/compare/f36379692fdd0448b5b1276a1a4aa075a0d2c1e0...3a87981877445b58ef3c05851888e24c3558876b)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in System.Collections.Tests.Perf_PriorityQueue<String, String>

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

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

| 4.21 ms | 6.02 ms | 1.43 | 0.29 | False | | |
|

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

| 76.04 μs | 101.42 μs | 1.33 | 0.35 | False | | |
|

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

| 710.15 μs | 894.83 μs | 1.26 | 0.31 | False | | |
|

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

| 172.72 ms | 202.90 ms | 1.17 | 0.29 | False | | |
|

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

| 11.80 ms | 13.61 ms | 1.15 | 0.30 | False | | |

![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.Collections.Tests.Perf_PriorityQueue*'
```

### System.Collections.Tests.Perf_PriorityQueue<String, String>.K_Max_Elements(Size: 1000)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Collections.Tests.Perf_PriorityQueue<String, String>.K_Max_Elements(Size: 10)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Collections.Tests.Perf_PriorityQueue<String, String>.K_Max_Elements(Size: 100)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Collections.Tests.Perf_PriorityQueue<String, String>.Dequeue_And_Enqueue(Size: 1000)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Collections.Tests.Perf_PriorityQueue<String, String>.Dequeue_And_Enqueue(Size: 100)

#### 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.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]()

| 8.00 μs | 11.02 μs | 1.38 | 0.23 | False | | |
|

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

| 10.56 μs | 13.09 μs | 1.24 | 0.25 | False | | |
|

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

| 11.74 μs | 13.51 μs | 1.15 | 0.24 | False | | |

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

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

#### ETL Files

#### Histogram

#### JIT Disasms

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

#### ETL Files

#### Histogram

#### JIT Disasms

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

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

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

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]()

| 46.54 ms | 50.56 ms | 1.09 | 0.12 | False | | |
|

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

| 44.30 ms | 47.66 ms | 1.08 | 0.16 | False | | |
|

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

| 45.20 ms | 47.62 ms | 1.05 | 0.15 | False | | |

![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.Text.Json.Serialization.Tests.WriteJson*'
```

### System.Text.Json.Serialization.Tests.WriteJson<MyEventsListerViewModel>.SerializeToWriter(Mode: Reflection)

#### ETL Files

#### Histogram

#### JIT Disasms

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

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Serialization.Tests.WriteJson<MyEventsListerViewModel>.SerializeToUtf8Bytes(Mode: SourceGen)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Tests.Perf_DateTimeOffset

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

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

| 17.78 μs | 20.30 μs | 1.14 | 0.21 | False | | |
|

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

| 14.80 μs | 16.59 μs | 1.12 | 0.20 | False | | |
|

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

| 17.93 μs | 19.21 μs | 1.07 | 0.17 | False | | |

![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.Tests.Perf_DateTimeOffset*'
```

### System.Tests.Perf_DateTimeOffset.ToString(value: 12/30/2017 3:45:22 AM -08:00)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_DateTimeOffset.ToString(format: "G")

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Tests.Perf_DateTimeOffset.ToString(format: null)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in Microsoft.Extensions.Logging.ScopesOverheadBenchmark

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

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

| 5.20 μs | 8.23 μs | 1.58 | 0.31 | False | | |
|

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

| 5.53 μs | 6.09 μs | 1.10 | 0.30 | 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 'Microsoft.Extensions.Logging.ScopesOverheadBenchmark*'
```

### Microsoft.Extensions.Logging.ScopesOverheadBenchmark.NotFiltered_InsideScope(HasISupportLoggingScopeLogger: False, CaptureScopes: True)

#### ETL Files

#### Histogram

#### JIT Disasms

### Microsoft.Extensions.Logging.ScopesOverheadBenchmark.FilteredByLevel_InsideScope(HasISupportLoggingScopeLogger: True, CaptureScopes: True)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Text.Tests.Perf_StringBuilder

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

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

| 342.58 μs | 410.22 μs | 1.20 | 0.18 | False | | |
|

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

| 241.79 μs | 289.34 μs | 1.20 | 0.20 | 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.Tests.Perf_StringBuilder*'
```

### System.Text.Tests.Perf_StringBuilder.Append_ValueTypes_Interpolated

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Tests.Perf_StringBuilder.Append_ValueTypes

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Collections.ContainsFalse<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]()

| 17.42 ms | 22.82 ms | 1.31 | 0.32 | False | | |
|

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

| 22.05 ms | 24.73 ms | 1.12 | 0.30 | 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.ContainsFalse*'
```

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

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Collections.ContainsFalse<String>.ImmutableSortedSet(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Reflection.Attributes

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

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

| 9.62 μs | 11.36 μs | 1.18 | 0.20 | False | | |
|

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

| 9.86 μs | 10.93 μs | 1.11 | 0.17 | 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.Reflection.Attributes*'
```

### System.Reflection.Attributes.IsDefinedMethodOverrideHitInherit

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Reflection.Attributes.IsDefinedMethodOverrideMissInherit

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

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

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

[AddOrUpdate2 - Duration of single invocation]()
📝 - [Benchmark Source]()
[ADX - Test Multi Config Graph]()

| 6.72 ms | 7.60 ms | 1.13 | 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.Collections.Perf_OrderedDictionary*'
```

### System.Collections.Perf_OrderedDictionary<String>.AddOrUpdate2(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in System.Collections.CreateAddAndClear<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]()

| 18.16 ms | 25.29 ms | 1.39 | 0.34 | 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>.SortedSet(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

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

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

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

| 1.62 ms | 1.75 ms | 1.08 | 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.TryAddGiventSize*'
```

### System.Collections.TryAddGiventSize<String>.ConcurrentDictionary(Count: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

Contributor guide

No contributing guide indexed for this repository

Research direction

Start with the linked Perf_PriorityQueue.cs benchmark methods and compare the listed baseline and comparison commits, then follow the benchmarking workflow documented in the issue. Run the provided benchmarks_ci.py command and inspect the regression report; done means the cause is identified and a rerun confirms the affected measurements no longer regress.

Written by the indexing model from the issue text.

Assessment

Tech stack: csharp, python, wasm
Domain: performance, testing
Issue type: Bug
Difficulty: 4/5
Estimated time: 3-5 days
Activity status: Quiet
Clarity: Needs clarification
Newbie friendliness: 38/100

[Perf] Linux/x64: 29 Regressions on 6/14/2026 8:59:21 AM +00:00

Description

Contributor guide

Research direction

Assessment

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