[Perf] Linux/arm64: 8 Improvements on 8/7/2026 4:52:16 PM +00:00

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#78,249 opened on Aug 20, 2026 1 comment 0 reactions 0 assignees View on GitHub

ampere arch-arm64 branch-refs/heads/main compilationmode-tiered kind-micro Look Again os-linux perf-improvement runkind-micro runtime-coreclr untriaged

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Forks: 8
PR merge metrics: PR metrics pending

Description

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | ubuntu 22.04
Queue | AmpereUbuntu
Baseline | [9bf3be3ad48e77e97436fa96825cb713a6964389](https://github.com/dotnet/runtime/commit/9bf3be3ad48e77e97436fa96825cb713a6964389)
Compare | [4c86c57ac3a6569063da4cb0a7245aadbc276f00](https://github.com/dotnet/runtime/commit/4c86c57ac3a6569063da4cb0a7245aadbc276f00)
Diff | [Diff](https://github.com/dotnet/runtime/compare/9bf3be3ad48e77e97436fa96825cb713a6964389...4c86c57ac3a6569063da4cb0a7245aadbc276f00)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Collections.IterateForEach<String>

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

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

| 27.92 μs | 20.65 μs | 0.74 | 0.32 | False | | |
|

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

| 14.57 μs | 12.47 μs | 0.86 | 0.34 | False | | |
|

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

| 14.65 μs | 12.58 μs | 0.86 | 0.32 | False | | |
|

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

| 13.24 μs | 11.37 μs | 0.86 | 0.31 | 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.Collections.IterateForEach*'
```

### System.Collections.IterateForEach<String>.ImmutableHashSet(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

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

#### ETL Files

#### Histogram

#### JIT Disasms

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

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Collections.IterateForEach<String>.ImmutableList(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

### Improvements in System.Collections.Sort<Int32>

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

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

| 27.36 μs | 24.22 μs | 0.89 | 0.36 | 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.Sort*'
```

### System.Collections.Sort<Int32>.Array_ComparerStruct(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Improvements in System.Text.Json.Serialization.Tests.WriteJson<ImmutableSortedDictionary<String, String>>

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]()

| 9.02 μs | 8.32 μs | 0.92 | 0.29 | 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.Serialization.Tests.WriteJson>*'
```

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

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Improvements in System.Collections.Sort<IntClass>

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

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

| 49.00 μs | 43.88 μs | 0.90 | 0.27 | 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.Sort*'
```

### System.Collections.Sort<IntClass>.Array_ComparerStruct(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Improvements in System.Collections.Sort<IntStruct>

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

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

| 27.30 μs | 23.71 μs | 0.87 | 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.Sort*'
```

### System.Collections.Sort<IntStruct>.Array_ComparerStruct(Size: 512)

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

Contributor guide

No contributing guide indexed for this repository

Research direction

Start with the benchmark sources src/benchmarks/micro/libraries/System.Collections/Iterate/IterateForEach.cs and System.Collections/Sort.cs, then run the documented benchmarks_ci.py command on Ubuntu arm64. The payload does not define a code change or completion criterion; done would require a confirmed triage outcome for the reported performance results and validation of any resulting change.

Written by the indexing model from the issue text.

Assessment

Tech stack: linux, python
Domain: performance
Issue type: Bug
Difficulty: 5/5
Estimated time: Over a week
Activity status: Active
Clarity: Needs clarification
Newbie friendliness: 25/100

[Perf] Linux/arm64: 8 Improvements on 8/7/2026 4:52:16 PM +00:00

Description

Contributor guide

Research direction

Assessment

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