[Perf] Linux/arm64: 2 Improvements on 6/24/2026 2:33:49 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [f4430a4ba762ef82841ff7a8c340ed8854b2bca9](https://github.com/dotnet/runtime/commit/f4430a4ba762ef82841ff7a8c340ed8854b2bca9)
Compare | [46b72c7c81592b429e062bacebe8d39f17362333](https://github.com/dotnet/runtime/commit/46b72c7c81592b429e062bacebe8d39f17362333)
Diff | [Diff](https://github.com/dotnet/runtime/compare/f4430a4ba762ef82841ff7a8c340ed8854b2bca9...46b72c7c81592b429e062bacebe8d39f17362333)
Configs | CompilationMode:tiered, R2RType:r2r_interpreter, RunKind:micro

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

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

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

| 142.41 ns | 121.71 ns | 0.85 | 0.52 | 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
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Collections.CtorGivenSize*'
```

### System.Collections.CtorGivenSize<Int32>.List(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 | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [f4430a4ba762ef82841ff7a8c340ed8854b2bca9](https://github.com/dotnet/runtime/commit/f4430a4ba762ef82841ff7a8c340ed8854b2bca9)
Compare | [46b72c7c81592b429e062bacebe8d39f17362333](https://github.com/dotnet/runtime/commit/46b72c7c81592b429e062bacebe8d39f17362333)
Diff | [Diff](https://github.com/dotnet/runtime/compare/f4430a4ba762ef82841ff7a8c340ed8854b2bca9...46b72c7c81592b429e062bacebe8d39f17362333)
Configs | CompilationMode:tiered, R2RType:r2r_interpreter, RunKind:micro

### Improvements in System.Buffers.Tests.RentReturnArrayPoolTests<Byte>

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

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

| 3.29 μs | 3.06 μs | 0.93 | 0.46 | 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
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Buffers.Tests.RentReturnArrayPoolTests*'
```

### System.Buffers.Tests.RentReturnArrayPoolTests<Byte>.ProducerConsumer(RentalSize: 4096, ManipulateArray: True, Async: True, UseSharedPool: True)

#### 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 benchmark sources named in src/benchmarks/micro/libraries/System.Collections/Create/CtorGivenSize.cs and src/benchmarks/micro/libraries/System.Buffers/ArrayPoolTests.cs. Run the two benchmarks with the provided benchmarks_ci.py commands and inspect the linked reports against the listed baseline and compare commits. The issue does not define a code change or acceptance criterion, so completion requires determining whether the observed improvements need follow-up.

Written by the indexing model from the issue text.