[Perf] Linux/arm64: 2 Improvements on 7/14/2026 1:02:26 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [f2b30309fd488f1c3fd41c18723a7c80a81f4c67](https://github.com/dotnet/runtime/commit/f2b30309fd488f1c3fd41c18723a7c80a81f4c67)
Compare | [6d47555c87f335445a547d00da9cd7a2034d94ce](https://github.com/dotnet/runtime/commit/6d47555c87f335445a547d00da9cd7a2034d94ce)
Diff | [Diff](https://github.com/dotnet/runtime/compare/f2b30309fd488f1c3fd41c18723a7c80a81f4c67...6d47555c87f335445a547d00da9cd7a2034d94ce)
Configs | CompilationMode:tiered, R2RType:r2r_interpreter, RunKind:micro

### Improvements in System.IO.Tests.Perf_RandomAccess

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

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

| 265.19 ms | 230.16 ms | 0.87 | 0.76 | 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.IO.Tests.Perf_RandomAccess*'
```

### System.IO.Tests.Perf_RandomAccess.WriteAsync(fileSize: 104857600, bufferSize: 16384, options: None)

#### 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 | [f2b30309fd488f1c3fd41c18723a7c80a81f4c67](https://github.com/dotnet/runtime/commit/f2b30309fd488f1c3fd41c18723a7c80a81f4c67)
Compare | [6d47555c87f335445a547d00da9cd7a2034d94ce](https://github.com/dotnet/runtime/commit/6d47555c87f335445a547d00da9cd7a2034d94ce)
Diff | [Diff](https://github.com/dotnet/runtime/compare/f2b30309fd488f1c3fd41c18723a7c80a81f4c67...6d47555c87f335445a547d00da9cd7a2034d94ce)
Configs | CompilationMode:tiered, R2RType:r2r_interpreter, RunKind:micro

### Improvements in System.Net.Http.Tests.SocketsHttpHandlerPerfTest

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

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

| 219.61 μs | 179.35 μs | 0.82 | 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
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Net.Http.Tests.SocketsHttpHandlerPerfTest*'
```

### System.Net.Http.Tests.SocketsHttpHandlerPerfTest.Get(ssl: True, chunkedResponse: False, responseLength: 1)

#### 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 at src/benchmarks/micro/libraries/System.IO.FileSystem/Perf.RandomAccess.cs#L129-L145 and src/benchmarks/micro/libraries/System.Net.Http/Perf.SocketsHttpHandler.cs#L95-L107. Run the two benchmarks using the provided benchmarks_ci.py commands, then review the linked test reports and profiling workflow. Done requires identifying and addressing the cause of the reported Linux/arm64 performance changes, but the issue does not specify an expected code change.

Written by the indexing model from the issue text.