[Perf] Linux/x64: 2 Regressions on 3/16/2026 11:49:53 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [2c7ee1937a8bd2f17a8f54d3b54bcaa0956f37f2](https://github.com/dotnet/runtime/commit/2c7ee1937a8bd2f17a8f54d3b54bcaa0956f37f2)
Compare | [fc529276b042443bd335adc6b5a26526e7ac9905](https://github.com/dotnet/runtime/commit/fc529276b042443bd335adc6b5a26526e7ac9905)
Diff | [Diff](https://github.com/dotnet/runtime/compare/2c7ee1937a8bd2f17a8f54d3b54bcaa0956f37f2...fc529276b042443bd335adc6b5a26526e7ac9905)
Configs | AOT:true, CompilationMode:wasm, RunKind:micro

### Regressions in System.IO.MemoryMappedFiles.Tests.Perf_MemoryMappedFile

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

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

| 643.83 μs | 746.29 μs | 1.16 | 0.33 | 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.MemoryMappedFiles.Tests.Perf_MemoryMappedFile*'
```

### System.IO.MemoryMappedFiles.Tests.Perf_MemoryMappedFile.CreateFromFile(capacity: 1000000)

#### 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 | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [2c7ee1937a8bd2f17a8f54d3b54bcaa0956f37f2](https://github.com/dotnet/runtime/commit/2c7ee1937a8bd2f17a8f54d3b54bcaa0956f37f2)
Compare | [fc529276b042443bd335adc6b5a26526e7ac9905](https://github.com/dotnet/runtime/commit/fc529276b042443bd335adc6b5a26526e7ac9905)
Diff | [Diff](https://github.com/dotnet/runtime/compare/2c7ee1937a8bd2f17a8f54d3b54bcaa0956f37f2...fc529276b042443bd335adc6b5a26526e7ac9905)
Configs | AOT:true, CompilationMode:wasm, RunKind:micro

### Regressions in System.IO.Tests.Perf_FileStream

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

• [Write_NoBuffering_PreallocationSize - Duration of single invocation]()
• [ADX - Test Multi Config Graph]()

| 535.68 ms | 617.47 ms | 1.15 | 0.23 | 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.Perf_FileStream*'
```

### System.IO.Tests.Perf_FileStream.Write_NoBuffering_PreallocationSize(fileSize: 104857600, userBufferSize: 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)