[Perf] Linux/x64: 2 Regressions on 8/4/2026 3:42:07 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [80aa3f8c5a2d33664fbedafd2f2bb18fdeb8002f](https://github.com/dotnet/runtime/commit/80aa3f8c5a2d33664fbedafd2f2bb18fdeb8002f)
Compare | [173e6b40e02cd1652102c09e07bd4cf7320b3d4d](https://github.com/dotnet/runtime/commit/173e6b40e02cd1652102c09e07bd4cf7320b3d4d)
Diff | [Diff](https://github.com/dotnet/runtime/compare/80aa3f8c5a2d33664fbedafd2f2bb18fdeb8002f...173e6b40e02cd1652102c09e07bd4cf7320b3d4d)
Configs | AOT:true, CompilationMode:wasm, RunKind:micro

### Regressions in System.Buffers.Tests.ReadOnlySequenceTests<Byte>

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

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

| 57.06 ns | 63.48 ns | 1.11 | 0.05 | 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.Buffers.Tests.ReadOnlySequenceTests*'
```

### System.Buffers.Tests.ReadOnlySequenceTests<Byte>.SliceMemory

#### 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 | [80aa3f8c5a2d33664fbedafd2f2bb18fdeb8002f](https://github.com/dotnet/runtime/commit/80aa3f8c5a2d33664fbedafd2f2bb18fdeb8002f)
Compare | [f107b2325cccfd453f9bf46013159f4704ea56c2](https://github.com/dotnet/runtime/commit/f107b2325cccfd453f9bf46013159f4704ea56c2)
Diff | [Diff](https://github.com/dotnet/runtime/compare/80aa3f8c5a2d33664fbedafd2f2bb18fdeb8002f...f107b2325cccfd453f9bf46013159f4704ea56c2)
Configs | AOT:true, CompilationMode:wasm, RunKind:micro

### Regressions in System.Reflection.Attributes

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

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

| 533.56 ns | 584.42 ns | 1.10 | 0.08 | 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.Reflection.Attributes*'
```

### System.Reflection.Attributes.IsDefinedMethodBaseMissInherit

#### 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 listed benchmark sources, src/benchmarks/micro/libraries/System.Buffers/ReadOnlySequenceTests.cs and src/benchmarks/micro/runtime/System.Reflection/Attributes.cs, then review the baseline and comparison commits. Run the provided benchmarks_ci.py commands and compare the reported measurements and test reports. Done means both regressions are reproduced and their relationship to the listed commit ranges is documented.

Written by the indexing model from the issue text.