[Perf] Linux/x64: 1 Regression on 8/5/2026 11:16:49 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [173e6b40e02cd1652102c09e07bd4cf7320b3d4d](https://github.com/dotnet/runtime/commit/173e6b40e02cd1652102c09e07bd4cf7320b3d4d)
Compare | [ecc21b8a08df017dbe4d92e81191a028213d418e](https://github.com/dotnet/runtime/commit/ecc21b8a08df017dbe4d92e81191a028213d418e)
Diff | [Diff](https://github.com/dotnet/runtime/compare/173e6b40e02cd1652102c09e07bd4cf7320b3d4d...ecc21b8a08df017dbe4d92e81191a028213d418e)
Configs | AOT:true, CompilationMode:wasm, RunKind:micro

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

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

• [RentNoReturn - Duration of single invocation]()
• 📝 - [Benchmark Source]()
• [ADX - Test Multi Config 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.Buffers.Tests.NonStandardArrayPoolTests*'
```

### System.Buffers.Tests.NonStandardArrayPoolTests<Byte>.RentNoReturn(RentalSize: 64, 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 source at src/benchmarks/micro/libraries/System.Buffers/ArrayPoolTests.cs#L169-L177 and reproduce the reported RentNoReturn regression using the provided benchmarks_ci.py command. Compare the baseline and regression commits, benchmark report, and available performance data to identify the cause. Done means the regression is explained and the reported performance is restored or an actionable fix is identified.

Written by the indexing model from the issue text.