[Perf] Linux/x64: 2 Regressions on 8/22/2026 9:12:18 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [19bc97f3dd3ab67c7810e4ab179125b7c6a60641](https://github.com/dotnet/sdk/commit/19bc97f3dd3ab67c7810e4ab179125b7c6a60641)
Compare | [b8c18a5c2f5d06efdd635120822953728b21678e](https://github.com/dotnet/sdk/commit/b8c18a5c2f5d06efdd635120822953728b21678e)
Diff | [Diff](https://github.com/dotnet/sdk/compare/19bc97f3dd3ab67c7810e4ab179125b7c6a60641...b8c18a5c2f5d06efdd635120822953728b21678e)
Configs | CompilationMode:tiered, RunKind:bepuphysics

### Regressions in DemoBenchmarks.TwoBodyConstraintBenchmarks

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

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

| 82.95 μs | 91.82 μs | 1.11 | 0.00 | True | | |

![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 'DemoBenchmarks.TwoBodyConstraintBenchmarks*'
```

### DemoBenchmarks.TwoBodyConstraintBenchmarks.DistanceServo

#### 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 | [19bc97f3dd3ab67c7810e4ab179125b7c6a60641](https://github.com/dotnet/sdk/commit/19bc97f3dd3ab67c7810e4ab179125b7c6a60641)
Compare | [b8c18a5c2f5d06efdd635120822953728b21678e](https://github.com/dotnet/sdk/commit/b8c18a5c2f5d06efdd635120822953728b21678e)
Diff | [Diff](https://github.com/dotnet/sdk/compare/19bc97f3dd3ab67c7810e4ab179125b7c6a60641...b8c18a5c2f5d06efdd635120822953728b21678e)
Configs | CompilationMode:tiered, RunKind:bepuphysics

### Regressions in DemoBenchmarks.GatherScatterBenchmarks

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

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

| 22.83 μs | 37.13 μs | 1.63 | 0.00 | True | | |

![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 'DemoBenchmarks.GatherScatterBenchmarks*'
```

### DemoBenchmarks.GatherScatterBenchmarks.ScatterState

#### 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 by running the provided benchmarks_ci.py command with the DemoBenchmarks.TwoBodyConstraintBenchmarks and DemoBenchmarks.GatherScatterBenchmarks filters. Read the linked source ranges in src/benchmarks/real-world/bepuphysics2/TwoBodyConstraintBenchmarks.cs and GatherScatterBenchmarks.cs, then compare the baseline and test reports. Done means identifying and resolving the cause of both Linux/x64 performance regressions and confirming the benchmarks no longer regress.

Written by the indexing model from the issue text.