[Perf] Linux/x64: 2 Regressions on 7/11/2026 1:48:32 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [1b945942604aa94b4717243b6d301a17b7ae41f1](https://github.com/dotnet/runtime/commit/1b945942604aa94b4717243b6d301a17b7ae41f1)
Compare | [7db43828cc273aa164f2247744a43f70555f780f](https://github.com/dotnet/runtime/commit/7db43828cc273aa164f2247744a43f70555f780f)
Diff | [Diff](https://github.com/dotnet/runtime/compare/1b945942604aa94b4717243b6d301a17b7ae41f1...7db43828cc273aa164f2247744a43f70555f780f)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in Microsoft.Extensions.Logging.FormattingOverhead

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

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

| 63.62 μs | 70.90 μs | 1.11 | 0.28 | 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 'Microsoft.Extensions.Logging.FormattingOverhead*'
```

### Microsoft.Extensions.Logging.FormattingOverhead.FourArguments_EnumerableArgument

#### 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 | [1b945942604aa94b4717243b6d301a17b7ae41f1](https://github.com/dotnet/runtime/commit/1b945942604aa94b4717243b6d301a17b7ae41f1)
Compare | [7db43828cc273aa164f2247744a43f70555f780f](https://github.com/dotnet/runtime/commit/7db43828cc273aa164f2247744a43f70555f780f)
Diff | [Diff](https://github.com/dotnet/runtime/compare/1b945942604aa94b4717243b6d301a17b7ae41f1...7db43828cc273aa164f2247744a43f70555f780f)
Configs | CompilationMode:wasm, RunKind:micro, RuntimeType:coreclr

### Regressions in BenchmarksGame.FannkuchRedux_2

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

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

| 5.12 secs | 7.23 secs | 1.41 | 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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'BenchmarksGame.FannkuchRedux_2*'
```

### BenchmarksGame.FannkuchRedux_2.RunBench(n: 10, expectedSum: 73196)

#### 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 src/benchmarks/micro/libraries/Microsoft.Extensions.Logging/FormattingOverheadBenchmark.cs and src/benchmarks/micro/runtime/BenchmarksGame/fannkuch-redux-2.cs, then run the provided benchmarks_ci.py commands for both filters. Compare the reported regressions with the baseline and compare commits to identify the cause. Done means the regressions are explained and the affected benchmark returns to baseline performance.

Written by the indexing model from the issue text.