[Perf] Linux/x64: 2 Regressions on 7/7/2026 1:33:15 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [f2c93f81b35ddc48dd5ad22c759821277db6dfdf](https://github.com/dotnet/sdk/commit/f2c93f81b35ddc48dd5ad22c759821277db6dfdf)
Compare | [a67d575054ff3bcb905ea6699734d0ed8816aa2b](https://github.com/dotnet/sdk/commit/a67d575054ff3bcb905ea6699734d0ed8816aa2b)
Diff | [Diff](https://github.com/dotnet/sdk/compare/f2c93f81b35ddc48dd5ad22c759821277db6dfdf...a67d575054ff3bcb905ea6699734d0ed8816aa2b)
Configs | CompilationMode:tiered, RunKind:akadeindexedset

### Regressions in Akade.IndexedSet.Benchmarks.ConcurrentSetBenchmarks

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

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

| 27.24 ns | 31.57 ns | 1.16 | 0.00 | True | | |
|

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

| 13.89 ns | 15.57 ns | 1.12 | 0.00 | True | | |

![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 'Akade.IndexedSet.Benchmarks.ConcurrentSetBenchmarks*'
```

### Akade.IndexedSet.Benchmarks.ConcurrentSetBenchmarks.ConcurrentLessThanLookup

#### ETL Files

#### Histogram

#### JIT Disasms

### Akade.IndexedSet.Benchmarks.ConcurrentSetBenchmarks.LessThanLookup

#### 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 ConcurrentSetBenchmarks.cs source links and reproduce the reported benchmarks using the provided benchmarks_ci.py command on Ubuntu 22.04. Compare the baseline and test commits, then inspect the linked history, graphs, and test report to determine the cause. Done means the regression is resolved and the affected benchmarks no longer show the reported slowdown.

Written by the indexing model from the issue text.