[Perf] Linux/arm64: 1 Improvement on 7/29/2026 2:14:39 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [a7bb6dfe4ab5ba1804be80698cf138a65e9c0370](https://github.com/dotnet/runtime/commit/a7bb6dfe4ab5ba1804be80698cf138a65e9c0370)
Compare | [ba10a6ee8aa80fce1bb3e40b57b2b941102107c9](https://github.com/dotnet/runtime/commit/ba10a6ee8aa80fce1bb3e40b57b2b941102107c9)
Diff | [Diff](https://github.com/dotnet/runtime/compare/a7bb6dfe4ab5ba1804be80698cf138a65e9c0370...ba10a6ee8aa80fce1bb3e40b57b2b941102107c9)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Collections.CtorDefaultSize<String>

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

• [ConcurrentBag - 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
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Collections.CtorDefaultSize*'
```

### System.Collections.CtorDefaultSize<String>.ConcurrentBag

#### 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 src/benchmarks/micro/libraries/System.Collections/Create/CtorDefaultSize.cs at lines 54-55 and the linked benchmark report. Run the provided benchmarks_ci.py command, then compare the baseline and test results for ConcurrentBag on arm64 AzureLinux. Done means the reported improvement is understood and any follow-up is clearly identified.

Written by the indexing model from the issue text.