[Perf] Linux/x64: 3 Improvements on 8/10/2026 1:11:36 PM +00:00

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [98037590c8dd74cf65d3cde986af6d03ba0da2f3](https://github.com/dotnet/runtime/commit/98037590c8dd74cf65d3cde986af6d03ba0da2f3)
Compare | [60108ba66eb7d1d12f595480091b4ad80a24b172](https://github.com/dotnet/runtime/commit/60108ba66eb7d1d12f595480091b4ad80a24b172)
Diff | [Diff](https://github.com/dotnet/runtime/compare/98037590c8dd74cf65d3cde986af6d03ba0da2f3...60108ba66eb7d1d12f595480091b4ad80a24b172)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Formats.Tar.Tests.Perf_TarWriter

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

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

| 1.50 μs | 1.24 μs | 0.83 | 0.03 | False | | |
|

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

| 254.47 ns | 212.93 ns | 0.84 | 0.08 | False | | |
|

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

| 254.01 ns | 216.53 ns | 0.85 | 0.12 | False | | |

![graph]()
![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.Formats.Tar.Tests.Perf_TarWriter*'
```

### System.Formats.Tar.Tests.Perf_TarWriter.PaxTarEntry_WriteEntry

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Formats.Tar.Tests.Perf_TarWriter.UstarTarEntry_WriteEntry

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Formats.Tar.Tests.Perf_TarWriter.GnuTarEntry_WriteEntry

#### 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 in dotnet/performance at src/benchmarks/micro/libraries/System.Formats.Tar/Perf.Tar.cs lines 61-67, 77-83, and 93-99. Run the provided benchmarks_ci.py command for System.Formats.Tar.Tests.Perf_TarWriter and compare the linked reports. Done means identifying whether the reported improvements need a runtime change or only triage.

Written by the indexing model from the issue text.