[Perf] Linux/arm64: 2 Improvements on 5/21/2026 10:24:02 AM +00:00

### Run Information

Name | Value
-- | --
Architecture | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [2a65f102aaad2e0b97bf4554dd510ae57801ae5e](https://github.com/dotnet/runtime/commit/2a65f102aaad2e0b97bf4554dd510ae57801ae5e)
Compare | [b77e008c4bd457ef29c4af17bfc99a7525949185](https://github.com/dotnet/runtime/commit/b77e008c4bd457ef29c4af17bfc99a7525949185)
Diff | [Diff](https://github.com/dotnet/runtime/compare/2a65f102aaad2e0b97bf4554dd510ae57801ae5e...b77e008c4bd457ef29c4af17bfc99a7525949185)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Text.Json.Serialization.Tests.ReadJson<Int32>

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

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

| 335.88 ns | 307.10 ns | 0.91 | 0.18 | 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
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Text.Json.Serialization.Tests.ReadJson*'
```

### System.Text.Json.Serialization.Tests.ReadJson<Int32>.DeserializeFromStream(Mode: SourceGen)

#### 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 | arm64
OS | azurelinux 3.0
Queue | CobaltAzureLinux
Baseline | [2a65f102aaad2e0b97bf4554dd510ae57801ae5e](https://github.com/dotnet/runtime/commit/2a65f102aaad2e0b97bf4554dd510ae57801ae5e)
Compare | [b77e008c4bd457ef29c4af17bfc99a7525949185](https://github.com/dotnet/runtime/commit/b77e008c4bd457ef29c4af17bfc99a7525949185)
Diff | [Diff](https://github.com/dotnet/runtime/compare/2a65f102aaad2e0b97bf4554dd510ae57801ae5e...b77e008c4bd457ef29c4af17bfc99a7525949185)
Configs | CompilationMode:tiered, RunKind:micro

### Improvements in System.Memory.Memory<Byte>

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

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

| 60.81 ns | 56.47 ns | 0.93 | 0.39 | 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
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Memory.Memory*'
```

### System.Memory.Memory<Byte>.ToArray(Size: 512)

#### 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)

The issue points to src/benchmarks/micro/libraries/System.Text.Json/Serializer/ReadJson.cs and src/benchmarks/micro/libraries/System.Memory/Memory.cs. Start by running the two supplied filters through scripts/benchmarks_ci.py, then compare the results with the linked reports and baseline and compare commits. Done means explaining or triaging the reported ARM64 improvements.

Written by the indexing model from the issue text.