[Perf] Linux/x64: 6 Regressions on 7/30/2026 6:50:50 PM +00:00

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#77,359 opened on Aug 4, 2026 1 comment 0 reactions 0 assignees View on GitHub

arch-wasm arch-x64 branch-refs/heads/main compilationmode-wasm kind-micro os-linux perf-regression runkind-micro untriaged

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Forks: 8
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Description

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [72dac24a0e6fa1047002858a762f36c88e53850b](https://github.com/dotnet/runtime/commit/72dac24a0e6fa1047002858a762f36c88e53850b)
Compare | [640b326fc81d94d410753b67c0f89b166d6666df](https://github.com/dotnet/runtime/commit/640b326fc81d94d410753b67c0f89b166d6666df)
Diff | [Diff](https://github.com/dotnet/runtime/compare/72dac24a0e6fa1047002858a762f36c88e53850b...640b326fc81d94d410753b67c0f89b166d6666df)
Configs | CompilationMode:wasm, RunKind:micro

### Regressions in MicroBenchmarks.Serializers.Xml_FromStream<MyEventsListerViewModel>

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

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

| 7.37 ms | 10.76 ms | 1.46 | 0.10 | 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 'MicroBenchmarks.Serializers.Xml_FromStream*'
```

### MicroBenchmarks.Serializers.Xml_FromStream<MyEventsListerViewModel>.XmlSerializer_

#### 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

### Regressions in MicroBenchmarks.Serializers.Xml_FromStream<SimpleStructWithProperties>

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

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

| 39.12 μs | 42.42 μs | 1.08 | 0.27 | 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 'MicroBenchmarks.Serializers.Xml_FromStream*'
```

### MicroBenchmarks.Serializers.Xml_FromStream<SimpleStructWithProperties>.XmlSerializer_

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in MicroBenchmarks.Serializers.Xml_FromStream<IndexViewModel>

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

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

| 645.28 μs | 975.25 μs | 1.51 | 0.13 | 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 'MicroBenchmarks.Serializers.Xml_FromStream*'
```

### MicroBenchmarks.Serializers.Xml_FromStream<IndexViewModel>.XmlSerializer_

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in MicroBenchmarks.Serializers.Xml_FromStream<LoginViewModel>

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

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

| 37.33 μs | 44.84 μs | 1.20 | 0.21 | 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 'MicroBenchmarks.Serializers.Xml_FromStream*'
```

### MicroBenchmarks.Serializers.Xml_FromStream<LoginViewModel>.XmlSerializer_

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in MicroBenchmarks.Serializers.Xml_FromStream<CollectionsOfPrimitives>

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

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

| 5.14 ms | 9.20 ms | 1.79 | 0.14 | 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 'MicroBenchmarks.Serializers.Xml_FromStream*'
```

### MicroBenchmarks.Serializers.Xml_FromStream<CollectionsOfPrimitives>.XmlSerializer_

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

---

### Run Information

### Regressions in MicroBenchmarks.Serializers.Xml_FromStream<Location>

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

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

| 51.05 μs | 71.94 μs | 1.41 | 0.17 | 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 'MicroBenchmarks.Serializers.Xml_FromStream*'
```

### MicroBenchmarks.Serializers.Xml_FromStream<Location>.XmlSerializer_

#### ETL Files

#### Histogram

#### JIT Disasms

### Docs

Contributor guide

No contributing guide indexed for this repository

Research direction

Start with src/benchmarks/micro/Serializers/Xml_FromStream.cs at lines 42-48 and run the provided benchmarks_ci.py filter for the affected Xml_FromStream cases. Compare the reported baseline and test results for the WASM microbenchmarks, using the linked performance and profiling workflow docs. Done means identifying and resolving the reported regressions, with benchmark results no longer showing the regression.

Written by the indexing model from the issue text.

Assessment

Tech stack: csharp, python, wasm
Domain: performance, testing
Issue type: Bug
Difficulty: 4/5
Estimated time: 3-5 days
Activity status: Quiet
Clarity: Needs clarification
Newbie friendliness: 35/100

[Perf] Linux/x64: 6 Regressions on 7/30/2026 6:50:50 PM +00:00

Description

Contributor guide

Research direction

Assessment

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