dotnet / dotnet/perf-autofiling-issues

[Perf] Windows/x86: 29 Regressions on 7/14/2026 4:54:43 PM +00:00

Open
#76,530 2 comments 0 reactions 0 assignees View on GitHub
arch-x86 branch-refs/heads/main compilationmode-tiered kind-micro os-windows perf-regression runkind-micro runtime-coreclr triage-error untriaged
Dominant language
No language data
Stars
10
Forks
8
PR metrics pending

Description

### Run Information

Name | Value
-- | --
Architecture | x86
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [f2b30309fd488f1c3fd41c18723a7c80a81f4c67](https://github.com/dotnet/runtime/commit/f2b30309fd488f1c3fd41c18723a7c80a81f4c67)
Compare | [646ab80e65fcf3cb9f068157f644ead63761ee7c](https://github.com/dotnet/runtime/commit/646ab80e65fcf3cb9f068157f644ead63761ee7c)
Diff | [Diff](https://github.com/dotnet/runtime/compare/f2b30309fd488f1c3fd41c18723a7c80a81f4c67...646ab80e65fcf3cb9f068157f644ead63761ee7c)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions in System.Text.Json.Tests.Perf_Segment

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

  • [ReadSingleSegmentSequenceByN - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 4.76 μs | 5.56 μs | 1.17 | 0.03 | False | | |
|
  • [ReadSingleSegmentSequence - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 4.73 μs | 5.41 μs | 1.14 | 0.03 | False | | |
|
  • [ReadMultiSegmentSequence - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 4.73 μs | 5.37 μs | 1.14 | 0.01 | False | | |
|
  • [ReadMultiSegmentSequenceUsingSpan - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 488.04 μs | 554.43 μs | 1.14 | 0.03 | False | | |
|
  • [ReadSingleSegmentSequenceByN - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 4.81 μs | 5.46 μs | 1.14 | 0.03 | False | | |
|
  • [ReadSingleSegmentSequenceByN - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 484.48 μs | 545.60 μs | 1.13 | 0.03 | False | | |
|
  • [ReadMultiSegmentSequenceUsingSpan - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 494.62 μs | 555.65 μs | 1.12 | 0.02 | False | | |
|
  • [ReadSingleSegmentSequenceByN - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 47.90 μs | 53.81 μs | 1.12 | 0.01 | False | | |
|
  • [ReadMultiSegmentSequenceUsingSpan - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 49.90 μs | 55.96 μs | 1.12 | 0.04 | False | | |
|
  • [ReadMultiSegmentSequenceUsingSpan - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 4.91 μs | 5.49 μs | 1.12 | 0.01 | False | | |
|
  • [ReadSingleSegmentSequenceByN - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 48.27 μs | 53.91 μs | 1.12 | 0.02 | False | | |
|
  • [ReadMultiSegmentSequenceUsingSpan - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 48.85 μs | 54.43 μs | 1.11 | 0.05 | False | | |
|
  • [ReadSingleSegmentSequence - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 47.51 μs | 52.52 μs | 1.11 | 0.02 | False | | |
|
  • [ReadSingleSegmentSequence - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 480.70 μs | 526.99 μs | 1.10 | 0.02 | False | | |
|
  • [ReadSingleSegmentSequenceByN - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 502.00 μs | 538.94 μs | 1.07 | 0.02 | False | | |
|
  • [ReadMultiSegmentSequence - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 50.75 μs | 54.12 μs | 1.07 | 0.02 | False | | |
|
  • [ReadMultiSegmentSequence - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 50.62 μs | 53.92 μs | 1.07 | 0.00 | False | | |
|
  • [ReadMultiSegmentSequence - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 513.36 μs | 546.42 μs | 1.06 | 0.03 | False | | |

![graph]()
![graph]()
![graph]()
![graph]()
![graph]()
![graph]()
![graph]()
![graph]()
![graph]()
![graph]()
![graph]()
![graph]()
![graph]()
![graph]()
![graph]()
![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
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Text.Json.Tests.Perf_Segment*'
```

### System.Text.Json.Tests.Perf_Segment.ReadSingleSegmentSequenceByN(numberOfBytes: 8192, TestCase: Json4KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadSingleSegmentSequence(TestCase: Json4KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadMultiSegmentSequence(segmentSize: 8192, TestCase: Json4KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadMultiSegmentSequenceUsingSpan(segmentSize: 8192, TestCase: Json400KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadSingleSegmentSequenceByN(numberOfBytes: 4096, TestCase: Json4KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadSingleSegmentSequenceByN(numberOfBytes: 4096, TestCase: Json400KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadMultiSegmentSequenceUsingSpan(segmentSize: 4096, TestCase: Json400KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadSingleSegmentSequenceByN(numberOfBytes: 8192, TestCase: Json40KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadMultiSegmentSequenceUsingSpan(segmentSize: 4096, TestCase: Json40KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadMultiSegmentSequenceUsingSpan(segmentSize: 4096, TestCase: Json4KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadSingleSegmentSequenceByN(numberOfBytes: 4096, TestCase: Json40KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadMultiSegmentSequenceUsingSpan(segmentSize: 8192, TestCase: Json40KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadSingleSegmentSequence(TestCase: Json40KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadSingleSegmentSequence(TestCase: Json400KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadSingleSegmentSequenceByN(numberOfBytes: 8192, TestCase: Json400KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadMultiSegmentSequence(segmentSize: 4096, TestCase: Json40KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadMultiSegmentSequence(segmentSize: 8192, TestCase: Json40KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Tests.Perf_Segment.ReadMultiSegmentSequence(segmentSize: 4096, TestCase: Json400KB)

#### 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 | x86
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [1baa904ac12c971494469fc724fb3b9f7126716d](https://github.com/dotnet/runtime/commit/1baa904ac12c971494469fc724fb3b9f7126716d)
Compare | [646ab80e65fcf3cb9f068157f644ead63761ee7c](https://github.com/dotnet/runtime/commit/646ab80e65fcf3cb9f068157f644ead63761ee7c)
Diff | [Diff](https://github.com/dotnet/runtime/compare/1baa904ac12c971494469fc724fb3b9f7126716d...646ab80e65fcf3cb9f068157f644ead63761ee7c)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions in System.Text.Json.Document.Tests.Perf_DocumentParse

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

  • [Parse - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 866.36 ns | 966.64 ns | 1.12 | 0.02 | False | | |
|
  • [Parse - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 962.31 ns | 1068.47 ns | 1.11 | 0.03 | False | | |
|
  • [Parse - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 143.37 ns | 156.91 ns | 1.09 | 0.05 | False | | |
|
  • [Parse - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 117.50 ns | 126.37 ns | 1.08 | 0.07 | False | | |
|
  • [Parse - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 627.74 μs | 672.31 μs | 1.07 | 0.02 | False | | |
|
  • [Parse - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 1.31 μs | 1.40 μs | 1.07 | 0.02 | False | | |
|
  • [Parse - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 190.28 ns | 203.01 ns | 1.07 | 0.02 | False | | |
|
  • [Parse - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 1.89 μs | 2.01 μs | 1.07 | 0.02 | False | | |

![graph]()
![graph]()
![graph]()
![graph]()
![graph]()
![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
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Text.Json.Document.Tests.Perf_DocumentParse*'
```

### System.Text.Json.Document.Tests.Perf_DocumentParse.Parse(IsDataIndented: True, TestRandomAccess: False, TestCase: BasicJson)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Document.Tests.Perf_DocumentParse.Parse(IsDataIndented: True, TestRandomAccess: False, TestCase: Json400B)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Document.Tests.Perf_DocumentParse.Parse(IsDataIndented: True, TestRandomAccess: False, TestCase: HelloWorld)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Document.Tests.Perf_DocumentParse.Parse(IsDataIndented: False, TestRandomAccess: False, TestCase: HelloWorld)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Document.Tests.Perf_DocumentParse.Parse(IsDataIndented: True, TestRandomAccess: False, TestCase: Json400KB)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Document.Tests.Perf_DocumentParse.Parse(IsDataIndented: True, TestRandomAccess: True, TestCase: BasicJson)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Document.Tests.Perf_DocumentParse.Parse(IsDataIndented: True, TestRandomAccess: True, TestCase: HelloWorld)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Document.Tests.Perf_DocumentParse.Parse(IsDataIndented: True, TestRandomAccess: True, TestCase: Json400B)

#### 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 | x86
OS | Windows 10.0.22631
Queue | ViperWindows
Baseline | [1baa904ac12c971494469fc724fb3b9f7126716d](https://github.com/dotnet/runtime/commit/1baa904ac12c971494469fc724fb3b9f7126716d)
Compare | [646ab80e65fcf3cb9f068157f644ead63761ee7c](https://github.com/dotnet/runtime/commit/646ab80e65fcf3cb9f068157f644ead63761ee7c)
Diff | [Diff](https://github.com/dotnet/runtime/compare/1baa904ac12c971494469fc724fb3b9f7126716d...646ab80e65fcf3cb9f068157f644ead63761ee7c)
Configs | CompilationMode:tiered, RunKind:micro

### Regressions in System.Text.Json.Document.Tests.Perf_ParseThenWrite

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

  • [ParseThenWrite - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 4.28 μs | 4.75 μs | 1.11 | 0.04 | False | | |
|
  • [ParseThenWrite - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 1.59 μs | 1.70 μs | 1.07 | 0.03 | False | | |
|
  • [ParseThenWrite - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 16.83 μs | 18.02 μs | 1.07 | 0.02 | 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
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Text.Json.Document.Tests.Perf_ParseThenWrite*'
```

### System.Text.Json.Document.Tests.Perf_ParseThenWrite.ParseThenWrite(IsDataIndented: True, TestCase: LotsOfNumbers)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Document.Tests.Perf_ParseThenWrite.ParseThenWrite(IsDataIndented: True, TestCase: Json400B)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Text.Json.Document.Tests.Perf_ParseThenWrite.ParseThenWrite(IsDataIndented: True, TestCase: BroadTree)

#### 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)

Contributor guide

No contributing guide indexed for this repository

Research direction

Start with the benchmark source at src/benchmarks/micro/libraries/System.Text.Json/Utf8JsonReader/Perf.Segment.cs and compare the Baseline and Compare commits linked in the run information. Reproduce the affected System.Text.Json.Tests.Perf_Segment benchmarks on x86 Windows with the tiered micro configuration, then identify and address the regression across the listed cases.

Written by the indexing model from the issue text.

Assessment

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

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.