dotnet / dotnet/perf-autofiling-issues

[Perf] Linux/x64: 11 Regressions on 8/24/2026 1:18:54 AM +00:00

Open
#78,591 1 comment 0 reactions 0 assignees View on GitHub
arch-wasm arch-x64 branch-refs/heads/main compilationmode-wasm kind-micro Look Again os-linux perf-regression runkind-micro untriaged
Dominant language
No language data
Stars
10
Forks
8
PR metrics pending

Description

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [efc7248c8c8a7aa7ad30a58623ee5284ce462a17](https://github.com/dotnet/runtime/commit/efc7248c8c8a7aa7ad30a58623ee5284ce462a17)
Compare | [d5d5cbcba8af2882afdda08e5b667206c7dbf09a](https://github.com/dotnet/runtime/commit/d5d5cbcba8af2882afdda08e5b667206c7dbf09a)
Diff | [Diff](https://github.com/dotnet/runtime/compare/efc7248c8c8a7aa7ad30a58623ee5284ce462a17...d5d5cbcba8af2882afdda08e5b667206c7dbf09a)
Configs | CompilationMode:wasm, RunKind:micro

### Regressions in System.Memory.Span<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]()
| 46.08 ns | 77.54 ns | 1.68 | 0.13 | False | | |
|
  • [ToArray - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 47.07 ns | 74.13 ns | 1.57 | 0.13 | False | | |
|
  • [ToArray - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 92.15 ns | 118.21 ns | 1.28 | 0.05 | False | | |
|
  • [ToArray - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 451.00 ns | 481.44 ns | 1.07 | 0.03 | False | | |

![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
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.Memory.Span*'
```

### System.Memory.Span<Byte>.ToArray(Size: 4)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Memory.Span<Byte>.ToArray(Size: 33)

#### ETL Files

#### Histogram

#### JIT Disasms

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

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Memory.Span<Byte>.ToArray(Size: 3000)

#### 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 | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [efc7248c8c8a7aa7ad30a58623ee5284ce462a17](https://github.com/dotnet/runtime/commit/efc7248c8c8a7aa7ad30a58623ee5284ce462a17)
Compare | [d5d5cbcba8af2882afdda08e5b667206c7dbf09a](https://github.com/dotnet/runtime/commit/d5d5cbcba8af2882afdda08e5b667206c7dbf09a)
Diff | [Diff](https://github.com/dotnet/runtime/compare/efc7248c8c8a7aa7ad30a58623ee5284ce462a17...d5d5cbcba8af2882afdda08e5b667206c7dbf09a)
Configs | CompilationMode:wasm, RunKind:micro

### Regressions in System.Memory.Span<Char>

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]()
| 50.35 ns | 85.28 ns | 1.69 | 0.16 | False | | |
|
  • [ToArray - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 46.89 ns | 74.23 ns | 1.58 | 0.19 | False | | |
|
  • [ToArray - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 127.08 ns | 155.76 ns | 1.23 | 0.09 | 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.Memory.Span*'
```

### System.Memory.Span<Char>.ToArray(Size: 33)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Memory.Span<Char>.ToArray(Size: 4)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Memory.Span<Char>.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)

---

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [efc7248c8c8a7aa7ad30a58623ee5284ce462a17](https://github.com/dotnet/runtime/commit/efc7248c8c8a7aa7ad30a58623ee5284ce462a17)
Compare | [d5d5cbcba8af2882afdda08e5b667206c7dbf09a](https://github.com/dotnet/runtime/commit/d5d5cbcba8af2882afdda08e5b667206c7dbf09a)
Diff | [Diff](https://github.com/dotnet/runtime/compare/efc7248c8c8a7aa7ad30a58623ee5284ce462a17...d5d5cbcba8af2882afdda08e5b667206c7dbf09a)
Configs | CompilationMode:wasm, RunKind:micro

### Regressions in System.Memory.Span<Int32>

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]()
| 46.98 ns | 74.10 ns | 1.58 | 0.12 | False | | |
|
  • [ToArray - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 57.43 ns | 81.98 ns | 1.43 | 0.11 | False | | |
|
  • [ToArray - Duration of single invocation]()
  • 📝 - [Benchmark Source]()
  • [ADX - Test Multi Config Graph]()
| 193.17 ns | 216.35 ns | 1.12 | 0.05 | 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.Memory.Span*'
```

### System.Memory.Span<Int32>.ToArray(Size: 4)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Memory.Span<Int32>.ToArray(Size: 33)

#### ETL Files

#### Histogram

#### JIT Disasms

### System.Memory.Span<Int32>.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)

---

### Run Information

Name | Value
-- | --
Architecture | x64
OS | ubuntu 22.04
Queue | ViperUbuntu
Baseline | [efc7248c8c8a7aa7ad30a58623ee5284ce462a17](https://github.com/dotnet/runtime/commit/efc7248c8c8a7aa7ad30a58623ee5284ce462a17)
Compare | [d5d5cbcba8af2882afdda08e5b667206c7dbf09a](https://github.com/dotnet/runtime/commit/d5d5cbcba8af2882afdda08e5b667206c7dbf09a)
Diff | [Diff](https://github.com/dotnet/runtime/compare/efc7248c8c8a7aa7ad30a58623ee5284ce462a17...d5d5cbcba8af2882afdda08e5b667206c7dbf09a)
Configs | CompilationMode:wasm, RunKind:micro

### Regressions 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]()
| 99.69 ns | 116.53 ns | 1.17 | 0.05 | 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 '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)

Contributor guide

No contributing guide indexed for this repository

Research direction

Start with src/benchmarks/micro/libraries/System.Memory/Span.cs#L59-L60 and run scripts/benchmarks_ci.py using the documented System.Memory.Span filter. Compare the reported baseline and test commits, then inspect the linked benchmark and test reports to determine the regression scope. Done means the reported WASM microbenchmark regressions are explained and validated against a new benchmark run.

Written by the indexing model from the issue text.

Assessment

Tech stack
python, wasm
Domain
performance, testing
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Active
Clarity
Mostly clear
Newbie friendliness
38/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.