[Perf] Linux/x64: 1 Improvement on 1/24/2026 9:23:37 AM +00:00

[performanceautofiler]

Run Information

Name	Value
Architecture	x64
OS	ubuntu 22.04
Queue	ViperUbuntu
Baseline	d7b32678f494ef2ae6a39182c46a8efceadcd6c4
Compare	b68c335619ddcdd7d10b40d49f9e6dfa97e710e5
Diff	Diff
Configs	CompilationMode:tiered, RunKind:imagesharp

Improvements in SixLabors.ImageSharp.Benchmarks.Processing.Rotate

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector	Baseline IR	Compare IR	IR Ratio
DoRotate - Duration of single invocation 📝 - Benchmark Source ADX - Test Multi Config Graph	5.46 ms	4.81 ms	0.88	0.00	True

Test Report

Repro

General Docs link: https://github.com/dotnet/performance/blob/main/docs/benchmarking-workflow-dotnet-runtime.md

git clone https://github.com/dotnet/performance.git
python3 .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'SixLabors.ImageSharp.Benchmarks.Processing.Rotate*'

Details

SixLabors.ImageSharp.Benchmarks.Processing.Rotate.DoRotate

ETL Files

Histogram

JIT Disasms

Docs

Profiling workflow for dotnet/runtime repository
Benchmarking workflow for dotnet/runtime repository

[LoopedBard3]

🔍 Automated Triage Analysis

Summary: Performance improvement of ~12% detected in ImageSharp rotation benchmark, but confidence is limited due to missing historical data (0 prior runs). Commit range lookup failed, preventing specific attribution; repository configuration may need verification (dotnet/sdk vs dotnet/runtime mismatch).

Finding Confidence: 2/5 (analysis accuracy)
Regression Confidence: 0/5 (likelihood of true regression)
Likely Cause: null

📊 Full Analysis (click to expand)

Issue Overview

• Issue: #67884 - [Perf] Linux/x64: 1 Improvement on 1/24/2026 9:23:37 AM +00:00
• Date: 2026-01-24 | Queue: Ubuntu.2204.Amd64.Viper.Perf | OS/Arch: ubuntu 22.04/x64
• Commits: d7b3267 → b68c335 (commit range unavailable)
• Labels: untriaged, perf-improvement, arch-x64, os-linux, runtime-coreclr, kind-imagesharp, branch-10.0
• Historical Data: Missing (0 runs) - No historical performance data available for statistical analysis

Test Analysis

Test Name	Baseline	Compare	Δ%	μ	σ	n	z	Thresh%	Noise?	Assessment
SixLabors.ImageSharp.Benchmarks.Processing.Rotate.DoRotate	5.46 ms	4.81 ms	-12.0%	N/A	N/A	0	N/A	5%	N	Substantial improvement

Legend: μ=mean, σ=stddev, n=runs, z=z-score, Thresh%=adaptive threshold

Finding Confidence: 2/5 - No historical data available (0 prior runs). Classification based solely on percent delta magnitude vs fixed 5% threshold. Unable to compute statistical confidence metrics (z-score, CV, adaptive threshold) without baseline measurements.

Confirmed Improvements

SixLabors.ImageSharp.Benchmarks.Processing.Rotate.DoRotate (-12.0%)

• Delta: 5.46 ms → 4.81 ms (-12.0%, faster)
• Historical Context: No historical data available (n=0); unable to compute μ, σ, or z-score
• Assessment: Substantial improvement beyond 5% fixed threshold, but lacking statistical validation
• Finding Confidence: 2/5 - Limited by absence of historical baseline; magnitude suggests real improvement but unverified
• Improvement Confidence: 3/5 - Delta magnitude (-12%) substantially exceeds noise threshold, but cannot statistically validate without historical runs
• Likely Cause: Unable to determine - commit range lookup failed (comparison not found in dotnet/sdk repository)
  • Affected Areas: [Image Processing / Rotation]
  • Rationale: The benchmark tests image rotation performance in the SixLabors.ImageSharp library. The ~12% improvement suggests optimization in rotation algorithms or underlying memory/CPU operations, but specific commit attribution requires commit diff access.
  • Candidates Considered: None - commit range unavailable due to repository access issues
• Verification Status: Not verified
  • Repository mismatch detected: auto-file data references dotnet/sdk, but ImageSharp benchmarks typically test against dotnet/runtime. Commit lookups failed, preventing detailed attribution analysis.

Open Questions

• Historical Data: Missing entirely (0 runs) - This appears to be the first measurement for this test configuration. Cannot establish baseline variance or historical performance trends.
• Confidence Limitations:
  • No statistical validation possible without historical runs
  • Commit range lookup failed (dotnet/sdk repository returned "comparison not found")
  • Potential repository mismatch (ImageSharp benchmarks vs SDK commits)
  • Unable to identify specific code changes responsible for improvement
• Verification Needed:
  • Collect additional runs to establish statistical baseline
  • Verify repository configuration (dotnet/sdk vs dotnet/runtime)
  • Manual investigation of commit range if repository issue resolved
  • Confirm improvement is reproducible across multiple runs

Recommended Actions

1. Establish Historical Baseline - Run multiple iterations of this test to collect baseline performance data for future statistical analysis
2. Repository Verification - Investigate repository configuration; ImageSharp benchmarks typically run against dotnet/runtime, but auto-file data references dotnet/sdk
3. Improvement Verification - Re-run test on both baseline and compare commits to confirm the ~12% improvement is reproducible and not a measurement artifact
4. Manual Commit Review - If repository access is resolved, manually review commits in range to identify potential optimization candidates

Structured Summary (JSON)

{
  "schemaVersion": "perf-triage-v1",
  "issue": 67884,
  "issueType": "improvement",
  "baselineCommit": "d7b32678f494ef2ae6a39182c46a8efceadcd6c4",
  "compareCommit": "b68c335619ddcdd7d10b40d49f9e6dfa97e710e5",
  "commitRangeSize": null,
  "historicalContext": {
    "runsExamined": 0,
    "missing": true,
    "notes": "No historical data available for this test configuration. This appears to be the first measurement. Cannot compute statistical metrics (z-score, CV, adaptive threshold) without baseline runs."
  },
  "improvements": [
    {
      "test": "SixLabors.ImageSharp.Benchmarks.Processing.Rotate.DoRotate",
      "baseline": 5.464839257777777,
      "compare": 4.810503445833334,
      "percentDelta": -11.97,
      "histMean": null,
      "histStdDev": null,
      "zScore": null,
      "isNoise": false,
      "likelyCommit": null,
      "findingConfidence": 2,
      "findingConfidenceRationale": "No historical data (0 runs) prevents statistical validation. Classification based on magnitude only.",
      "improvementConfidence": 3,
      "improvementConfidenceRationale": "Delta magnitude (-12%) substantially exceeds 5% threshold, suggesting genuine improvement despite lack of statistical validation.",
      "verified": false,
      "bisected": false,
      "bisectionRange": null
    }
  ],
  "regressions": [],
  "nextActions": [
    "Establish historical baseline with multiple test runs",
    "Verify repository configuration (dotnet/sdk vs dotnet/runtime)",
    "Confirm improvement reproducibility",
    "Manual commit review if repository access resolved"
  ],
  "generationNotes": "Commit range lookup failed (comparison not found in dotnet/sdk). Potential repository mismatch: ImageSharp benchmarks typically run against dotnet/runtime, but auto-file data references dotnet/sdk. No historical data available (n=0), limiting analysis to percent delta magnitude. Unable to perform commit attribution or statistical validation."
}

---

Generated by PerfTriageAgent on 2026-01-24 09:25 UTC