[Perf] Regression on 8/1/2022 6:03:22 PM

[performanceautofiler]

Run Information

Architecture	x64
OS	Windows 10.0.19042
Baseline	f1de614c74589fe8f682dda39889d189f2522504
Compare	68bd58e0e68b22a3cbcc67a3f1218a6c8f623bcf
Diff	Diff

Regressions in System.Tests.Perf_GC<Char>

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector	Baseline IR	Compare IR	IR Ratio	Baseline ETL	Compare ETL
AllocateUninitializedArray - Duration of single invocation	142.23 ns	162.00 ns	1.14	0.05	False

Test Report

Repro

git clone https://github.com/dotnet/performance.git
py .\performance\scripts\benchmarks_ci.py -f net6.0 --filter 'System.Tests.Perf_GC<Char>*'

Payloads

Baseline
Compare

Histogram

System.Tests.Perf_GC<Char>.AllocateUninitializedArray(length: 10000, pinned: False)

Description of detection logic

IsRegressionChecked: Marked as regression because the three check build points were 0.05 greater than the baseline.
IsImprovementBase: Marked as not an improvement because the compare was not 5% less than the baseline, or the value was too small.
IsRegressionBase: Marked as regression because the compare was 5% greater than the baseline, and the value was not too small.
IsRegressionChecked: Marked as regression because the three check build points were 0.05 greater than the baseline.
IsRegressionWindowed: Marked as regression because 162.0041171183368 > 140.82233369196862.
IsChangePoint: Marked as a change because one of 6/8/2022 9:45:10 AM, 6/23/2022 2:33:56 PM, 8/1/2022 4:16:36 PM, 8/5/2022 10:47:59 PM falls between 7/28/2022 9:13:34 AM and 8/5/2022 10:47:59 PM.
IsRegressionStdDev: Marked as regression because -16.15588523243305 (T) = (0 -155.80685151415716) / Math.Sqrt((18.262167754812662 / (46)) + (12.77726289932357 / (28))) is less than -1.9934635666612892 = MathNet.Numerics.Distributions.StudentT.InvCDF(0, 1, (46) + (28) - 2, .025) and -0.10593337674114203 = (140.88267412027457 - 155.80685151415716) / 140.88267412027457 is less than -0.05.
IsImprovementBase: Marked as not an improvement because the compare was not 5% less than the baseline, or the value was too small.
IsChangeEdgeDetector: Marked not as a regression because Edge Detector said so.

Docs

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

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[DrewScoggins]

Seems related to #72923 @mrsharm

[ghost]

Tagging subscribers to this area: @dotnet/gc
See info in area-owners.md if you want to be subscribed.

Issue Details

---

Run Information

Architecture	x64
OS	Windows 10.0.19042
Baseline	f1de614c74589fe8f682dda39889d189f2522504
Compare	68bd58e0e68b22a3cbcc67a3f1218a6c8f623bcf
Diff	Diff

Regressions in System.Tests.Perf_GC<Char>

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector	Baseline IR	Compare IR	IR Ratio	Baseline ETL	Compare ETL
AllocateUninitializedArray - Duration of single invocation	142.23 ns	162.00 ns	1.14	0.05	False

Test Report

Repro

git clone https://github.com/dotnet/performance.git
py .\performance\scripts\benchmarks_ci.py -f net6.0 --filter 'System.Tests.Perf_GC<Char>*'

Payloads

Baseline
Compare

Histogram

System.Tests.Perf_GC<Char>.AllocateUninitializedArray(length: 10000, pinned: False)

Description of detection logic

IsRegressionChecked: Marked as regression because the three check build points were 0.05 greater than the baseline.
IsImprovementBase: Marked as not an improvement because the compare was not 5% less than the baseline, or the value was too small.
IsRegressionBase: Marked as regression because the compare was 5% greater than the baseline, and the value was not too small.
IsRegressionChecked: Marked as regression because the three check build points were 0.05 greater than the baseline.
IsRegressionWindowed: Marked as regression because 162.0041171183368 > 140.82233369196862.
IsChangePoint: Marked as a change because one of 6/8/2022 9:45:10 AM, 6/23/2022 2:33:56 PM, 8/1/2022 4:16:36 PM, 8/5/2022 10:47:59 PM falls between 7/28/2022 9:13:34 AM and 8/5/2022 10:47:59 PM.
IsRegressionStdDev: Marked as regression because -16.15588523243305 (T) = (0 -155.80685151415716) / Math.Sqrt((18.262167754812662 / (46)) + (12.77726289932357 / (28))) is less than -1.9934635666612892 = MathNet.Numerics.Distributions.StudentT.InvCDF(0, 1, (46) + (28) - 2, .025) and -0.10593337674114203 = (140.88267412027457 - 155.80685151415716) / 140.88267412027457 is less than -0.05.
IsImprovementBase: Marked as not an improvement because the compare was not 5% less than the baseline, or the value was too small.
IsChangeEdgeDetector: Marked not as a regression because Edge Detector said so.

Docs

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

Author:	performanceautofiler[bot]
Assignees:	dakersnar
Labels:	os-windows, tenet-performance, tenet-performance-benchmarks, arch-x64, area-GC-coreclr
Milestone:	-

[mangod9]

The change seems to be within the typical range for this particular test?

[mrsharm]

I agree with @mangod9, I think this issue might be noisy with respect to #72923.

I merged the PR ~9:30 AM PST for which the next point in the trend seemed to be at a similar previous level:

Consequent regressions took place after the commit with the inflection point being on 8/3:

It seems like the moving average also indicates similar behavior:

Could this be related to some other commit?

[mangod9]

Closing this older Regions related issues, since they have been investigated.