[Perf] Windows/arm64: 1 Regression on 1/27/2023 12:48:15 AM

[performanceautofiler]

Run Information

Architecture	arm64
OS	Windows 10.0.19041
Baseline	a2c4d79f88965a1fecba02331378cd335f55df9c
Compare	007df054a526ed9e3dc70b43bfa330943bd4816a
Diff	Diff

Regressions in System.IO.Tests.Perf_RandomAccess_NoBuffering

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector	Baseline IR	Compare IR	IR Ratio	Baseline ETL	Compare ETL
WriteGatherAsync - Duration of single invocation	8.22 ms	10.05 ms	1.22	0.38	False

Test Report

Repro

git clone https://github.com/dotnet/performance.git
py .\performance\scripts\benchmarks_ci.py -f net8.0 --filter 'System.IO.Tests.Perf_RandomAccess_NoBuffering*'

Payloads

Baseline
Compare

Histogram

System.IO.Tests.Perf_RandomAccess_NoBuffering.WriteGatherAsync(fileSize: 1048576, count: 4)

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 10.052692321428573 > 8.78240883097166.
IsChangePoint: Marked as a change because one of 11/29/2022 4:49:06 AM, 1/26/2023 7:41:12 PM, 2/2/2023 2:17:49 AM falls between 1/24/2023 11:54:43 AM and 2/2/2023 2:17:49 AM.
IsRegressionStdDev: Marked as regression because -6.850344067282024 (T) = (0 -9559051.95478597) / Math.Sqrt((135695864450.74908 / (19)) + (312008424545.22473 / (20))) is less than -2.026192463026769 = MathNet.Numerics.Distributions.StudentT.InvCDF(0, 1, (19) + (20) - 2, .025) and -0.12116724728151568 = (8525982.165429572 - 9559051.95478597) / 8525982.165429572 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

[DrewScoggins]

This looks like it turned out to be something.