[Perf] Changes at 7/6/2022 10:15:52 AM

[performanceautofiler]

Run Information

Architecture	x64
OS	ubuntu 18.04
Baseline	206dccb7945aaa3f26599fbe742de9022ca7ef91
Compare	465fbeda31f8c55ea91f8d8c3d851a42876fa3ad
Diff	Diff

Regressions in System.Buffers.Tests.ReadOnlySequenceTests<Byte>

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector	Baseline IR	Compare IR	IR Ratio	Baseline ETL	Compare ETL
IterateGetPositionArray - Duration of single invocation	18.92 ns	23.56 ns	1.25	0.01	False
IterateGetPositionMemory - Duration of single invocation	29.55 ns	33.86 ns	1.15	0.16	False

Test Report

Repro

git clone https://github.com/dotnet/performance.git
python3 .\performance\scripts\benchmarks_ci.py -f net6.0 --filter 'System.Buffers.Tests.ReadOnlySequenceTests<Byte>*'

Payloads

Baseline
Compare

Histogram

System.Buffers.Tests.ReadOnlySequenceTests<Byte>.IterateGetPositionArray

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 23.55932642377738 > 19.79859677499863.
IsChangePoint: Marked as a change because one of 7/6/2022 8:41:56 AM, 7/12/2022 6:44:07 AM falls between 7/3/2022 4:26:07 AM and 7/12/2022 6:44:07 AM.
IsRegressionStdDev: Marked as regression because -47.55014732415081 (T) = (0 -23.081614781687644) / Math.Sqrt((0.04596877580226363 / (35)) + (0.30155332244980226 / (41))) is less than -1.9925434951804422 = MathNet.Numerics.Distributions.StudentT.InvCDF(0, 1, (35) + (41) - 2, .025) and -0.23732112086381754 = (18.65450641105484 - 23.081614781687644) / 18.65450641105484 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.

```#### System.Buffers.Tests.ReadOnlySequenceTests<Byte>.IterateGetPositionMemory

```log

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 33.85813910749477 > 31.134076114734935.
IsChangePoint: Marked as a change because one of 7/6/2022 7:05:00 PM, 7/12/2022 6:44:07 AM falls between 7/3/2022 4:26:07 AM and 7/12/2022 6:44:07 AM.
IsRegressionStdDev: Marked as regression because -23.186020515020296 (T) = (0 -33.903707233654416) / Math.Sqrt((0.7208488056645763 / (38)) + (0.22421873604889264 / (38))) is less than -1.9925434951804422 = MathNet.Numerics.Distributions.StudentT.InvCDF(0, 1, (38) + (38) - 2, .025) and -0.12088727592965619 = (30.24720501491545 - 33.903707233654416) / 30.24720501491545 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

[AndyAyersMS]

Seems like this might be from dotnet/runtime#71687

          -5 (-0.91 % of base) : 10526.dasm - System.Buffers.Tests.ReadOnlySequenceTests`1[Char][System.Char]:IterateGetPosition(System.Buffers.ReadOnlySequence`1[Char]):int:this

cc @jakobbotsch