[Perf] ubuntu 18.04/x64 : Regression on 9/1/2022 12:26:41 AM

[performanceautofiler]

Run Information

Architecture	x64
OS	ubuntu 18.04
Baseline	51191575ccced7759ab2b82c7348a488f56d6f52
Compare	d684343d7fc6e050d5c7fa11298dc1b6a5ee7a0e
Diff	Diff

Regressions in System.Text.Tests.Perf_StringBuilder

Benchmark	Baseline	Test	Test/Base	Test Quality	Edge Detector	Baseline IR	Compare IR	IR Ratio	Baseline ETL	Compare ETL
Append_Char - Duration of single invocation	175.02 ns	264.12 ns	1.51	0.03	False
Append_Char - Duration of single invocation	104.97 μs	183.04 μs	1.74	0.01	False

Test Report

Repro

git clone https://github.com/dotnet/performance.git
python3 .\performance\scripts\benchmarks_ci.py -f net6.0 --filter 'System.Text.Tests.Perf_StringBuilder*'

Payloads

Baseline
Compare

Histogram

System.Text.Tests.Perf_StringBuilder.Append_Char(length: 100)

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 264.12188105837026 > 188.82267289594824.
IsChangePoint: Marked as a change because one of 7/6/2022 7:05:00 PM, 8/17/2022 6:09:21 PM, 8/31/2022 7:50:47 PM, 9/1/2022 1:45:20 PM falls between 8/23/2022 11:46:46 PM and 9/1/2022 1:45:20 PM.
IsRegressionStdDev: Marked as regression because -44.44740000736066 (T) = (0 -265.78910636943624) / Math.Sqrt((18.283398912627536 / (59)) + (11.253570506614611 / (3))) is less than -2.0002978220134566 = MathNet.Numerics.Distributions.StudentT.InvCDF(0, 1, (59) + (3) - 2, .025) and -0.5082955632704216 = (176.21818484510322 - 265.78910636943624) / 176.21818484510322 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.Text.Tests.Perf_StringBuilder.Append_Char(length: 100000)

```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 183.03954739410295 > 110.03620019158978.
IsChangePoint: Marked as a change because one of 7/6/2022 7:05:00 PM, 8/31/2022 7:50:47 PM, 9/1/2022 1:45:20 PM falls between 8/23/2022 11:46:46 PM and 9/1/2022 1:45:20 PM.
IsRegressionStdDev: Marked as regression because -337.91006197493664 (T) = (0 -182860.72062063418) / Math.Sqrt((419037.07607286004 / (59)) + (137441.58204282986 / (3))) is less than -2.0002978220134566 = MathNet.Numerics.Distributions.StudentT.InvCDF(0, 1, (59) + (3) - 2, .025) and -0.7393851209042447 = (105129.51871496484 - 182860.72062063418) / 105129.51871496484 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