Fix SpanBench

[AndyAyersMS]

Make benchmark class public, add namespace. Tweak iteration counts
to very roughly 1 second per xunit-perf iteration.

[AndyAyersMS]

@joperezr @ahsonkhan PTAL
cc @dotnet/jit-contrib

Resolves the ongoing mystery of why this benchmark hasn't been producing perf results: when I originally wrote it I did not make the benchmark class public.

Local testing using run-xunit-perf shows reasonable results now.

[ahsonkhan]

Can you rename this from Tests to something like SpanBench (or more descriptive and unique). Makes it easier to search, especially in benchview.

[AndyAyersMS]

Sure

[ahsonkhan]

Looks good to me :)

[AndyAyersMS]

Meant to ping @jorive....

[jorive]

@AndyAyersMS Changes look good. Optionally, you could change the benchmarks inner iterations to look more like this:

[Benchmark(InnerIterationCount = 10000)]
public static void TestFillAll()
{
    foreach (BenchmarkIteration iter in Benchmark.Iterations)
    {
        using (iter.StartMeasurement())
        {
            for (int i = 0; i < Benchmark.InnerIterationCount; ++i)

As-is, the results will display on BenchView like this: Span \ SpanBench \ TestFillAllSpan
I would suggest something more like: Span \ Benchmarks \ TestFillAll (remove the repetition)
What do you think?

[AndyAyersMS]

The final Span suffix is there to distinguish the span cases from the corresponding array cases -- that is there is both a TestFillAllSpan and a TestFillAllArray.

This test can be run as a perf test two ways -- under xunit perf and also as a standalone exe. I generally haven't generally used inner iteration count for the tests I write to maintain symmetry with the exe-driven portion of the testing.

Happy to change the class name to Benchmarks if you think it is an improvement.

[ahsonkhan]

@AndyAyersMS, I think SpanBench is fine.

There is already a method:

    static double Bench(Action f)

error CS0542: 'Bench': member names cannot be the same as their enclosing type [D:\j\workspace\debug_windows---17180f1b\tests\src\JIT\Performance\CodeQuality\Span\SpanBench.csproj]

[ahsonkhan]

@AndyAyersMS, you probably don't want to name your class "Benchmark"

SpanBench.cs(203,45): error CS0117: 'Benchmark' does not contain a definition for 'Iterations' [D:\j\workspace\checked_windo---f6dc6fe4\tests\src\JIT\Performance\CodeQuality\Span\SpanBench.csproj]

It gets confused with Benchmark attribute for the performance tests.

foreach (var iteration in Benchmark.Iterations)

[AndyAyersMS]

Odd that I don't see any of these errors building locally... anyways, back to SpanBench it is.

[AndyAyersMS]

Arm emulator build failure, seems widespread since roughly midnight.

07:23:12 Copied 205 artifacts from "dotnet_coreclr » master » release_windows_nt_bld" build number 1215
07:23:12 ERROR: Unable to find project for artifact copy: dotnet_corefx/master/linuxarmemulator_softfp_cross_release
07:23:12 This may be due to incorrect project name or permission settings; see help for project name in job configuration

looks like this artifact comes from a corefx build, last good run has:

Copied 1 artifact from "dotnet_corefx » master » linuxarmemulator_softfp_cross_debug" build number 116

Root cause is likely this change which broke arm builds in CoreFX:
dotnet/corefx#16378

[AndyAyersMS]

@ahsonkhan I'll abandon this since your #9790 has incorporated these changes already.

[hqueue]

@dotnet-bot test Linux ARM Emulator Cross Release Build
@dotnet-bot test Linux ARM Emulator Cross Debug Build

[ahsonkhan]

I'll abandon this since your #9790 has incorporated these changes already.

Sounds good. Close this PR?