System.Tests.GCExtendedTests.GetAllocatedBytesForCurrentThread - Allocated too much

[danmoseley]

Runfo in last 30 days as of 10/3

• 5 occurrences - 1x Rolling run + 4x PR
• As of 8/4 there was 1x Rolling run + 1x PR (it was too rare to file it back then)

Original Report

❌ System.Tests.GCExtendedTests.GetAllocatedBytesForCurrentThread(size: 1000)

Allocated too much: start: 84649544 end: 84749920 size: 1000
Expected: True
Actual:   False
Stack Trace
   at System.Tests.GCExtendedTests.GetAllocatedBytesForCurrentThread(Int32 size) in /_/src/libraries/System.Runtime/tests/System/GCTests.cs:line 798
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
   at System.Reflection.MethodInvoker.Invoke(Object obj, IntPtr* args, BindingFlags invokeAttr) in /_/src/libraries/System.Private.CoreLib/src/System/Reflection/MethodInvoker.cs:line 64

Debian.10.Amd64.Open

Console log: 'System.Runtime.Tests' from job 8b265039-da4a-4577-9fe9-3ae7a32573d4 (ubuntu.1804.amd64.open.rt) using docker image mcr.microsoft.com/dotnet-buildtools/prereqs:debian-10-helix-amd64-20220810215022-f344011 on a002IZM

https://dev.azure.com/dnceng/public/_build/results?buildId=1959322&view=ms.vss-test-web.build-test-results-tab&runId=50341050&paneView=dotnet-dnceng.dnceng-build-release-tasks.helix-test-information-tab&resultId=185272

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Issue Details

---

❌ System.Tests.GCExtendedTests.GetAllocatedBytesForCurrentThread [[Console]](https://helixre107v0xdeko0k025g8.blob.core.windows.net/dotnet-runtime-refs-pull-74338-merge-8b265039da4a45779f/System.Runtime.Tests/1/console.5c513ad0.log?helixlogtype=result) [[Details]](https://dev.azure.com/dnceng//public/_build/results?buildId=1959322&view=ms.vss-test-web.build-test-results-tab&runId=50341050&resultId=185272&paneView=debug) [[Artifacts]](https://dev.azure.com/dnceng//public/_build/results?buildId=1959322&view=ms.vss-test-web.build-test-results-tab&runId=50341050&resultId=185272&paneView=dotnet-dnceng.dnceng-build-release-tasks.helix-test-information-tab) [[0.01% failure rate]](https://dev.azure.com/dnceng//public/_build/results?buildId=1959322&view=ms.vss-test- ❌ System.Tests.GCExtendedTests.GetAllocatedBytesForCurrentThread(size: 1000) ``` Allocated too much: start: 84649544 end: 84749920 size: 1000 Expected: True Actual: False Stack Trace at System.Tests.GCExtendedTests.GetAllocatedBytesForCurrentThread(Int32 size) in /_/src/libraries/System.Runtime/tests/System/GCTests.cs:line 798 at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor) at System.Reflection.MethodInvoker.Invoke(Object obj, IntPtr* args, BindingFlags invokeAttr) in /_/src/libraries/System.Private.CoreLib/src/System/Reflection/MethodInvoker.cs:line 64 ``` Debian.10.Amd64.Open

Author:	danmoseley
Assignees:	-
Labels:	`area-GC-coreclr`, `untriaged`
Milestone:	-

[mangod9]

this seems to be a new failure, would be good to determine if some recent change might have affected this.

[danmoseley]

There is some slop already in the text, so apparently it's not expected to be totally deterministic?

        Assert.True((end - start) < 5 * size, $"Allocated too much: start: {start} end: {end} size: {size}");

So it would allocate 1K, allow up to 5K but it was 10K

[karelz]

Happens on all platforms. Roughly 1x per week - see top post updated