[pgo] Assertion failed '((-slop) <= diff) && (diff <= slop)' during 'Compute edge weights (2, false)'

[jakobbotsch]

Pipeline: runtime-coreclr pgo
Config: win-arm64 Checked fullpgo_random_gdv_methodprofiling_only
Link: https://dev.azure.com/dnceng-public/public/_build/results?buildId=62149&view=ms.vss-test-web.build-test-results-tab&runId=1274480&resultId=108923&paneView=debug

Assert failure(PID 11476 [0x00002cd4], Thread: 7904 [0x1ee0]): Assertion failed '((-slop) <= diff) && (diff <= slop)' in 'System.RuntimeType:GetConstructorCandidates(System.String,int,int,System.Type[],bool):ListBuilder`1[System.Reflection.ConstructorInfo]:this' during 'Compute edge weights (2, false)' (IL size 103; hash 0xfc7100fa; Tier1)

File: D:\a\_work\1\s\src\coreclr\jit\fgprofile.cpp Line: 3941
Image: D:\h\w\BE4A09E7\p\corerun.exe

cc @AndyAyersMS

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Issue Details

---

Pipeline: runtime-coreclr pgo
Config: win-arm64 Checked fullpgo_random_gdv_methodprofiling_only
Link: https://dev.azure.com/dnceng-public/public/_build/results?buildId=62149&view=ms.vss-test-web.build-test-results-tab&runId=1274480&resultId=108923&paneView=debug

Assert failure(PID 11476 [0x00002cd4], Thread: 7904 [0x1ee0]): Assertion failed '((-slop) <= diff) && (diff <= slop)' in 'System.RuntimeType:GetConstructorCandidates(System.String,int,int,System.Type[],bool):ListBuilder`1[System.Reflection.ConstructorInfo]:this' during 'Compute edge weights (2, false)' (IL size 103; hash 0xfc7100fa; Tier1)

File: D:\a\_work\1\s\src\coreclr\jit\fgprofile.cpp Line: 3941
Image: D:\h\w\BE4A09E7\p\corerun.exe

cc @AndyAyersMS

Author:	jakobbotsch
Assignees:	-
Labels:	area-CodeGen-coreclr, untriaged
Milestone:	-

[AndyAyersMS]

I just loosened the threshold recently: #76409. Looks like we'll have to loosen even more.

[AndyAyersMS]

I'm not able to repro this so far. Probably timing dependen (or maybe harder to repro with the new pgo strategy?).

Will keep trying.

It's no longer happening in the CI runs. So, removing the blocking label.

[AndyAyersMS]

I still can't repro, either with locally built bits or runfo downloaded bits, so am going to close this.

Would not be surprising if further tweaks are needed to this assert, but don't want to modify it blindly. So a fix will have to wait for a more consistent repro.

[jakobbotsch]

It's no longer happening in the CI runs. So, removing the blocking label.

Looks like it happened again on Saturday's run:
https://dev.azure.com/dnceng-public/public/_build/results?buildId=67103&view=ms.vss-test-web.build-test-results-tab&runId=1365674&resultId=192095&paneView=dotnet-dnceng.dnceng-anon-build-release-tasks.helix-anon-test-information-tab
https://helixre107v0xdeko0k025g8.blob.core.windows.net/dotnet-runtime-refs-heads-main-7abbdb10ea47480a83/System.Collections.Concurrent.Tests/1/console.6aec2436.log?helixlogtype=result