JIT/Methodical/tailcall_v4/hijacking/hijacking test hang

[jkotas]

Build Information

Build: https://dev.azure.com/dnceng-public/cbb18261-c48f-4abb-8651-8cdcb5474649/_build/results?buildId=1132805
Build error leg or test failing: JIT/Methodical/tailcall_v4/hijacking/hijacking.cmd
Pull request: #118944

Error Message

Fill the error message using step by step known issues guidance.

{
  "ErrorMessage": "tailcall_v4/hijacking/hijacking.cmd Timed Out",
  "ErrorPattern": "",
  "BuildRetry": false,
  "ExcludeConsoleLog": false
}

Known issue validation

Build: 🔎 https://dev.azure.com/dnceng-public/public/_build/results?buildId=1132805
Error message validated: [tailcall_v4/hijacking/hijacking.cmd Timed Out]
Result validation: ✅ Known issue matched with the provided build.
Validation performed at: 8/27/2025 6:28:31 PM UTC

Report

Build	Definition	Test	Pull Request
1132805	dotnet/runtime	JIT/Methodical/tailcall_v4/hijacking/hijacking.cmd	#118944

Summary

24-Hour Hit Count	7-Day Hit Count	1-Month Count
1	1	1

[jkotas]

The fix implemented by #118166 did not address the problem.

[MihuBot]

I'm a bot. Here is a possible related and/or duplicate issue (I may be wrong):

• tailcall_v4/hijacking/hijacking.cmd Timed Out #106134

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[jkotas]

Looked at the dump. Same symptoms as in #106134. TS_GCSuspendRedirected is set, but there is no active suspend redirect in progress.

I think the problem is that we may miss clearing of TS_GCSuspendRedirected. TS_GCSuspendRedirected is normally cleared in the slow path of switching to cooperative mode (RareDisablePreemptiveGC). The problem is that we may not even get to that slow path if the thread gets rescheduled right after we switch to preemptive mode and gets scheduled back only after the GC completes and resumes execution.