runtime: TestNeedmDeadlock failures

[gopherbot]

#!watchflakes
post <- pkg == "runtime" && test == "TestNeedmDeadlock"

Issue created automatically to collect these failures.

Example (log):

--- FAIL: TestNeedmDeadlock (5.11s)
    testenv.go:459: [/data/golang/workdir/tmp/go-build4218498514/testprogcgo.exe NeedmDeadlock] exit status: exit status 1
    crash_cgo_test.go:714: want OK
        , got Hung for 5 seconds

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "runtime" && test == "TestNeedmDeadlock"

2022-10-20 22:16 linux-s390x-ibm go@4725c71b runtime.TestNeedmDeadlock (log)

--- FAIL: TestNeedmDeadlock (5.11s)
    testenv.go:459: [/data/golang/workdir/tmp/go-build4218498514/testprogcgo.exe NeedmDeadlock] exit status: exit status 1
    crash_cgo_test.go:714: want OK
        , got Hung for 5 seconds

— watchflakes

[mknyszek]

In triage I think we want to see more failures. For context, needm is used on the C -> Go call path to get an m for the C thread. Seems like it might be similar to #43625?

If it happens again on s390x I'll loop in the s390x folks.

[mknyszek]

This continues to be the only failure in recent memory. At the end of the cycle we should put this into the backlog if we don't see any more issues.

[cherrymui]

Seems no new failure for quite a while. Move to backlog.

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "runtime" && test == "TestNeedmDeadlock"

2023-01-09 20:25 openbsd-amd64-71 go@0bbd67e5 runtime.TestNeedmDeadlock (log)

--- FAIL: TestNeedmDeadlock (1.20s)
    exec.go:146: test timed out while running command: /tmp/workdir/tmp/go-build2241571717/testprogcgo.exe NeedmDeadlock
    crash_test.go:58: /tmp/workdir/tmp/go-build2241571717/testprogcgo.exe NeedmDeadlock: signal: quit
    crash_cgo_test.go:714: want OK
        , got 

— watchflakes