runtime: TestRuntimeLockMetricsAndProfile/runtime.lock failures

[gopherbot]

#!watchflakes
default <- test ~ `TestRuntimeLockMetricsAndProfile/runtime.lock/` ||
    log ~ `panic: test timed out after 5m0s(.|\n)+TestRuntimeLockMetricsAndProfile/runtime.lock/sample-\d \(4m`

Issue created automatically to collect these failures.

Example (log):

=== RUN   TestRuntimeLockMetricsAndProfile/runtime.lock/sample-1
    metrics_test.go:1065: lock contention growth in runtime/pprof's view  (1.241778s)
    metrics_test.go:1066: lock contention growth in runtime/metrics' view (1.241730s)
    metrics_test.go:1104: stack [runtime.unlock runtime_test.TestRuntimeLockMetricsAndProfile.func5.1 runtime_test.(*contentionWorker).run] has samples totaling n=199 value=1207128831
    metrics_test.go:1192: mutex profile reported contention count different from the known true count (199 != 200)
--- FAIL: TestRuntimeLockMetricsAndProfile/runtime.lock/sample-1 (1.25s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "runtime:cpu4" && test == "TestRuntimeLockMetricsAndProfile/runtime.lock/sample-1"

2024-11-27 15:22 gotip-linux-loong64 go@7e095086 runtime:cpu4.TestRuntimeLockMetricsAndProfile/runtime.lock/sample-1 (log)

=== RUN   TestRuntimeLockMetricsAndProfile/runtime.lock/sample-1
    metrics_test.go:1065: lock contention growth in runtime/pprof's view  (1.241778s)
    metrics_test.go:1066: lock contention growth in runtime/metrics' view (1.241730s)
    metrics_test.go:1104: stack [runtime.unlock runtime_test.TestRuntimeLockMetricsAndProfile.func5.1 runtime_test.(*contentionWorker).run] has samples totaling n=199 value=1207128831
    metrics_test.go:1192: mutex profile reported contention count different from the known true count (199 != 200)
--- FAIL: TestRuntimeLockMetricsAndProfile/runtime.lock/sample-1 (1.25s)

— watchflakes

[mknyszek]

CC @golang/loong64

[abner-chenc]

CC @golang/loong64

I'm trying to reproduce this error.

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "runtime:cpu4" && test == "TestRuntimeLockMetricsAndProfile/runtime.lock/sample-1"

2025-03-06 21:41 gotip-linux-ppc64le_power10 go@232dfd22 runtime:cpu4.TestRuntimeLockMetricsAndProfile/runtime.lock/sample-1 (log)

=== RUN   TestRuntimeLockMetricsAndProfile/runtime.lock/sample-1
    metrics_test.go:1065: lock contention growth in runtime/pprof's view  (0.082601s)
    metrics_test.go:1066: lock contention growth in runtime/metrics' view (0.082592s)
    metrics_test.go:1104: stack [runtime.unlock runtime_test.TestRuntimeLockMetricsAndProfile.func5.1 runtime_test.(*contentionWorker).run] has samples totaling n=199 value=80474842
    metrics_test.go:1192: mutex profile reported contention count different from the known true count (199 != 200)
--- FAIL: TestRuntimeLockMetricsAndProfile/runtime.lock/sample-1 (0.10s)

— watchflakes

[mknyszek]

Looks like (perhaps unsurprisingly) this is a more general problem.