runtime:mayMoreStackPreempt: TestReadMetricsSched failures

[gopherbot]

#!watchflakes
default <- pkg == "runtime:mayMoreStackPreempt" && test == "TestReadMetricsSched"

Issue created automatically to collect these failures.

Example (log):

=== RUN   TestReadMetricsSched
    metrics_test.go:1581: C:\b\s\w\ir\x\t\go-build1297006110\testprog.exe SchedMetrics: exit status 1
    metrics_test.go:1584: output:
        === Checking "base"
        	/sched/goroutines/not-in-go:goroutines: 0
        	/sched/goroutines/runnable:goroutines: 0
        	/sched/goroutines/running:goroutines: 1
        	/sched/goroutines/waiting:goroutines: 22
        	/sched/goroutines-created:goroutines: 22
        	/sched/threads/total:threads: 19
...
        	/sched/goroutines/running:goroutines: 2
        	/sched/goroutines/waiting:goroutines: 1021
        	/sched/goroutines-created:goroutines: 1042
        	/sched/threads/total:threads: 19
        
        
        
        wanted:
        OK
--- FAIL: TestReadMetricsSched (0.15s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "runtime:mayMoreStackPreempt" && test == "TestReadMetricsSched"

2025-09-29 21:06 gotip-windows-amd64-longtest go@fc88e18b runtime:mayMoreStackPreempt.TestReadMetricsSched (log)

=== RUN   TestReadMetricsSched
    metrics_test.go:1581: C:\b\s\w\ir\x\t\go-build1297006110\testprog.exe SchedMetrics: exit status 1
    metrics_test.go:1584: output:
        === Checking "base"
        	/sched/goroutines/not-in-go:goroutines: 0
        	/sched/goroutines/runnable:goroutines: 0
        	/sched/goroutines/running:goroutines: 1
        	/sched/goroutines/waiting:goroutines: 22
        	/sched/goroutines-created:goroutines: 22
        	/sched/threads/total:threads: 19
...
        	/sched/goroutines/running:goroutines: 2
        	/sched/goroutines/waiting:goroutines: 1021
        	/sched/goroutines-created:goroutines: 1042
        	/sched/threads/total:threads: 19
        
        
        
        wanted:
        OK
--- FAIL: TestReadMetricsSched (0.15s)

— watchflakes

[qmuntal]

@mknyszek your good friend TestReadMetricsSched strikes again 😄.

[mknyszek]

Ugh. Okay. I think I need to loosen the threads check. Even in a subprocess it looks like it's possible to just create an arbitrary number of threads.

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "runtime:mayMoreStackPreempt" && test == "TestReadMetricsSched"

2025-10-02 19:52 gotip-windows-amd64-longtest go@bbdff9e8 runtime:mayMoreStackPreempt.TestReadMetricsSched (log)

=== RUN   TestReadMetricsSched
    metrics_test.go:1581: C:\b\s\w\ir\x\t\go-build1154506909\testprog.exe SchedMetrics: exit status 1
    metrics_test.go:1584: output:
        === Checking "base"
        	/sched/goroutines/not-in-go:goroutines: 0
        	/sched/goroutines/runnable:goroutines: 0
        	/sched/goroutines/running:goroutines: 1
        	/sched/goroutines/waiting:goroutines: 22
        	/sched/goroutines-created:goroutines: 22
        	/sched/threads/total:threads: 7
...
        	/sched/goroutines/running:goroutines: 1
        	/sched/goroutines/waiting:goroutines: 1022
        	/sched/goroutines-created:goroutines: 1042
        	/sched/threads/total:threads: 19
        
        
        
        wanted:
        OK
--- FAIL: TestReadMetricsSched (0.14s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "runtime:mayMoreStackPreempt" && test == "TestReadMetricsSched"

2025-10-03 11:04 gotip-darwin-arm64-longtest go@d5b95039 runtime:mayMoreStackPreempt.TestReadMetricsSched (log)

=== RUN   TestReadMetricsSched
    metrics_test.go:1581: /Users/swarming/.swarming/w/ir/x/t/go-build3741385003/testprog.exe SchedMetrics: exit status 1
    metrics_test.go:1584: output:
        === Checking "base"
        	/sched/goroutines/not-in-go:goroutines: 0
        	/sched/goroutines/runnable:goroutines: 0
        	/sched/goroutines/running:goroutines: 1
        	/sched/goroutines/waiting:goroutines: 9
        	/sched/goroutines-created:goroutines: 10
        	/sched/threads/total:threads: 7
...
        	/sched/goroutines/running:goroutines: 2
        	/sched/goroutines/waiting:goroutines: 1008
        	/sched/goroutines-created:goroutines: 1030
        	/sched/threads/total:threads: 19
        
        
        
        wanted:
        OK
--- FAIL: TestReadMetricsSched (0.10s)

— watchflakes

[gopherbot]

Change https://go.dev/cl/708868 mentions this issue: runtime: bump thread count slack for TestReadMetricsSched

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "runtime:mayMoreStackPreempt" && test == "TestReadMetricsSched"

2025-10-03 19:30 gotip-linux-amd64-longtest go@1caa95ac runtime:mayMoreStackPreempt.TestReadMetricsSched (log)

=== RUN   TestReadMetricsSched
    metrics_test.go:1581: /home/swarming/.swarming/w/ir/x/t/go-build3475175509/testprog.exe SchedMetrics: exit status 1
    metrics_test.go:1584: output:
        === Checking "base"
        	/sched/goroutines/not-in-go:goroutines: 0
        	/sched/goroutines/runnable:goroutines: 0
        	/sched/goroutines/running:goroutines: 1
        	/sched/goroutines/waiting:goroutines: 21
        	/sched/goroutines-created:goroutines: 22
        	/sched/threads/total:threads: 8
...
        	/sched/goroutines/running:goroutines: 3
        	/sched/goroutines/waiting:goroutines: 1019
        	/sched/goroutines-created:goroutines: 1042
        	/sched/threads/total:threads: 19
        
        
        
        wanted:
        OK
--- FAIL: TestReadMetricsSched (0.10s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "runtime:mayMoreStackPreempt" && test == "TestReadMetricsSched"

2025-10-03 20:51 gotip-linux-amd64-longtest go@2a71af11 runtime:mayMoreStackPreempt.TestReadMetricsSched (log)

=== RUN   TestReadMetricsSched
    metrics_test.go:1581: /home/swarming/.swarming/w/ir/x/t/go-build1593553561/testprog.exe SchedMetrics: exit status 1
    metrics_test.go:1584: output:
        === Checking "base"
        	/sched/goroutines/not-in-go:goroutines: 0
        	/sched/goroutines/runnable:goroutines: 0
        	/sched/goroutines/running:goroutines: 1
        	/sched/goroutines/waiting:goroutines: 21
        	/sched/goroutines-created:goroutines: 22
        	/sched/threads/total:threads: 8
...
        	/sched/goroutines/running:goroutines: 2
        	/sched/goroutines/waiting:goroutines: 1020
        	/sched/goroutines-created:goroutines: 1042
        	/sched/threads/total:threads: 19
        
        
        
        wanted:
        OK
--- FAIL: TestReadMetricsSched (0.11s)

— watchflakes