runtime/pprof: TestCPUProfileMultithreadMagnitude failures

[gopherbot]

#!watchflakes
post <- pkg == "runtime/pprof" && test == "TestCPUProfileMultithreadMagnitude"

Issue created automatically to collect these failures.

Example (log):

--- FAIL: TestCPUProfileMultithreadMagnitude (1.02s)
    pprof_test.go:123: Running on Linux 4.18.0
    --- FAIL: TestCPUProfileMultithreadMagnitude/serial (0.54s)
        pprof_test.go:189: Running with 1 workers
        pprof_test.go:524: total 19 CPU profile samples collected:
            7: 0x1758ec (runtime/pprof.cpuHog0:61 runtime/pprof.cpuHog1:55) 0x175839 (runtime/pprof.cpuHogger:41) 0x176b1b (runtime/pprof.TestCPUProfileMultithreadMagnitude.func3.1.1.1:202) labels: map[]

            6: 0x85b40 (runtime.asyncPreempt:7) 0x1758eb (runtime/pprof.cpuHog0:60 runtime/pprof.cpuHog1:55) 0x175839 (runtime/pprof.cpuHogger:41) 0x176b1b (runtime/pprof.TestCPUProfileMultithreadMagnitude.func3.1.1.1:202) labels: map[]

            3: 0x85b40 (runtime.asyncPreempt:7) 0x1758f9 (runtime/pprof.cpuHog0:62 runtime/pprof.cpuHog1:55) 0x175839 (runtime/pprof.cpuHogger:41) 0x176b1b (runtime/pprof.TestCPUProfileMultithreadMagnitude.func3.1.1.1:202) labels: map[]

            3: 0x1758fa (runtime/pprof.cpuHog0:64 runtime/pprof.cpuHog1:55) 0x175839 (runtime/pprof.cpuHogger:41) 0x176b1b (runtime/pprof.TestCPUProfileMultithreadMagnitude.func3.1.1.1:202) labels: map[]

        pprof_test.go:595: runtime/pprof.cpuHog1: 19
        pprof_test.go:226: compare 90.268ms vs 190ms
        pprof_test.go:228: compare got CPU usage reports are too different (limit -40.0%, got -52.5%) want nil
    pprof_test.go:126: Failure of this test may indicate that your system suffers from a known Linux kernel bug fixed on newer kernels. See https://golang.org/issue/49065.

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "runtime/pprof" && test == "TestCPUProfileMultithreadMagnitude"

2022-09-21 20:24 linux-s390x-ibm go@e0a364b0 runtime/pprof.TestCPUProfileMultithreadMagnitude (log)

--- FAIL: TestCPUProfileMultithreadMagnitude (1.02s)
    pprof_test.go:123: Running on Linux 4.18.0
    --- FAIL: TestCPUProfileMultithreadMagnitude/serial (0.54s)
        pprof_test.go:189: Running with 1 workers
        pprof_test.go:524: total 19 CPU profile samples collected:
            7: 0x1758ec (runtime/pprof.cpuHog0:61 runtime/pprof.cpuHog1:55) 0x175839 (runtime/pprof.cpuHogger:41) 0x176b1b (runtime/pprof.TestCPUProfileMultithreadMagnitude.func3.1.1.1:202) labels: map[]

            6: 0x85b40 (runtime.asyncPreempt:7) 0x1758eb (runtime/pprof.cpuHog0:60 runtime/pprof.cpuHog1:55) 0x175839 (runtime/pprof.cpuHogger:41) 0x176b1b (runtime/pprof.TestCPUProfileMultithreadMagnitude.func3.1.1.1:202) labels: map[]

            3: 0x85b40 (runtime.asyncPreempt:7) 0x1758f9 (runtime/pprof.cpuHog0:62 runtime/pprof.cpuHog1:55) 0x175839 (runtime/pprof.cpuHogger:41) 0x176b1b (runtime/pprof.TestCPUProfileMultithreadMagnitude.func3.1.1.1:202) labels: map[]

            3: 0x1758fa (runtime/pprof.cpuHog0:64 runtime/pprof.cpuHog1:55) 0x175839 (runtime/pprof.cpuHogger:41) 0x176b1b (runtime/pprof.TestCPUProfileMultithreadMagnitude.func3.1.1.1:202) labels: map[]

        pprof_test.go:595: runtime/pprof.cpuHog1: 19
        pprof_test.go:226: compare 90.268ms vs 190ms
        pprof_test.go:228: compare got CPU usage reports are too different (limit -40.0%, got -52.5%) want nil
    pprof_test.go:126: Failure of this test may indicate that your system suffers from a known Linux kernel bug fixed on newer kernels. See https://golang.org/issue/49065.

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "runtime/pprof" && test == "TestCPUProfileMultithreadMagnitude"

2023-12-01 21:36 linux-ppc64-sid-buildlet go@cf3d253c runtime/pprof.TestCPUProfileMultithreadMagnitude (log)

--- FAIL: TestCPUProfileMultithreadMagnitude (213.48s)
    pprof_test.go:120: Running on Linux 6.5
    --- FAIL: TestCPUProfileMultithreadMagnitude/parallel (210.21s)
        pprof_test.go:186: Running with 4 workers
        pprof_test.go:557: total 171 CPU profile samples collected:
            48: 0x17a290 (runtime/pprof.cpuHog0:64 runtime/pprof.cpuHog1:55) 0x17a1f7 (runtime/pprof.cpuHogger:41) 0x17b893 (runtime/pprof.TestCPUProfileMultithreadMagnitude.func3.2.1.1:232) labels: map[]

            50: 0x17a268 (runtime/pprof.cpuHog0:60 runtime/pprof.cpuHog1:55) 0x17a1f7 (runtime/pprof.cpuHogger:41) 0x17b893 (runtime/pprof.TestCPUProfileMultithreadMagnitude.func3.2.1.1:232) labels: map[]

            28: 0x17a274 (runtime/pprof.cpuHog0:60 runtime/pprof.cpuHog1:55) 0x17a1f7 (runtime/pprof.cpuHogger:41) 0x17b893 (runtime/pprof.TestCPUProfileMultithreadMagnitude.func3.2.1.1:232) labels: map[]
...
            1: 0x9fcbc (time.subMono:921 time.Since:932) 0x17a227 (runtime/pprof.cpuHogger:40) 0x17b893 (runtime/pprof.TestCPUProfileMultithreadMagnitude.func3.2.1.1:232) labels: map[]

            1: 0x58930 (runtime/internal/atomic.(*Int64).Load:74 runtime.checkTimers:3964) 0x55dbb (runtime.findRunnable:3176) 0x58683 (runtime.schedule:3884) 0x5902b (runtime.goschedImpl:4081) 0x5924f (runtime.gopreempt_m:4098) 0x87833 (runtime.mcall:198) labels: map[]

            1: 0x8b4d0 (runtime.futex:644) 0x4928b (runtime.futexwakeup:82) 0x1b56b (runtime.notewakeup:155) 0x54e33 (runtime.startm:2911) 0x556c7 (runtime.wakep:3022) 0x51447 (runtime.ready:986) 0x64e0f (runtime.readyWithTime.goready.func1:413) 0x878d7 (runtime.systemstack:255) 0x64dcb (runtime.goready:412 runtime.readyWithTime:99) 0x653cf (runtime.semrelease1:231) 0x8646b (sync.runtime_Semrelease:72) 0x92627 (sync.(*WaitGroup).Add:81) 0x17b97f (sync.(*WaitGroup).Done:87) 0x17b8eb (runtime/pprof.TestCPUProfileMultithreadMagnitude.func3.2.1.1:234) labels: map[]

        pprof_test.go:628: found 20701 samples in expected function runtime/pprof.cpuHog1
        pprof_test.go:214: compare 6m18.207928s user + 28.398215s system = 6m46.606143s vs 3m27.66s
        pprof_test.go:216: compare got CPU usage reports are too different (limit -40.0%, got -48.9%) want nil
    pprof_test.go:123: Failure of this test may indicate that your system suffers from a known Linux kernel bug fixed on newer kernels. See https://golang.org/issue/49065.

— watchflakes