Re: [PATCH v6 06/10] acpi/tests/avocado/bits: disable smilatency test since it does not pass everytime

[Ani Sinha]

On Thu, Oct 20, 2022 at 11:17 PM Alex Bennée <alex.bennee@linaro.org> wrote:
>
>
> Ani Sinha <ani@anisinha.ca> writes:
>
> > smilatency test is latency sensitive and does not pass deterministically 
> > when
> > run in QEMU environment under biosbits. Disable the test suite for now.
> >
> > Example failure:
> >
> > ==== SMI latency test ====
> > Warning: touching the keyboard can affect the results of this test.
> > Starting test. Wait here, I will be back in 15 seconds.
> > [assert] SMI latency < 150us to minimize risk of OS timeouts FAIL
> >   1us   < t <=  10us; average = 1372ns; count = 10912449
> >    Times between first few observations:  176us 1646ns 1441ns 1450ns 1462ns
> >   10us  < t <= 100us; average = 16us; count = 1187
> >    Times between first few observations:   15ms 3148us 5856us   49ms   33ms
> >   100us < t <=   1ms; average = 259us; count = 8
> >    Times between first few observations:  111ms 2227ms 1779ms  999ms  219ms
> >   0 SMI detected using MSR_SMI_COUNT (MSR 0x34)
> >   Summary of impact: observed maximum latency = 298us
> > Summary: 0 passed, 1 failed
>
> Is this because of TCG slowness? You might try running under icount for
> a more consistent elapsed time for the guest.

bang on! It does indeed pass consistently with "-icount auto" set. I
have tried 10 iterations on baremetal and on a VM environment.
I will remove smilatency test stuff from the patchset for now and add
that additional command line in v7.

>
> >
> > Cc: Daniel P. Berrangé <berrange@redhat.com>
> > Cc: Paolo Bonzini <pbonzini@redhat.com>
> > Cc: Maydell Peter <peter.maydell@linaro.org>
> > Cc: John Snow <jsnow@redhat.com>
> > Cc: Thomas Huth <thuth@redhat.com>
> > Cc: Alex Bennée <alex.bennee@linaro.org>
> > Cc: Igor Mammedov <imammedo@redhat.com>
> > Cc: Michael Tsirkin <mst@redhat.com>
> > Signed-off-by: Ani Sinha <ani@anisinha.ca>
> > ---
> >  tests/avocado/acpi-bits/bits-tests/smilatency.py2 | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/tests/avocado/acpi-bits/bits-tests/smilatency.py2 
> > b/tests/avocado/acpi-bits/bits-tests/smilatency.py2
> > index d616970b31..e907c55cc2 100644
> > --- a/tests/avocado/acpi-bits/bits-tests/smilatency.py2
> > +++ b/tests/avocado/acpi-bits/bits-tests/smilatency.py2
> > @@ -37,8 +37,9 @@ import time
> >  import usb
> >
> >  def register_tests():
> > -    testsuite.add_test("SMI latency test", smi_latency);
> > -    testsuite.add_test("SMI latency test with USB disabled via BIOS 
> > handoff", test_with_usb_disabled, runall=False);
> > +    pass
> > +    # testsuite.add_test("SMI latency test", smi_latency);
> > +    # testsuite.add_test("SMI latency test with USB disabled via BIOS 
> > handoff", test_with_usb_disabled, runall=False);
> >
> >  def smi_latency():
> >      MSR_SMI_COUNT = 0x34
>
>
> --
> Alex Bennée