Re: [PATCH 3/4] tests/migration: Disable autoconverge test on Travis-CI s390x

[Philippe Mathieu-Daudé]

On 3/17/20 9:26 PM, Dr. David Alan Gilbert wrote:
> * Philippe Mathieu-Daudé (address@hidden) wrote:
> > This test fails on Travis-CI s390x when configured with --disable-tcg:
> >
> >    $ make check-qtest
> >      TEST    check-qtest-s390x: tests/qtest/boot-serial-test
> >    qemu-system-s390x: -accel tcg: invalid accelerator tcg
> >    qemu-system-s390x: falling back to KVM
> >      TEST    check-qtest-s390x: tests/qtest/pxe-test
> >      TEST    check-qtest-s390x: tests/qtest/test-netfilter
> >      TEST    check-qtest-s390x: tests/qtest/test-filter-mirror
> >      TEST    check-qtest-s390x: tests/qtest/test-filter-redirector
> >      TEST    check-qtest-s390x: tests/qtest/drive_del-test
> >      TEST    check-qtest-s390x: tests/qtest/device-plug-test
> >      TEST    check-qtest-s390x: tests/qtest/virtio-ccw-test
> >      TEST    check-qtest-s390x: tests/qtest/cpu-plug-test
> >      TEST    check-qtest-s390x: tests/qtest/migration-test
> >    **
> >    ERROR:tests/qtest/migration-test.c:1229:test_migrate_auto_converge: 
> > 'got_stop' should be FALSE
> >    ERROR - Bail out! 
> > ERROR:tests/qtest/migration-test.c:1229:test_migrate_auto_converge: 'got_stop' 
> > should be FALSE
> >    make: *** [tests/Makefile.include:633: check-qtest-s390x] Error 1
>
> Before we take the hammer to it, could you try reducing it's initial
> bandwidth, the code that says:
>
>      /*
>       * Set the initial parameters so that the migration could not converge
>       * without throttling.
>       */
>      migrate_set_parameter_int(from, "downtime-limit", 1);
>      migrate_set_parameter_int(from, "max-bandwidth", 100000000); /* ~100Mb/s */
>
> knock a couple of 0's off that and see if it's happy.

You are right! One 0 is not enough, but a couple makes the test succeed.

Can that change have other (bad) effects on other archs?
IOW can I send a generic patch updating this value, or should I add a 
check on the architecture?

Thanks!

> Dave
>
> > Per David Gilbert, it might be a threshold requiring tuning:
> > "it could just be the writing is slow on s390 and the migration
> > thread fast; in which case the autocomplete wouldn't be needed.
> > Perhaps we just need to reduce the bandwidth limit."
> >
> > Disable the autoconverge test for now.
> >
> > Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
> > ---
> >   tests/qtest/migration-test.c | 10 ++++++++++
> >   1 file changed, 10 insertions(+)
> >
> > diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
> > index 3d6cc83b88..878399666e 100644
> > --- a/tests/qtest/migration-test.c
> > +++ b/tests/qtest/migration-test.c
> > @@ -1181,6 +1181,16 @@ static void test_migrate_auto_converge(void)
> >       MigrateStart *args = migrate_start_new();
> >       QTestState *from, *to;
> >       int64_t remaining, percentage;
> > +    char *travis_arch;
> > +
> > +    /*
> > +     * This test does not work reliably on Travis s390x.
> > +     */
> > +    travis_arch = getenv("TRAVIS_CPU_ARCH");
> > +    if (travis_arch && g_str_equal(travis_arch, "s390x")) {
> > +        g_test_skip("Test does not work reliably on s390x Travis containers.");
> > +        return;
> > +    }
> >   
> >       /*
> >        * We want the test to be stable and as fast as possible.
> > --
> > 2.21.1
> --
> Dr. David Alan Gilbert / address@hidden / Manchester, UK