Re: [PATCH 2/2] tests/qtest: make more migration pre-copy scenarios run non-live

[Daniel P . Berrangé]

On Tue, Apr 18, 2023 at 04:52:32PM -0300, Fabiano Rosas wrote:
> Daniel P. Berrangé <berrange@redhat.com> writes:
> 
> > There are 27 pre-copy live migration scenarios being tested. In all of
> > these we force non-convergance and run for one iteration, then let it
> > converge and wait for completion during the second (or following)
> > iterations. At 3 mbps bandwidth limit the first iteration takes a very
> > long time (~30 seconds).
> >
> > While it is important to test the migration passes and convergance
> > logic, it is overkill to do this for all 27 pre-copy scenarios. The
> > TLS migration scenarios in particular are merely exercising different
> > code paths during connection establishment.
> >
> > To optimize time taken, switch most of the test scenarios to run
> > non-live (ie guest CPUs paused) with no bandwidth limits. This gives
> > a massive speed up for most of the test scenarios.
> >
> > For test coverage the following scenarios are unchanged
> >
> >  * Precopy with UNIX sockets
> >  * Precopy with UNIX sockets and dirty ring tracking
> >  * Precopy with XBZRLE
> >  * Precopy with multifd
> >
> > Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> 
> ...
> 
> > -        qtest_qmp_eventwait(to, "RESUME");
> > +        if (!args->live) {
> > +            qtest_qmp_discard_response(to, "{ 'execute' : 'cont'}");
> > +        }
> > +        if (!got_resume) {
> > +            qtest_qmp_eventwait(to, "RESUME");
> > +        }
> 
> Hi Daniel,
> 
> On an aarch64 host I'm sometimes (~30%) seeing a hang here on a TLS test:
> 
> ../configure --target-list=aarch64-softmmu --enable-gnutls
> 
> ... ./tests/qtest/migration-test --tap -k -p 
> /aarch64/migration/precopy/tcp/tls/psk/match

I never came to a satisfactory understanding of why this problem hits
you. I've just sent out a new version of this series, which has quite
a few differences, so possibly I've fixed it by luck.

So if you have time, I'd appreciate any testing you can try on

  https://lists.gnu.org/archive/html/qemu-devel/2023-04/msg03688.html


With regards,
Daniel
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