Re: [Qemu-devel] [PATCH v3 2/6] tests: migration test deprecated commands

[Peter Xu <peterx@redhat.com>]

On Wed, Dec 27, 2017 at 10:41:02AM +0100, Juan Quintela wrote:
> Peter Xu <peterx@redhat.com> wrote:
> > On Tue, Dec 26, 2017 at 08:51:10PM +0100, Juan Quintela wrote:
> >> Peter Xu <peterx@redhat.com> wrote:
> >> > On Fri, Dec 01, 2017 at 01:58:09PM +0100, Juan Quintela wrote:
> >> >> We now test the deprecated commands everytime that we test the new
> >> >> commands.  This makes unnecesary to add tests for deprecated commands.
> >> >> 
> >> >> Signed-off-by: Juan Quintela <quintela@redhat.com>
> >> >> ---
> >> >>  tests/migration-test.c | 32 ++++++++++++++++++++++++++++----
> >> >>  1 file changed, 28 insertions(+), 4 deletions(-)
> >> >> 
> >> >> diff --git a/tests/migration-test.c b/tests/migration-test.c
> >> >> index 799e24ebc6..51f49c74e9 100644
> >> >> --- a/tests/migration-test.c
> >> >> +++ b/tests/migration-test.c
> >> >> @@ -369,7 +369,7 @@ static void migrate_check_parameter(QTestState *who, const char *parameter,
> >> >>      QDECREF(rsp);
> >> >>  }
> >> >>  
> >> >> -static void migrate_set_downtime(QTestState *who, const double value)
> >> >> +static void deprecated_set_downtime(QTestState *who, const double value)
> >> >>  {
> >> >>      QDict *rsp;
> >> >>      gchar *cmd;
> >> >> @@ -388,7 +388,7 @@ static void migrate_set_downtime(QTestState *who, const double value)
> >> >>      g_free(expected);
> >> >>  }
> >> >>  
> >> >> -static void migrate_set_speed(QTestState *who, const char *value)
> >> >> +static void deprecated_set_speed(QTestState *who, const char *value)
> >> >>  {
> >> >>      QDict *rsp;
> >> >>      gchar *cmd;
> >> >> @@ -402,6 +402,30 @@ static void migrate_set_speed(QTestState *who, const char *value)
> >> >>      migrate_check_parameter(who, "max-bandwidth", value);
> >> >>  }
> >> >>  
> >> >> +static void migrate_set_parameter(QTestState *who, const char *parameter,
> >> >> +                                  const char *value)
> >> >> +{
> >> >> +    QDict *rsp;
> >> >> +    gchar *cmd;
> >> >> +
> >> >> +    if (strcmp(parameter, "downtime-limit") == 0) {
> >> >> +        deprecated_set_downtime(who, 0.12345);
> >> >> +    }
> >> >> +
> >> >> +    if (strcmp(parameter, "max-bandwidth") == 0) {
> >> >> +        deprecated_set_speed(who, "12345");
> >> >> +    }
> >> >
> >> > I'm fine with current approach, but I would really prefer to put them
> >> > all into a standalone test, by just calling them one by one with some
> >> > specific numbers and that's all.
> >> 
> >> That means another test (at least), and we have, also at least three
> >> deprecated comands:
> >> - migrate_set_speed
> >> - migrate_set_downtime
> >> - migrate_set_cache_size
> >> 
> >> And each test makes things slower.  So I *thought* it would we wiser to
> >> just check _always_ use the deprecated an the not deprecated one.
> >> 
> >> > (luckily we only have two deprecated commands and limited tests,
> >> >  otherwise extra commands will be M*N, say "number of deprecated
> >> >  command" * "number of test mirations")
> >> 
> >> Each test takes time, so adding tests make everything much slower.
> >> Notice that setting a new setting is fast.
> >> 
> >> This was the way that I understood Dave he wanted.
> >
> > Do you mean every test is slow, or just migration tests?
> 
> Each migration test adds around 2 seconds on my machine.  So I decided
> that it was easier that each time that we check one command, we test the
> deprecated and non-deprecated versions of the command.  Amount of time
> added to the test is negigible, and we are sure that we always test both
> functions.
> 
> If we ever remove the deprecated method, we can always remove only that
> part of th etest.
> 
> 
> > Here I mean
> > to only test setting the parameters without doing real migration tests
> > (then query to make sure the settings were taking effect).  I assume
> > that should be fast too?  Thanks,
> 
> We could create a new test for that, but we need to start in on
> source/destination, I thought it just made things more complicated.
> 
> If your preffer that way, please suggest how/what?

I mean, an isolated test that only runs a single VM instance rather
than two (so no test_migrate_start() at all), but only: qtest_init(),
then qmp() to send the deprecated commands, then query to see whether
the values are set.  That's all.  Can that work for us?

-- 
Peter Xu