Re: [Qemu-devel] [PATCH v4 3/3] tests/migration: Add a test for auto converge

[Dr. David Alan Gilbert]

* Dr. David Alan Gilbert (address@hidden) wrote:
> * Yury Kotov (address@hidden) wrote:
> > Signed-off-by: Yury Kotov <address@hidden>
> 
> OK, I think that's worth a go; lets see how it does in heavy CI systems/
> 
> Dave

and I meant:


Reviewed-by: Dr. David Alan Gilbert <address@hidden>

> > ---
> >  tests/migration-test.c | 103 ++++++++++++++++++++++++++++++++++++-----
> >  1 file changed, 92 insertions(+), 11 deletions(-)
> > 
> > diff --git a/tests/migration-test.c b/tests/migration-test.c
> > index a4feb9545d..b783ae47b3 100644
> > --- a/tests/migration-test.c
> > +++ b/tests/migration-test.c
> > @@ -241,6 +241,17 @@ static int64_t read_ram_property_int(QTestState *who, 
> > const char *property)
> >      return result;
> >  }
> >  
> > +static int64_t read_migrate_property_int(QTestState *who, const char 
> > *property)
> > +{
> > +    QDict *rsp_return;
> > +    int64_t result;
> > +
> > +    rsp_return = migrate_query(who);
> > +    result = qdict_get_try_int(rsp_return, property, 0);
> > +    qobject_unref(rsp_return);
> > +    return result;
> > +}
> > +
> >  static uint64_t get_migration_pass(QTestState *who)
> >  {
> >      return read_ram_property_int(who, "dirty-sync-count");
> > @@ -255,20 +266,22 @@ static void read_blocktime(QTestState *who)
> >      qobject_unref(rsp_return);
> >  }
> >  
> > +static bool check_migration_status(QTestState *who, const char *status)
> > +{
> > +    bool completed;
> > +    char *current_status;
> > +
> > +    current_status = migrate_query_status(who);
> > +    completed = strcmp(current_status, status) == 0;
> > +    g_assert_cmpstr(current_status, !=, "failed");
> > +    g_free(current_status);
> > +    return completed;
> > +}
> > +
> >  static void wait_for_migration_status(QTestState *who,
> >                                        const char *goal)
> >  {
> > -    while (true) {
> > -        bool completed;
> > -        char *status;
> > -
> > -        status = migrate_query_status(who);
> > -        completed = strcmp(status, goal) == 0;
> > -        g_assert_cmpstr(status, !=,  "failed");
> > -        g_free(status);
> > -        if (completed) {
> > -            return;
> > -        }
> > +    while (!check_migration_status(who, goal)) {
> >          usleep(1000);
> >      }
> >  }
> > @@ -1121,6 +1134,73 @@ static void test_migrate_fd_proto(void)
> >      test_migrate_end(from, to, true);
> >  }
> >  
> > +static void test_migrate_auto_converge(void)
> > +{
> > +    char *uri = g_strdup_printf("unix:%s/migsocket", tmpfs);
> > +    QTestState *from, *to;
> > +    int64_t remaining, percentage;
> > +
> > +    /*
> > +     * We want the test to be fast enough, but stable.
> > +     * Throttle percentages are chosen to cover all cases (init, 
> > increment, max)
> > +     */
> > +    static const int64_t expected_pcts[] = { 0, 1, 51, 98 };
> > +    const int64_t max_bandwidth = 200000000; /* ~200Mb/s */
> > +    const int64_t downtime_limit = 50; /* 50ms */
> > +    /*
> > +     * We migrate through unix-socket (> 500Mb/s).
> > +     * Thus, expected migration speed ~= bandwidth limit (< 500Mb/s).
> > +     * So, we can predict expected_threshold
> > +     */
> > +    const int64_t expected_threshold = max_bandwidth * downtime_limit / 
> > 1000;
> > +
> > +    if (test_migrate_start(&from, &to, uri, false, false)) {
> > +        return;
> > +    }
> > +
> > +    migrate_set_capability(from, "auto-converge", true);
> > +    migrate_set_parameter_int(from, "cpu-throttle-initial", 
> > expected_pcts[1]);
> > +    migrate_set_parameter_int(from, "cpu-throttle-increment",
> > +                              expected_pcts[2] - expected_pcts[1]);
> > +    migrate_set_parameter_int(from, "max-cpu-throttle", expected_pcts[3]);
> > +
> > +    migrate_set_parameter_int(from, "max-bandwidth", max_bandwidth);
> > +    migrate_set_parameter_int(from, "downtime-limit", downtime_limit);
> > +
> > +    /* To check remaining size after precopy */
> > +    migrate_set_capability(from, "pause-before-switchover", true);
> > +
> > +    /* Wait for the first serial output from the source */
> > +    wait_for_serial("src_serial");
> > +
> > +    migrate(from, uri, "{}");
> > +
> > +    /*
> > +     * Wait for pre-switchover status to check last throttle percentage
> > +     * and remaining. These values will be zeroed later
> > +     */
> > +    wait_for_migration_status(from, "pre-switchover");
> > +
> > +    /* We expect that migration can't converge without throttling */
> > +    percentage = read_migrate_property_int(from, 
> > "cpu-throttle-percentage");
> > +    g_assert_cmpint(percentage, >, 0);
> > +
> > +    remaining = read_ram_property_int(from, "remaining");
> > +    g_assert_cmpint(remaining, <, expected_threshold);
> > +
> > +    wait_command(from, "{ 'execute': 'migrate-continue' , 'arguments':"
> > +                       "  { 'state': 'pre-switchover' } }");
> > +
> > +    qtest_qmp_eventwait(to, "RESUME");
> > +
> > +    wait_for_serial("dest_serial");
> > +    wait_for_migration_complete(from);
> > +
> > +    g_free(uri);
> > +
> > +    test_migrate_end(from, to, true);
> > +}
> > +
> >  int main(int argc, char **argv)
> >  {
> >      char template[] = "/tmp/migration-test-XXXXXX";
> > @@ -1176,6 +1256,7 @@ int main(int argc, char **argv)
> >      /* qtest_add_func("/migration/ignore_shared", test_ignore_shared); */
> >      qtest_add_func("/migration/xbzrle/unix", test_xbzrle_unix);
> >      qtest_add_func("/migration/fd_proto", test_migrate_fd_proto);
> > +    qtest_add_func("/migration/auto_converge", test_migrate_auto_converge);
> >  
> >      ret = g_test_run();
> >  
> > -- 
> > 2.22.0
> > 
> --
> Dr. David Alan Gilbert / address@hidden / Manchester, UK
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK