Re: [PATCH v2 3/3] migration-test: Make sure that multifd and cancel works

[Juan Quintela <quintela@redhat.com>]

"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:
> * Juan Quintela (quintela@redhat.com) wrote:
>> Test that this sequerce works:
>> 
>> - launch source
>> - launch target
>> - start migration
>> - cancel migration
>> - relaunch target
>> - do migration again
>> 
>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>> 
>> ---
>> 
>> - Wait for 1st trhead to move to cancelled before launching second
>>   migration
>> - Add 'to2' parameter to diferentiate 1st and second target.
>> ---
>>  tests/migration-test.c | 110 ++++++++++++++++++++++++++++++++++++++++-
>>  1 file changed, 109 insertions(+), 1 deletion(-)
>> 
>> diff --git a/tests/migration-test.c b/tests/migration-test.c
>> index 1a8d06718e..7a833d65ce 100644
>> --- a/tests/migration-test.c
>> +++ b/tests/migration-test.c
>> @@ -387,6 +387,14 @@ static void migrate_recover(QTestState *who, const char *uri)
>>      qobject_unref(rsp);
>>  }
>>  
>> +static void migrate_cancel(QTestState *who)
>> +{
>> +    QDict *rsp;
>> +
>> +    rsp = wait_command(who, "{ 'execute': 'migrate_cancel' }");
>> +    qobject_unref(rsp);
>> +}
>> +
>>  static void migrate_set_capability(QTestState *who, const char *capability,
>>                                     bool value)
>>  {
>> @@ -419,6 +427,8 @@ static void migrate_postcopy_start(QTestState *from, QTestState *to)
>>  typedef struct {
>>      bool hide_stderr;
>>      bool use_shmem;
>> +    /* only launch the target process */
>> +    bool only_target;
>>      char *opts_source;
>>      char *opts_target;
>>  } MigrateStart;
>> @@ -534,7 +544,9 @@ static int test_migrate_start(QTestState **from, QTestState **to,
>>                                   arch_source, shmem_opts, args->opts_source,
>>                                   ignore_stderr);
>>      g_free(arch_source);
>> -    *from = qtest_init(cmd_source);
>> +    if (!args->only_target) {
>> +        *from = qtest_init(cmd_source);
>> +    }
>>      g_free(cmd_source);
>>  
>>      cmd_target = g_strdup_printf("-accel kvm -accel tcg%s%s "
>> @@ -1257,6 +1269,101 @@ static void test_multifd_tcp(void)
>>      free(uri);
>>  }
>>  
>> +/*
>> + * This test does:
>> + *  source               target
>> + *                       migrate_incoming
>> + *     migrate
>> + *     migrate_cancel
>> + *                       launch another target
>> + *     migrate
>> + *
>> + *  And see that it works
>> + */
>> +
>> +static void test_multifd_tcp_cancel(void)
>> +{
>> +    MigrateStart *args = migrate_start_new();
>> +    QTestState *from, *to, *to2;
>> +    QDict *rsp;
>> +    char *uri;
>> +
>> +    args->hide_stderr = true;
>> +
>> +    if (test_migrate_start(&from, &to, "defer", args)) {
>> +        return;
>> +    }
>> +
>> +    /*
>> +     * We want to pick a speed slow enough that the test completes
>> +     * quickly, but that it doesn't complete precopy even on a slow
>> +     * machine, so also set the downtime.
>> +     */
>> +    /* 1 ms should make it not converge*/
>> +    migrate_set_parameter_int(from, "downtime-limit", 1);
>> +    /* 1GB/s */
>> +    migrate_set_parameter_int(from, "max-bandwidth", 1000000000);
>
> See previous comment about my update in the postcopy test, but OK.

Yes and no O:-)

function                 value
--------                 -----
postcopy_prepare            30 000 000
precopy_unix             1 000 000 000
xbzrle                   1 000 000 000
precpy_tcp               1 000 000 000
fd_proto                 1 000 000 000
auto-converge            1 000 000 000
multifd                  1 000 000 000
multifd_cancel           1 000 000 000

Can we agree to create three global constants with the following values:


const long long downtime_initial = 1;
const long long downtime_final = 300;  /* or ever 600 */
const long long bandwidth_initial = 30 000 000;

And substitute everywhere with the rigths constants?

Thanks, Juan.

>> +    migrate_set_parameter_int(from, "multifd-channels", 16);
>> +    migrate_set_parameter_int(to, "multifd-channels", 16);
>> +
>> +    migrate_set_capability(from, "multifd", "true");
>> +    migrate_set_capability(to, "multifd", "true");
>> +
>> +    /* Start incoming migration from the 1st socket */
>> +    rsp = wait_command(to, "{ 'execute': 'migrate-incoming',"
>> +                           "  'arguments': { 'uri': 'tcp:127.0.0.1:0' }}");
>> +    qobject_unref(rsp);
>> +
>> +    /* Wait for the first serial output from the source */
>> +    wait_for_serial("src_serial");
>> +
>> +    uri = migrate_get_socket_address(to, "socket-address");
>> +
>> +    migrate_qmp(from, uri, "{}");
>> +
>> +    wait_for_migration_pass(from);
>> +
>> +    migrate_cancel(from);
>
> You might want to add something here to validate that the cancel has
> finished before starting the new one.


>> +    args = migrate_start_new();
>> +    args->only_target = true;
>> +
>> +    if (test_migrate_start(&from, &to2, "defer", args)) {
>> +        return;
>> +    }
>> +
>> +    migrate_set_parameter_int(to2, "multifd-channels", 16);
>> +
>> +    migrate_set_capability(to2, "multifd", "true");
>> +
>> +    /* Start incoming migration from the 1st socket */
>> +    rsp = wait_command(to2, "{ 'execute': 'migrate-incoming',"
>> +                            "  'arguments': { 'uri': 'tcp:127.0.0.1:0' }}");
>> +    qobject_unref(rsp);
>> +
>> +    /* 300ms it should converge */
>> +    migrate_set_parameter_int(from, "downtime-limit", 300);
>> +
>> +    uri = migrate_get_socket_address(to2, "socket-address");
>> +
>> +    wait_for_migration_status(from, "cancelled", NULL);

That is exactly what this last line does, not?
The rest of things that we do here are for "to2" instance, that don't
affect us at all.

Once told that, I think that it makes sense to just move the set of
downtime-limit after the migration.

Thanks, Juan.


>> +
>> +    migrate_qmp(from, uri, "{}");
>> +
>> +    wait_for_migration_pass(from);
>> +
>> +    if (!got_stop) {
>> +        qtest_qmp_eventwait(from, "STOP");
>> +    }
>> +    qtest_qmp_eventwait(to2, "RESUME");
>> +
>> +    wait_for_serial("dest_serial");
>> +    wait_for_migration_complete(from);
>> +    test_migrate_end(from, to2, true);
>> +    free(uri);
>> +}
>> +
>>  int main(int argc, char **argv)
>>  {
>>      char template[] = "/tmp/migration-test-XXXXXX";
>> @@ -1322,6 +1429,7 @@ int main(int argc, char **argv)
>>  
>>      qtest_add_func("/migration/auto_converge", test_migrate_auto_converge);
>>      qtest_add_func("/migration/multifd/tcp", test_multifd_tcp);
>> +    qtest_add_func("/migration/multifd/tcp/cancel", test_multifd_tcp_cancel);
>>  
>>      ret = g_test_run();
>>  
>> -- 
>> 2.24.1
>> 
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK