Re: [PATCH 3/4] migration-test: Make sure that multifd and cancel works

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* 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>
> ---
>  tests/migration-test.c | 108 ++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 107 insertions(+), 1 deletion(-)
> 
> diff --git a/tests/migration-test.c b/tests/migration-test.c
> index 7588f50b9b..1c93b3e5bc 100644
> --- a/tests/migration-test.c
> +++ b/tests/migration-test.c
> @@ -527,6 +527,14 @@ 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)
>  {
> @@ -583,6 +591,8 @@ 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;
> @@ -704,7 +714,9 @@ 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("-machine %saccel=kvm:tcg%s "
> @@ -1470,6 +1482,99 @@ static void test_multifd_tcp_zstd(void)
>      test_multifd_tcp("zstd");
>  }
>  
> +/*
> + * 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;
> +    QDict *rsp;
> +    char *uri;
> +
> +    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);

This is copied from postcopy_prepare, note that I dropped that bandwidth
quite a bit in 513aa2c because we were seeing TCG on slow hosts converge
even at 1ms, because the vCPU wasn't dirtying pages quickly.

> +    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(from, uri, "{}");
> +
> +    wait_for_migration_pass(from);
> +
> +    printf("before cancel\n");
> +    migrate_cancel(from);
> +    printf("after cancel\n");

Do you really want those printf's for normal operation?

> +    args = migrate_start_new();
> +    args->only_target = true;
> +
> +    if (test_migrate_start(&from, &to, "defer", args)) {
> +        return;
> +    }
> +
> +    migrate_set_parameter_int(to, "multifd-channels", 16);
> +
> +    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);
> +
> +    /* 300ms it should converge */
> +    migrate_set_parameter_int(from, "downtime-limit", 600);

Comment doesn't match parameter!

With those fixed;


Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> +    uri = migrate_get_socket_address(to, "socket-address");
> +
> +    migrate(from, uri, "{}");
> +
> +    wait_for_migration_pass(from);
> +
> +    if (!got_stop) {
> +        qtest_qmp_eventwait(from, "STOP");
> +    }
> +    qtest_qmp_eventwait(to, "RESUME");
> +
> +    wait_for_serial("dest_serial");
> +    wait_for_migration_complete(from);
> +    test_migrate_end(from, to, true);
> +    free(uri);
> +}
> +
>  int main(int argc, char **argv)
>  {
>      char template[] = "/tmp/migration-test-XXXXXX";
> @@ -1537,6 +1642,7 @@ int main(int argc, char **argv)
>      qtest_add_func("/migration/multifd/tcp/none", test_multifd_tcp_none);
>      qtest_add_func("/migration/multifd/tcp/zlib", test_multifd_tcp_zlib);
>      qtest_add_func("/migration/multifd/tcp/zstd", test_multifd_tcp_zstd);
> +    qtest_add_func("/migration/multifd/tcp/cancel", test_multifd_tcp_cancel);
>  
>      ret = g_test_run();
>  
> -- 
> 2.23.0
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK