Re: [Qemu-devel] [PATCH 4/6] tests: Add migration xbzrle test

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

* Juan Quintela (quintela@redhat.com) wrote:
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
>  tests/migration-test.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 80 insertions(+)
> 
> diff --git a/tests/migration-test.c b/tests/migration-test.c
> index 8549e4c2c6..f0734e4ba0 100644
> --- a/tests/migration-test.c
> +++ b/tests/migration-test.c
> @@ -422,6 +422,23 @@ static void migrate_set_parameter(QTestState *who, const char *parameter,
>      QDECREF(rsp);
>  }
>  
> +static void migrate_set_capability(QTestState *who, const char *capability,
> +                                   const char *value)
> +{
> +    QDict *rsp;
> +    gchar *cmd;
> +
> +    cmd = g_strdup_printf("{ 'execute': 'migrate-set-capabilities',"
> +                          "'arguments': { "
> +                            "'capabilities': [ { "
> +                              "'capability': '%s', 'state': %s } ] } }",
> +                          capability, value);
> +    rsp = qtest_qmp(who, cmd);
> +    g_free(cmd);
> +    g_assert(qdict_haskey(rsp, "return"));
> +    QDECREF(rsp);
> +}
> +
>  static void migrate_set_downtime(QTestState *who, const char *value)
>  {
>      QDict *rsp;
> @@ -448,6 +465,19 @@ static void migrate_set_speed(QTestState *who, const char *value)
>      QDECREF(rsp);
>  }
>  
> +static void migrate_set_cache_size(QTestState *who, const char *value)
> +{
> +    QDict *rsp;
> +    gchar *cmd;
> +
> +    cmd = g_strdup_printf("{ 'execute': 'migrate-set-cache-size',"
> +                          "'arguments': { 'value': %s } }", value);
> +    rsp = qtest_qmp(who, cmd);
> +    g_free(cmd);
> +    g_assert(qdict_haskey(rsp, "return"));
> +    QDECREF(rsp);
> +}
> +
>  static void test_precopy_deprecated(const char *uri)
>  {
>      QTestState *from, *to;
> @@ -543,6 +573,55 @@ static void test_precopy_tcp(void)
>      test_precopy(uri);
>  }
>  
> +static void test_xbzrle(const char *uri)
> +{
> +    QTestState *from, *to;
> +
> +    test_migrate_start(&from, &to, uri);
> +
> +    /* 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.
> +     */
> +    /* 100 ms */
> +    migrate_set_parameter(from, "downtime-limit", "100");
> +    /* 1MB/s slow*/
> +    migrate_set_parameter(from, "max-bandwidth", "100000000");
> +
> +    migrate_set_cache_size(from, "50000000");

Why 50MB?  I guess this is an interesting test; the program
dirties 100MB of RAM repeatedly, one byte/page.  So 50MB is probably
not much use becuase it'll thrash.

> +    migrate_set_capability(from, "xbzrle", "true");
> +    migrate_set_capability(to, "xbzrle", "true");
> +    /* Wait for the first serial output from the source */
> +    wait_for_serial("src_serial");
> +
> +    migrate(from, uri);
> +
> +    wait_for_migration_pass(from);
> +
> +    /* 1GB/s now it should converge */
> +    migrate_set_parameter(from, "max-bandwidth", "1000000000");

I wonder about doing a set_cache_size 150MB here, with a delay before
the max-bandwidht?  If we're lucky at 150MB it'll start actually using
the XBZRLE compression.

> +    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);

Extract xbzrle stats?

Dave

> +}
> +
> +static void test_xbzrle_unix(void)
> +{
> +    char *uri = g_strdup_printf("unix:%s/migsocket", tmpfs);
> +
> +    test_xbzrle(uri);
> +    g_free(uri);
> +}
> +
> +
>  int main(int argc, char **argv)
>  {
>      char template[] = "/tmp/migration-test-XXXXXX";
> @@ -561,6 +640,7 @@ int main(int argc, char **argv)
>      qtest_add_func("/migration/precopy/unix", test_precopy_unix);
>      qtest_add_func("/migration/precopy/tcp", test_precopy_tcp);
>      qtest_add_func("/migration/deprecated/unix", test_deprecated_unix);
> +    qtest_add_func("/migration/xbzrle/unix", test_xbzrle_unix);
>  
>      ret = g_test_run();
>  
> -- 
> 2.13.5
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK