Re: [Qemu-devel] [PATCH v5 14/17] migration: Delay the start of reception on main channel

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

* Juan Quintela (quintela@redhat.com) wrote:
> When we start multifd, we will want to delay the main channel until
> the others are created.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
>  migration/migration.c | 23 ++++++++++++++---------
>  1 file changed, 14 insertions(+), 9 deletions(-)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index d9d5415..e122684 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -358,14 +358,11 @@ static void process_incoming_migration_co(void *opaque)
>  
>  static void migration_incoming_setup(QEMUFile *f)
>  {
> -    MigrationIncomingState *mis = migration_incoming_get_current();
> -
>      if (multifd_load_setup() != 0) {
>          /* We haven't been able to create multifd threads
>             nothing better to do */
>          exit(EXIT_FAILURE);
>      }
> -    mis->from_src_file = f;
>      qemu_file_set_blocking(f, false);
>  }
>  
> @@ -384,18 +381,26 @@ void migration_fd_process_incoming(QEMUFile *f)
>  gboolean migration_ioc_process_incoming(QIOChannel *ioc)
>  {
>      MigrationIncomingState *mis = migration_incoming_get_current();
> +    gboolean result = FALSE;

I wonder if we need some state somewhere so that we can see that the
incoming migration is partially connected - since the main incoming
coroutine hasn't started yet, we've not got much of mis setup.

Dave

>      if (!mis->from_src_file) {
>          QEMUFile *f = qemu_fopen_channel_input(ioc);
>          mis->from_src_file = f;
> -        migration_fd_process_incoming(f);
> -        if (!migrate_use_multifd()) {
> -            return FALSE;
> -        } else {
> -            return TRUE;
> +        migration_incoming_setup(f);
> +        if (migrate_use_multifd()) {
> +            result = TRUE;
>          }
> +    } else {
> +        /* we can only arrive here if multifd is on
> +           and this is a new channel */
> +        result = multifd_new_channel(ioc);
>      }
> -    return multifd_new_channel(ioc);
> +    if (result == FALSE) {
> +        /* called when !multifd and for last multifd channel */
> +        migration_incoming_process();
> +    }
> +
> +    return result;
>  }
>  
>  /*
> -- 
> 2.9.4
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK