Re: [Qemu-devel] [PATCH v6 15/19] migration: Create thread infrastructure for multifd recv side

[Peter Xu <peterx@redhat.com>]

On Tue, Aug 08, 2017 at 06:26:25PM +0200, Juan Quintela wrote:
> We make the locking and the transfer of information specific, even if we
> are still receiving things through the main thread.
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> 
> --
> 
> We split when we create the main channel and where we start the main
> migration thread, so we wait for the creation of the other threads.
> 
> Use multifd_clear_group().
> ---
>  migration/migration.c |  7 ++++---
>  migration/migration.h |  1 +
>  migration/ram.c       | 55 +++++++++++++++++++++++++++++++++++++++++++++++----
>  migration/socket.c    |  2 +-
>  4 files changed, 57 insertions(+), 8 deletions(-)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index 8e9505a..b78dffc 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -381,7 +381,7 @@ static void migration_incoming_setup(QEMUFile *f)
>      qemu_file_set_blocking(f, false);
>  }
>  
> -static void migration_incoming_process(void)
> +void migration_incoming_process(void)
>  {
>      Coroutine *co = qemu_coroutine_create(process_incoming_migration_co, NULL);
>      qemu_coroutine_enter(co);
> @@ -400,9 +400,10 @@ void migration_ioc_process_incoming(QIOChannel *ioc)
>      if (!mis->from_src_file) {
>          QEMUFile *f = qemu_fopen_channel_input(ioc);
>          mis->from_src_file = f;
> -        migration_fd_process_incoming(f);
> +        migration_incoming_setup(f);

Here now we only setup the incoming channels, but not processing it
any more. Then would it be good we rename the function name as well?
The old "migration_ioc_process_incoming" has hints that it processed
something... And...

> +        return;
>      }
> -    /* We still only have a single channel.  Nothing to do here yet */
> +    multifd_new_channel(ioc);
>  }

[...]

> @@ -183,12 +183,12 @@ static gboolean socket_accept_incoming_migration(QIOChannel *ioc,
>  
>      qio_channel_set_name(QIO_CHANNEL(sioc), "migration-socket-incoming");
>      migration_channel_process_incoming(QIO_CHANNEL(sioc));
> -    object_unref(OBJECT(sioc));
>  
>  out:
>      if (migration_has_all_channels()) {
>          /* Close listening socket as its no longer needed */
>          qio_channel_close(ioc, NULL);
> +        migration_incoming_process();

... here we only added migration_incoming_process() for sockets. Would
that break fd/exec migration?

Thanks,

>          return G_SOURCE_REMOVE;
>      } else {
>          return G_SOURCE_CONTINUE;

-- 
Peter Xu