Re: [PATCH v4 1/4] multifd: Create property multifd-sync-after-each-section

[Markus Armbruster <armbru@redhat.com>]

Juan Quintela <quintela@redhat.com> writes:

> We used to synchronize all channels at the end of each RAM section
> sent.  That is not needed, so preparing to only synchronize once every
> full round in latests patches.
>
> Notice that we initialize the property as true.  We will change the
> default when we introduce the new mechanism.
>
> 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>
>
> ---
>
> Rename each-iteration to after-each-section
>
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---

[...]

> diff --git a/migration/migration.c b/migration/migration.c
> index a5c22e327d..b2844d374f 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -167,7 +167,8 @@ INITIALIZE_MIGRATE_CAPS_SET(check_caps_background_snapshot,
>      MIGRATION_CAPABILITY_XBZRLE,
>      MIGRATION_CAPABILITY_X_COLO,
>      MIGRATION_CAPABILITY_VALIDATE_UUID,
> -    MIGRATION_CAPABILITY_ZERO_COPY_SEND);
> +    MIGRATION_CAPABILITY_ZERO_COPY_SEND,
> +    MIGRATION_CAPABILITY_MULTIFD_SYNC_AFTER_EACH_SECTION);
>  
>  /* When we add fault tolerance, we could have several
>     migrations at once.  For now we don't need to add
> @@ -2705,6 +2706,15 @@ bool migrate_use_multifd(void)
>      return s->enabled_capabilities[MIGRATION_CAPABILITY_MULTIFD];
>  }
>  
> +bool migrate_multifd_sync_after_each_section(void)
> +{
> +    MigrationState *s = migrate_get_current();
> +
> +    return true;
> +    // We will change this when code gets in.

It seems the time for that would be right now, doesn't it?  ;)

> +    return s->enabled_capabilities[MIGRATION_CAPABILITY_MULTIFD_SYNC_AFTER_EACH_SECTION];
> +}
> +
>  bool migrate_pause_before_switchover(void)
>  {
>      MigrationState *s;
> @@ -4539,7 +4549,8 @@ static Property migration_properties[] = {
>      DEFINE_PROP_MIG_CAP("x-zero-copy-send",
>              MIGRATION_CAPABILITY_ZERO_COPY_SEND),
>  #endif
> -
> +    DEFINE_PROP_MIG_CAP("multifd-sync-after-each-section",
> +                        MIGRATION_CAPABILITY_MULTIFD_SYNC_AFTER_EACH_SECTION),
>      DEFINE_PROP_END_OF_LIST(),
>  };