Re: [PATCH v5 03/14] migration: Simplify migration_iteration_run()

[Alex Williamson]

On Thu, 29 Dec 2022 13:03:34 +0200
Avihai Horon <avihaih@nvidia.com> wrote:

> From: Juan Quintela <quintela@redhat.com>

IMHO, there should always be a commit log description.  Why is this a
simplification?  What does it allow us to do?  Nothing later obviously
depends on this, why is it part of this series?  Thanks,

Alex

> Signed-off-by: Juan Quintela <quintela@redhat.com>
> Signed-off-by: Avihai Horon <avihaih@nvidia.com>
> ---
>  migration/migration.c | 25 +++++++++++++------------
>  1 file changed, 13 insertions(+), 12 deletions(-)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index 9795d0ec5c..61b9ce0fe8 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -3758,23 +3758,24 @@ static MigIterateState 
> migration_iteration_run(MigrationState *s)
>      trace_migrate_pending(pending_size, s->threshold_size,
>                            pend_pre, pend_compat, pend_post);
>  
> -    if (pending_size && pending_size >= s->threshold_size) {
> -        /* Still a significant amount to transfer */
> -        if (!in_postcopy && pend_pre <= s->threshold_size &&
> -            qatomic_read(&s->start_postcopy)) {
> -            if (postcopy_start(s)) {
> -                error_report("%s: postcopy failed to start", __func__);
> -            }
> -            return MIG_ITERATE_SKIP;
> -        }
> -        /* Just another iteration step */
> -        qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
> -    } else {
> +
> +    if (!pending_size || pending_size < s->threshold_size) {
>          trace_migration_thread_low_pending(pending_size);
>          migration_completion(s);
>          return MIG_ITERATE_BREAK;
>      }
>  
> +    /* Still a significant amount to transfer */
> +    if (!in_postcopy && pend_pre <= s->threshold_size &&
> +        qatomic_read(&s->start_postcopy)) {
> +        if (postcopy_start(s)) {
> +            error_report("%s: postcopy failed to start", __func__);
> +        }
> +        return MIG_ITERATE_SKIP;
> +    }
> +
> +    /* Just another iteration step */
> +    qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
>      return MIG_ITERATE_RESUME;
>  }
>