re: [PATCH v2 06/24] migration: Run a post update routine after setting parameters

[Fabiano Rosas <farosas@suse.de>]

Bin Guo <guobin@linux.alibaba.com> writes:

> Fabiano Rosas wrote on Mon, 30 Jun 2025 16:58:55 -0300:
>
>> Some migration parameters are updated immediately once they are set
>> via migrate-set-parameters. Move that work outside of
>> migrate_params_apply() and leave that function with the single
>> responsibility of setting s->parameters and not doing any
>> side-effects.
>> 
>> Reviewed-by: Peter Xu <peterx@redhat.com>
>> Signed-off-by: Fabiano Rosas <farosas@suse.de>
>> 
>> diff --git a/migration/options.c b/migration/options.c
>> index 295367ce92..1f8a977865 100644
>> --- a/migration/options.c
>> +++ b/migration/options.c
>> @@ -1083,6 +1083,31 @@ void migrate_params_init(MigrationParameters *params)
>>      params->has_direct_io = true;
>>  }
>>  
>> +static void migrate_post_update_params(MigrationParameters *new, Error **errp)
>> +{
>> +    MigrationState *s = migrate_get_current();
>> +
>> +    if (new->has_max_bandwidth) {
>> +        if (s->to_dst_file && !migration_in_postcopy()) {
>> +            migration_rate_set(new->max_bandwidth);
>> +        }
>> +    }
>> +
>> +    if (new->has_x_checkpoint_delay) {
>> +        colo_checkpoint_delay_set();
>> +    }
>> +
>> +    if (new->has_xbzrle_cache_size) {
>> +        xbzrle_cache_resize(new->xbzrle_cache_size, errp);
>> +    }
>> +
>> +    if (new->has_max_postcopy_bandwidth) {
>> +        if (s->to_dst_file && migration_in_postcopy()) {
>> +            migration_rate_set(new->max_postcopy_bandwidth);
>> +        }
>> +    }
>> +}
>> +
>>
>> diff --git a/migration/ram.c b/migration/ram.c
>> index 2140785a05..7432f82bdd 100644
>> --- a/migration/ram.c
>> +++ b/migration/ram.c
>> @@ -174,7 +174,7 @@ static void XBZRLE_cache_unlock(void)
>>  /**
>>   * xbzrle_cache_resize: resize the xbzrle cache
>>   *
>> - * This function is called from migrate_params_apply in main
>> + * This function is called from migrate_post_update_config in main
>>   * thread, possibly while a migration is in progress.  A running
>>   * migration may be using the cache and might finish during this call,
>>   * hence changes to the cache are protected by XBZRLE.lock().
>> -- 
>
> The function is migrate_post_update_params, 
> but the comment says migrate_post_update_config.
>

Nice catch, this series is a pain to rebase, a lot of cross-references
between patches. I'll fix.

> --
> Regards,
> Bin Guo