Re: [Qemu-devel] [PATCH 05/12] migration: show the statistics of compression

[Xiao Guangrong]

On 06/14/2018 12:25 AM, Dr. David Alan Gilbert wrote:
 }
> >   
> >   static void migration_bitmap_sync(RAMState *rs)
> > @@ -1412,6 +1441,9 @@ static void flush_compressed_data(RAMState *rs)
> >           qemu_mutex_lock(&comp_param[idx].mutex);
> >           if (!comp_param[idx].quit) {
> >               len = qemu_put_qemu_file(rs->f, comp_param[idx].file);
> > +            /* 8 means a header with RAM_SAVE_FLAG_CONTINUE. */
> > +            compression_counters.reduced_size += TARGET_PAGE_SIZE - len + 8;
>
> I think I'd rather save just len+8 rather than than the subtraction.
Hmmmmmm, is this what you want?
      compression_counters.reduced_size += len - 8;

Then calculate the real reduced size in populate_ram_info() where we return this
info to the user:
      info->compression->reduced_size = compression_counters.pages * PAGE_SIZE 
- compression_counters.reduced_size;

Right?

> I think other than that, and Eric's comments, it's OK.

Thanks.