Re: [Qemu-devel] [PATCH 7/8] migration: introduce save_normal_page()

[Dr. David Alan Gilbert]

* address@hidden (address@hidden) wrote:
> From: Xiao Guangrong <address@hidden>
> 
> It directly sends the page to the stream neither checking zero nor
> using xbzrle or compression
> 
> Signed-off-by: Xiao Guangrong <address@hidden>

Reviewed-by: Dr. David Alan Gilbert <address@hidden>

> ---
>  migration/ram.c | 50 ++++++++++++++++++++++++++++++--------------------
>  1 file changed, 30 insertions(+), 20 deletions(-)
> 
> diff --git a/migration/ram.c b/migration/ram.c
> index 9627ce18e9..f778627992 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -995,6 +995,34 @@ static bool control_save_page(RAMState *rs, RAMBlock 
> *block, ram_addr_t offset,
>      return true;
>  }
>  
> +/*
> + * directly send the page to the stream
> + *
> + * Returns the number of pages written.
> + *
> + * @rs: current RAM state
> + * @block: block that contains the page we want to send
> + * @offset: offset inside the block for the page
> + * @buf: the page to be sent
> + * @async: send to page asyncly
> + */
> +static int save_normal_page(RAMState *rs, RAMBlock *block, ram_addr_t offset,
> +                            uint8_t *buf, bool async)
> +{
> +    ram_counters.transferred += save_page_header(rs, rs->f, block,
> +                                                 offset | 
> RAM_SAVE_FLAG_PAGE);
> +    if (async) {
> +        qemu_put_buffer_async(rs->f, buf, TARGET_PAGE_SIZE,
> +                              migrate_release_ram() &
> +                              migration_in_postcopy());
> +    } else {
> +        qemu_put_buffer(rs->f, buf, TARGET_PAGE_SIZE);
> +    }
> +    ram_counters.transferred += TARGET_PAGE_SIZE;
> +    ram_counters.normal++;
> +    return 1;
> +}
> +
>  /**
>   * ram_save_page: send the given page to the stream
>   *
> @@ -1035,18 +1063,7 @@ static int ram_save_page(RAMState *rs, 
> PageSearchStatus *pss, bool last_stage)
>  
>      /* XBZRLE overflow or normal page */
>      if (pages == -1) {
> -        ram_counters.transferred +=
> -            save_page_header(rs, rs->f, block, offset | RAM_SAVE_FLAG_PAGE);
> -        if (send_async) {
> -            qemu_put_buffer_async(rs->f, p, TARGET_PAGE_SIZE,
> -                                  migrate_release_ram() &
> -                                  migration_in_postcopy());
> -        } else {
> -            qemu_put_buffer(rs->f, p, TARGET_PAGE_SIZE);
> -        }
> -        ram_counters.transferred += TARGET_PAGE_SIZE;
> -        pages = 1;
> -        ram_counters.normal++;
> +        pages = save_normal_page(rs, block, offset, p, send_async);
>      }
>  
>      XBZRLE_cache_unlock();
> @@ -1172,14 +1189,7 @@ static int ram_save_compressed_page(RAMState *rs, 
> PageSearchStatus *pss,
>           * we post it as normal page as compression will take much
>           * CPU resource.
>           */
> -        ram_counters.transferred += save_page_header(rs, rs->f, block,
> -                                        offset | RAM_SAVE_FLAG_PAGE);
> -        qemu_put_buffer_async(rs->f, p, TARGET_PAGE_SIZE,
> -                              migrate_release_ram() &
> -                              migration_in_postcopy());
> -        ram_counters.transferred += TARGET_PAGE_SIZE;
> -        ram_counters.normal++;
> -        pages = 1;
> +        pages = save_normal_page(rs, block, offset, p, true);
>      } else {
>          pages = compress_page_with_multi_thread(rs, block, offset);
>      }
> -- 
> 2.14.3
> 
> 
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK