Re: [PATCH v4 07/23] multifd: Use proper maximum compression values

[Dr. David Alan Gilbert]

* Juan Quintela (quintela@redhat.com) wrote:
> It happens that there are functions to calculate the worst possible
> compression size for a packet.  Use them.
> 
> Suggested-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Signed-off-by: Juan Quintela <quintela@redhat.com>

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> ---
>  migration/multifd-zlib.c | 4 ++--
>  migration/multifd-zstd.c | 4 ++--
>  2 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/migration/multifd-zlib.c b/migration/multifd-zlib.c
> index 9f6ebf1076..a2fec4d01d 100644
> --- a/migration/multifd-zlib.c
> +++ b/migration/multifd-zlib.c
> @@ -54,8 +54,8 @@ static int zlib_send_setup(MultiFDSendParams *p, Error 
> **errp)
>          error_setg(errp, "multifd %u: deflate init failed", p->id);
>          return -1;
>      }
> -    /* To be safe, we reserve twice the size of the packet */
> -    z->zbuff_len = MULTIFD_PACKET_SIZE * 2;
> +    /* This is the maxium size of the compressed buffer */
> +    z->zbuff_len = compressBound(MULTIFD_PACKET_SIZE);
>      z->zbuff = g_try_malloc(z->zbuff_len);
>      if (!z->zbuff) {
>          deflateEnd(&z->zs);
> diff --git a/migration/multifd-zstd.c b/migration/multifd-zstd.c
> index cc4e991724..97c08367d0 100644
> --- a/migration/multifd-zstd.c
> +++ b/migration/multifd-zstd.c
> @@ -67,8 +67,8 @@ static int zstd_send_setup(MultiFDSendParams *p, Error 
> **errp)
>                     p->id, ZSTD_getErrorName(res));
>          return -1;
>      }
> -    /* To be safe, we reserve twice the size of the packet */
> -    z->zbuff_len = MULTIFD_PACKET_SIZE * 2;
> +    /* This is the maxium size of the compressed buffer */
> +    z->zbuff_len = ZSTD_compressBound(MULTIFD_PACKET_SIZE);
>      z->zbuff = g_try_malloc(z->zbuff_len);
>      if (!z->zbuff) {
>          ZSTD_freeCStream(z->zcs);
> -- 
> 2.34.1
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK