On 03.10.19 19:15, Vladimir Sementsov-Ogievskiy wrote:
> Large copy range may imply memory allocation and large io effort, so
> using 2G copy range request may be bad idea. Let's limit it to 16 MiB.
> It also helps the following patch to refactor copy-with-offload
> fallback to copy-with-bounce-buffer.
> 
> Note, that total memory usage of backup is still not limited, it will
> be fixed in further commit.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>  block/block-copy.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)

Reviewed-by: Max Reitz <mreitz@redhat.com>