On Thu, Jul 09, 2015 at 11:47:58AM +0800, Fam Zheng wrote:
> Limiting to sectors_per_chunk for each bdrv_is_allocated_above is slow,
> because the underlying protocol driver would issue much more queries
> than necessary. We should coalesce the query.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  block/mirror.c | 15 ++++++---------
>  1 file changed, 6 insertions(+), 9 deletions(-)

Thanks, applied Patch 3 to my block tree:
https://github.com/stefanha/qemu/commits/block

Stefan