Am 13.01.2016 um 09:37 hat Fam Zheng geschrieben: > Two empty raw files are always compared by actually reading data even if > there is no data, because BDRV_BLOCK_ZERO is considered "allocated" in > bdrv_is_allocated_above(). That is inefficient. > > Use bdrv_get_block_status_above() for more information, and skip the > consecutive zero sectors. > > This brings a huge speed up in comparing sparse/empty raw images: > > $ qemu-img create a 1G > > $ time ~/build/master/bin/qemu-img compare a a > Images are identical. > > real 0m6.583s > user 0m0.191s > sys 0m6.367s > > $ time qemu-img compare a a > Images are identical. > > real 0m0.033s > user 0m0.003s > sys 0m0.031s > > Signed-off-by: Fam Zheng <f...@redhat.com>
Thanks, applied to the block branch. Kevin
