> I could reproduce this very well on a random OS image that I had around.
> This is raw over XFS over dm-crypt, and the image is about 75% sparse
> (8.2G used over 35G). I only get 1-2%, but still it's visible.
>
> However I can hardly reproduce it when using a partition directly:
>
> old new
> mean 9.9565 9.9636 (+0.07%)
> stddev 0.0405 0.0537
> min 9.871 9.867
> median 9.973 9.971
> max 10.01 10.053
> count 20 20
>
> I haven't tried removing layers (e.g. fully-allocated XFS image without
> dm-crypt).
Could not reproduce it with a fully-allocated XFS image, on the contrary
the patched QEMU is a bit faster:
old new
mean 14.83325 14.82660
stddev 0.016930 0.010328
min 14.819 14.818
max 14.854 14.883
median 14.8225 14.8255
count 20 20
Paolo
