OK, a bit more data:
Xenial with 4.4 and 4.8 kernels - works fine (so not a 4.8 kernel regression) Yakkety with 4.4 and 4.8 kernels - shows the slow behavior (so not a kernel issue)
So I think this is a problem in the plumbing layer.
OK, a bit more data:
Xenial with 4.4 and 4.8 kernels - works fine (so not a 4.8 kernel regression)
Yakkety with 4.4 and 4.8 kernels - shows the slow behavior (so not a kernel issue)
So I think this is a problem in the plumbing layer.