On Thu, Mar 30 2017, Brad Campbell wrote:

>        [==============>......]  recovery = 72.0% (4222847296/5860391360) 
> finish=541.6min speed=50382K/sec
...
>        [==============>......]  recovery = 73.3% (4297641980/5860391360) 
> finish=284.7min speed=91465K/sec
>

>
> So that has significantly increased the rebuild speed, as you would expect.
>

Not quite twice as fast, but close!
Everyone has been suffering with that poor speed for years and nobody
noticed until you did.  Thanks for being thorough!  And thanks for
confirming the patch.

NeilBrown