RFT: ZFS MFC

[Pete French]

> Many people are happily running an old pool with the new code. I have
> done that in a VM and run load over it just to be certain. The tuning
> still applies to i386. On amd64 vm backpressure works, but may
> actually be too aggressive - shrinking the ARC in favor of the
> inactive pages queue.

I haven't had any i386 code around for a long while, so I will just
try it "as-is". Just need to fin ish moving tghe machine up to todays
-STABLE before applying the patchset (which involved hand fixing bce).

Then, all being well I shall "(the_winds)caution" to coin an old
C joke, and run this up on one of our production DNS servers to
see how it goes.

cheers,

-pete.