On Sun, Jun 12, 2005 at 03:29:45AM +0000, Jed Davis wrote:
> [...]
> > 3) If you only merge forward in the ring, you can't break filesystem
> >    ordering constraints, but you _will_ fix the problem where 64K from
> >    the client turns into 44K + 20K.
> 
> And the forward-only merging is what I had in mind.  But more to the
> point, if the client was expecting ordering constraints to be honored,
> it was already getting an unpleasant surprise since, as I understand it,
> we were just tossing a bunch of bufs into the queue at once and handling
> the completions whenever they came back --- to say nothing of whatever
> the Linux backend is doing.

You're right. One thing that I forgot in this picture is disksort() at
the underlying disk driver.

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 26 ans d'experience feront toujours la difference
--