On Wed, Aug 29, 2007 at 08:31:59AM +0100, Stephen Borrill wrote:
> >at the same time (or how much interfaces in a single domU)
> 
> I've doubled it and also now the domU is the only one on the box. The 
> performance problems are still happening.

Another thing that can happen (I ran into this recently) is that when
the ring is full, the transmit stops and won't restart a soon as there is
some place in the ring, because there's no interrupt mechanism in the Xen2
interface to allow this (we have to poll for the ring pointers and notice when
there's some space). Xen3 is much better in this area.

-- 
Manuel Bouyer, LIP6, Universite Paris VI.           Manuel.Bouyer@lip6.fr
     NetBSD: 26 ans d'experience feront toujours la difference
--