On Tue, Oct 04, 2005 at 12:10:20AM +0900, YAMAMOTO Takashi wrote:
> > > - as you defer ack until xennetback_tx_free and the mbuf can live ~forever,
> > >   you can capture all buffers.
> > >   (i think that linux netback has the same problem.)
> > 
> > I wondered about this. Can the kernel really grab a mbuf forever ? For
> > which reason ?
> 
> eg. when an application never read from the socket.

Ha yes, I focused on network interfaces communications and forgot this
case.

> 
> > An easy fix would be to switch back to copy when we are low on buffers.
> 
> yes, it can be a workaround.

As this is something that actually can (and will) happen, I'll look at
implementing this workaround.

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