Subject: Re: CVS commit: src/sys/arch/xen/xen
To: YAMAMOTO Takashi <>
From: Manuel Bouyer <>
List: source-changes
Date: 10/06/2005 22:02:54
On Thu, Oct 06, 2005 at 03:36:33PM +0900, YAMAMOTO Takashi wrote:
> > > i think that it's better to have xennetback_tx_free() take xni_pkt
> > > rather than xni_page.
> > 
> > Ha, so we could acknowledge the packets sooner, that's your point ?
> yes.
> > My idea was to defer packets ack as much as possible, to have a larger
> > batch of packets to process in the frontend, and reduce the number of
> > events sent to the frontend.
> txring->event isn't enough?

In SMP systems I think there can be races between the domains on this,
leading to a number of interrupt several times larger than what it should be.
But with the other changes I've made, maybe this isn't an issue any more,
and releasing the ring slot sooner may lead to less pages map/unmap.
I'll do more tests on this.

Manuel Bouyer <>
     NetBSD: 26 ans d'experience feront toujours la difference