From: Rusty Russell <rusty@rustcorp.com.au>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Shirley Ma <mashirle@us.ibm.com>,
Herbert Xu <herbert@gondor.hengli.com.au>,
davem@davemloft.net, kvm@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCH 2/2] virtio_net: remove send completion interrupts and avoid TX queue overrun through packet drop
Date: Mon, 04 Apr 2011 15:43:41 +0930 [thread overview]
Message-ID: <87mxk6bl2i.fsf@rustcorp.com.au> (raw)
In-Reply-To: <20110327075254.GA3776@redhat.com>
On Sun, 27 Mar 2011 09:52:54 +0200, "Michael S. Tsirkin" <mst@redhat.com> wrote:
> > Though IIRC, qemu's virtio barfs if the first descriptor isn't just the
> > hdr (barf...).
>
> Maybe we can try fixing this before adding more flags,
> then e.g. publish used flag can be resued to also
> tell us layout is flexible. Or just add a feature flag for that.
We should probably do this at some stage, yes.
> > > 2. I didn't have time to work on virtio2 ideas presented
> > > at the kvm forum yet, any takers?
> >
> > I didn't even attend.
>
> Hmm, right. But what was presented there was discussed on list as well:
> a single R/W descriptor ring with valid bit instead of 2 rings
> + a descriptor array.
I'll be happy when we reach the point that the extra cacheline is
hurting us :)
Then we should do direct descriptors w/ a cookie as the value to hand
back when finished. That seems to be close to optimal.
> I agree absolutely that not all lessons has been learned,
> playing with different ring layouts would make at least
> an interesting paper IMO.
Yes, I'd like to see the results...
Thanks,
Rusty.
next prev parent reply other threads:[~2011-04-04 7:03 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-17 0:12 [PATCH 2/2] virtio_net: remove send completion interrupts and avoid TX queue overrun through packet drop Shirley Ma
2011-03-17 5:02 ` Michael S. Tsirkin
2011-03-17 15:18 ` Shirley Ma
2011-03-18 3:28 ` Shirley Ma
2011-03-18 13:15 ` Michael S. Tsirkin
2011-03-18 16:54 ` Shirley Ma
2011-03-17 5:10 ` Rusty Russell
2011-03-17 15:10 ` Shirley Ma
2011-03-18 13:33 ` Herbert Xu
2011-03-19 1:41 ` Shirley Ma
2011-03-21 18:03 ` Shirley Ma
2011-03-22 11:36 ` Michael S. Tsirkin
2011-03-23 2:26 ` Shirley Ma
2011-03-24 0:30 ` Rusty Russell
2011-03-24 4:14 ` Shirley Ma
2011-03-24 14:28 ` Michael S. Tsirkin
2011-03-24 17:46 ` Shirley Ma
2011-03-24 18:10 ` Michael S. Tsirkin
2011-03-25 4:51 ` Rusty Russell
2011-03-25 4:50 ` Rusty Russell
2011-03-27 7:52 ` Michael S. Tsirkin
2011-04-04 6:13 ` Rusty Russell [this message]
2011-03-24 0:16 ` Rusty Russell
2011-03-24 6:39 ` Michael S. Tsirkin
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