Re: [PATCH 0/12] virtio_net perf patches

Anthony Liguori
2008-08-11T20:30:57Z

Mark McLoughlin wrote:
> Hi Avi,
> Here's the set of patches that I think make sense to apply.
>

We probably need to disable checksum offload on the RX side until we
figure out what to do about the broken dhclient. That's going to hit a
lot of users otherwise.

Regards,

Anthony Liguori

> I've left out Anthony's zero-copy patch since I wasn't seeing
> a measurable difference with it, it's quite invasive and isn't safe
> with the "drop the global mutex during tapfd read()" patch.
>
> I left that mutex patch 'til last since you may still be
> nervous about concurrency issues and also the posix-timers kernel race
> that it triggers.
>
> Another change since the first round of patches is that it
> took a bit of ugly hackery to handle the case where IFF_VNET_HDR
> is supported and we're using e.g. e1000. Since it's difficult to
> only enable IFF_VNET_HDR when we're using virtio_net_hdr, I went with
> this approach.
>
> Lastly, I need to add a "vnet_hdr=on" param to "-net tap" so
> that we can know if the supplied tap fd has IFF_VNET_HDR enabled.
> There's no interface to query that on the fd right now, and even if
> I did cook up a patch it probably wouldn't make 2.6.27.
>
> Cheers,
> Mark.
>
>
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